فهرست مطالب

پژوهش های صنایع غذایی - سال سی‌ام شماره 3 (پاییز 1399)
  • سال سی‌ام شماره 3 (پاییز 1399)
  • تاریخ انتشار: 1399/09/26
  • تعداد عناوین: 15
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  • هلیا آقامحسنی، وجیهه فدائی نوغانی*، مهناز خدایی جویاری صفحات 1-18

    در این پژوهش، تاثیر بازدارنده های پروتیازی عصاره دانه سویا (0، 100، 300 و 500 واحد بازدارنده تریپسین)،لوبیا چشم بلبلی(0، 100، 300 و 500 واحد بازدارنده تریپسین)و ترکیبی از عصاره های دانه سویا(50، 150 و 250 واحد بازدارنده تریپسین)و لوبیا چشم بلبلی (50، 150 و 250 واحد بازدارنده تریپسین) بر برخی ویژگی های نمونه های خامه پاستوریزه طی13روزدر فواصل 3 روزه بررسی شد. نتایج نشان داد که در اسیدیته،ویسکوزیته، آب اندازی، اندیس پراکسید،اندیس آنیزیدین و شمارش کلی میکروبی، اختلاف معنی داری میان تیمارها و طی نگهداری وجود دارد(05/0p <) بطوری که اسیدیته،ویسکوزیته،آب اندازی،اندیس پراکسید با افزودن عصاره ها افزایش و اندیس آنیزیدین و شمارش کلی میکروبی کاهش یافت و اسیدیته،میزان آب اندازی،فعالیت کلی میکروبی واندیس پراکسید و اندیس آنیزیدین در طی زمان افزایش اما ویسکوزیته طی نگهداری کاهش یافت.در میزان بازدارندگی پروتیازی تمامی تیمارهای حاوی عصاره سویا و لوبیا چشم بلبلی،اختلاف معنی داری ملاحظه شد(05/0p <)؛اما اختلاف طی نگهداری معنی دار نبود(05/0p>)و غلظت بالاتر عصاره ها، درصد بازدارندگی بالاتری را ایجاد نمود. در نتیجه میزان بازدارندگی تحت تاثیر غلظت بودو چون درصد بازدارندگی نمونه حاوی عصاره دانه سویا با فعالیت TIU/ml 500 بیشتر از نمونه حاوی عصاره دانه سویابا فعالیت TIU/ml250و عصاره دانه لوبیا چشم بلبلی با فعالیت TIU/ml 250 می باشد؛ می توان گفت عصاره دانه سویا توانسته است قوی تر از عصاره دانه لوبیا چشم بلبلی عمل نماید.درآزمون حسی،اختلاف معنی داری میان تیمارها و طی نگهداری مشاهده نشد(05/0p>).در نهایت،نمونه حاوی TIU/ml 500 سویا به دلیل ویژگی های فیزیکوشیمیایی مناسب و ویژگی های میکروبی و حسی مقبول، به عنوان تیمار برتر معرفی شد.

    کلیدواژگان: بازدارنده پروتئازی، تلخی، خامه پاستوریزه، عصاره دانه سویا، عصاره دانه لوبیا چشم بلبلی
  • مینا سیف زاده*، علی اصغر خانی پور صفحات 19-31
    زمینه مطالعاتی

    بتاکاروتن پیش نیاز ویتامین A و از افزودنی های غذایی است. بتا کاروتن در صنعت از طریق سنتز شیمیایی از β-ionone تهیه می شود. این رنگ از ترکیبات سنتتیک هست، که می تواند به آسانی از طریق مواد غذایی به مصرف کنندگان منتقل شود. بنابراین تحقیق در زمینه تهیه رنگ های طبیعی برای کاربرد در صنعت غذایی از اهمیت خاصی برخوردار است.

    هدف

    این پروژه باهدف تعیین مقدار، کیفیت، درصد خلوص بتا کاروتن استخراج شده از آزولای تالاب انزلی در فصل زمستان و مقایسه آن با نوع سنتتیک انجام شد.

    روش ها

    برای اجرای این پروژه یک تیمار شامل بتا کاروتن استخراج شده به روش هیدرولیز قلیایی از آزولای تالاب انزلی در فصل زمستان سال 1393در نظر گرفته شد. تیمارها به مدت یک سال در دمای پنج درجه سلسیوس نگهداری شدند. از بتا کاروتن سنتتیک به عنوان شاهد استفاده شد. کیفیت تیمارها با استفاده از آزمایش های شیمیایی شامل تعیین مقدار و کیفیت بتا کاروتن، رنگ سنجی (هانترلپ)، درصد خلوص و ویتامین A به وسیله HPLC ، زمان ماندگاری و حلالیت بتا کاروتن طبیعی بررسی شد.

    نتایج

    در نتایج آزمایش های شامل درصد خلوص، غلظت، رنگ سنجی، ترکیبات ویتامینه، حلالیت و زمان ماندگاری در بتا کاروتن آزمایشی در مقایسه با شاهد تفاوت معنی دار مشاهده نشد(05/0>P) طی زمان ماندگاری این فاکتورها در تیمارهای آزمایشی و شاهد تفاوت معنی دار نشان ندادند(05/0>P). بتا کاروتن طبیعی طی زمان نگهداری به مدت یک سال در دمای 5 درجه سلسیوس از کیفیت مطلوبی برخوردار بود. نتیجه گیری نهایی: با توجه به عدم وجود تفاوت معنی دار بین بتا کاروتن استخراج شده از آزولا در مقایسه با نوع سنتتیک از حیث آزمایش های شیمیایی، خلوص، زمان ماندگاری و ارجحیت بتا کاروتن طبیعی استخراج شده از آزولا در مقایسه با نوع سنتتیک از حیث بهداشت مواد غذایی می توان کاربرد بتا کاروتن طبیعی تهیه شده از آزولا را به جای بتا کاروتن سنتتیک در صنعت غذایی پیشنهاد کرد.

    کلیدواژگان: آزولا، رنگ دانه های طبیعی، بتا کاروتن، افزودنی غذایی، تالاب انزلی
  • صابر امیری، رضا رضایی مکرم*، محمود صوتی خیابانی، محمود رضازاد باری، محمد علیزاده صفحات 33-49

    اسید لاکتیک (2- هیدروکسی پروپونیک اسید) یک اسید آلی مهم با کاربردهای گسترده در صنایع غذایی، داروسازی، مواد شوینده و کشاورزی است. بدین منظور اثر مواد مغذی و فاکتورهای محیطی مهم در تولید اسید لاکتیک با استفاده از محصول جانبی حاصل از کارخانجات لبنی (آب پنیر و پرمیات شیر) به عنوان محیط کشت توسط کشت های خالص لاکتوباسیلوس اسیدوفیلوس LA5 و بیفیدوباکتریوم انیمالیس زیرگونه لاکتیس BB12 مورد بررسی قرار گرفت. نتایج تجزیه و تحلیل آماری داده ها نشان دهنده اثر معنی دار pH اولیه، دمای گرمخانه گذاری، غلظت عصاره مخمر، نوع محیط کشت و نوع باکتری بر تولید اسید لاکتیک بود (05/0p <). زمان گرمخانه گذاری، نوع باکتری پروبیوتیک و غلظت عصاره مخمر اثر معنی دار بر تراکم سلولی داشت (05/0p <). همچنین اثر pH اولیه، دما و زمان گرمخانه گذاری، غلظت عصاره مخمر، نوع محیط کشت و باکتری پروبیوتیک بر pH معنی دار بود (05/0p <). نتایج این مطالعه نشان داد که پرمیات شیر و آب پنیر به علت محتوای بالای لاکتوز می تواند محیط کشت مناسبی برای تولید اسید لاکتیک باشد ولی بررسی هزینه های کاربرد مکمل های غذایی بویژه منبع نیتروژن ضروری است.

    کلیدواژگان: اسید لاکتیک، آب پنیر، پرمیات شیر، لاکتوباسیلوس اسیدوفیلوس LA5، بیفیدوباکتریوم لاکتیس BB12
  • محمدرضا صیادی، ژاله خوشخو*، قربان زارع گشتی صفحات 51-63

    در این تحقیق ازگوشت چرخ شده ماهی سیم به دلیل رنگ و بوی مناسب بصورت تلفیقی با گوشت چرخ شده گوساله استفاده از 100٪ گوشت چرخ شده ماهی (تیمار 1) ، 100٪ گوشت قرمز (تیمار2) تلفیقی از 50% +50% ماهی و گوشت گوساله (تیمار3) عمل آوری در پوشش های پلی اتیلنی بسته بندی و مدت 15 روز در دمای یخچالoc 4 نگهداری و شاخص های ارزش غذایی ، pH و TBArs در طول زمان ارزیابی و نتایج نشان داد اسیدهای چرب اشباع در همه تیمارها حفظ شده و مقدار مریسیتیک اسید در گوشت ماهی سیم (تیمار1) بطور معنی داری بیشتر از تیمار 2 و 3 بوده و پالمتیک اسید فرآوانترین اسید چرب اشباع در تیمارهای تحقیق بود. در اسیدهای چرب غیراشباع MUFA ، میریستیک و پالمیتولییک در تیمار 1 بالاتر از سایر تیمارها بود اما اسید های چرب مارگاریک و الایدیک در تیمار 2 بالاتر از سایر تیمارها بوده است.

    کلیدواژگان: ماهی سیم (Abramis brama)، اسیدهای چرب اشباع، اسیدهای چرب غیراشباع، شاخص های فساد
  • جابر سلیمانی*، منصوره مظفری صفحات 65-76
    زمینه مطالعاتی

    طبیعت فاسد شدنی میوه ی زردآلو به دلیل فرازگرا بودن و تولید اتیلن، باعث کاهش مدت انبارداری آن می شود.

    هدف

    در این بررسی سعی شد با تحقیق بر روی فن آوری بسته بندی با اتمسفر تغییر یافته، تولید اتیلن را کاهش داده و عمر انباری این میوه را افزایش داد.

    روش کار

    طرح آزمایشی مورد استفاده کرت خرد شده بر پایه ی طرح کامل تصادفی شامل دو کرت در سه تکرار بود. کرت اصلی شامل زمان در چهار سطح (روز چهارم، روز هشتم، روز دوازدهم و روز شانزدهم) و کرت فرعی شامل نوع ترکیب گازی مورد استفاده با پوشش های متفاوت در شش سطح 3% O2 + 5% CO2 با پوشش پلی پروپیلن با ضخامت 2/. میلی متر، 3% O2 + 10% CO2 با پوشش پلی پروپیلن با ضخامت 2/. میلی متر، 3% O2 + 5% CO2 با پوشش پلی پروپیلن با ضخامت 4/. میلی متر، 3% O2 + 10% CO2 تحت پوشش پلی پروپیلن با ضخامت 4/. میلی متر، بسته بندی فقط با پوشش پلی پروپیلن با ضخامت 2/. میلی متر و بسته بندی فقط با پوشش پلی پروپیلن با ضخامت 4/. میلی متر بود. صفات مورد اندازه گیری شامل TSS، pH، کاهش وزن، سفتی و EC در میوه های زردآلو بود.

    نتیجه گیری نهایی

    نتایج حاصل نشان داد که با افزایش مدت زمان نگهداری زردآلو تمام صفات اندازه گیری شده TSS، pH وEC افزایش در حالی که سفتی میوه کاهش نشان داد. از نظر نوع ترکیب گازی با پوشش های متفاوت، تیمار 3% O2 + 10% CO2 با پوشش پلی پروپیلن به ضخامت 4/0 باعث افزایش عمر انباری زردآلو شد، به طوری که این تیمار توانست عمر انباری زردآلو رقم قرمز شاهرود را حدود 3 برابر افزایش دهد. ضخامت فیلم تاثیر معنی داری بر افزایش عمر انباری میوه زردآلو نداشت.

    کلیدواژگان: زردآلو، اتمسفر تغییر یافته، اکسیژن، دی اکسید کربن
  • اکرم شریفی*، نسیم پور ابراهیم، مریم ملکی، نسیم دیواندری صفحات 77-87

    سس سالسا یکی از محصولات محبوب و پرمصرف گوجه فرنگی است که حاوی قطعات گوجه فرنگی، پیاز، سیر، فلفل دلمه ای، نمک، سبزیجات معطر، ادویه جات و اسید می باشد. در این پژوهش برخی از خواص فیزیکی و شیمیایی سس سالسا مانند اسیدیته، قند کل، نمک، مواد جامد محلول در آب، pH و خاکستر کل و پارامترهای ریولوژیکی سس سالسا با استفاده از ویسکومتر بروکفیلد در سه دمای 5، 25 و °C 45 و در سه سطح مختلف صمغ های زانتان و گوار شامل (زانتان 100 % ، گوار 100% و زانتان و گوار 50-50%) اندازه گیری شد. محاسبات انجام شده براساس روش میچکا نشان داد که سس سالسا دارای رفتار غیر نیوتنی از نوع قانون توان است. n یا شاخص رفتار جریان برای همه نمونه ها در محدوده (282/0 تا 378/0) و ضریب پایداری (k) بین (91/1 تا 12/3) بدست آمد. شاخص رفتار جریان کوچکتر از یک نشان دهنده رفتار رقیق شوندگی با برش یا سودوپلاستیسیته نمونه های سس سالسا بود که با افزایش دما، مقادیر شاخص جریان رفتار (n) و ضریب پایداری (k) کاهش یافتند. همچنین با استفاده از معادله آرنیوس تابعیت ضریب پایداری سس سالسا با دما تعیین و انرژی فعالسازی بین KJ mol-1 2135/3 تا 947/10 بدست آمد. سس سالسای حاوی صمغ گوار و زانتان دارای کمترین انرژی فعال سازی بود و بعد از آن سس حاوی 100 درصد زانتان قرار داشت این سس در دمای 5 درجه سانتی گراد بیشترین ضریب پایداری را نشان داد و بنابراین از ویژگی های ریولوژیکی مناسب تری نسبت به سایر نمونه ها برخوردار بود.

    کلیدواژگان: سالسا، گوار، زانتان، ضریب پایداری، روش میچکا
  • آزاده شاهسون تبریزی، اسماعیل عطای صالحی*، زهرا شیخ الاسلامی صفحات 89-105

    از مشکلات اصلی نان های امروزی که به موازات کاهش راندمان استخراج آرد تشدید می شود، می توان به افت خواص حسی به ویژه رنگ، خواص بافتی و تسریع در روند بیاتی آن ها اشاره نمود. که عمدتا ناشی از کم بودن محتوای فیبری آن ها به واسطه کاهش یا حذف سبوس از آردهای سفید است. استفاده از منابع مختلف نظیر آرد سویا که آنزیم لیپوکسیژناز آن فعال باشد، یکی از راه های مناسب جهت بهبود ویژگی های کیفی، رنگبری برای آرد و کاهش بیاتی نان است. در این پژوهش اثر افزودن مقادیر صفر، 4، 8 و 12 درصد آرد سویای فعال بر خواص کیفی، بافت، بیاتی، رنگ و تخلخل نان قالبی مورد بررسی قرار گرفت. نتایج به وضوح نشان داد که افزایش درصد آرد سویای فعال باعث افزایش مولفه L* نان می شود، و بیاتی نان را به تاخیر می اندازد، بیشترین میزان مولفه L* پوسته مربوط به نمونه با 12 درصد آرد سویای فعال برابر 72 و کمترین میزان آن مربوط به نمونه شاهد برابر 61 بود. با افزایش درصد آرد سویا مولفه *a پوسته و مغز نان کاهش یافت، همچنین با افزایش میزان آرد سویای فعال میزان تخلخل نمونه‏ها نسبت به نمونه شاهد به طور معنی‏داری کاهش یافت. با افزایش درصد آرد سویا میزان حجم مخصوص نان کاهش یافت، افزودن آرد سویا بیشتر از 4 درصد اثر منفی روی حجم نان داشت. افزودن 4 درصد آرد سویا تاثیر معنی داری روی سفتی ندارد ولی افزودن بیشتر از 4 درصد در هر دو زمان سبب افزایش این پارامتر می گردد. ولی افزایش بیش از 4 درصد آرد سویا روی بافت و برخی خواص حسی مانند طعم، بو و ظاهر اثر منفی داشت. استفاده از آرد سویای فعال در تولید نان قالبی سبب بهبود خصوصیات کیفی محصول نهایی، کاهش بیاتی و به دنبال آن کاهش ضایعات در این نان می گردد.

    کلیدواژگان: آرد سویای فعال، بافت، بیاتی، نان قالبی
  • اکرم پزشکی*، مریم خاکباز حشمتی، زهرا ابوطالبی صفحات 107-121

    روغن آفتابگردان یکی از مهم ترین روغن های خوراکی است که به دلیل دارا بودن بندهای دوگانه و غیراشباعیت نسبتا بالا مستعد فساد اکسیداسیونی می باشد. در مطالعه حاضر، عصاره متانولی استخراج شده از دو گیاه آویشن و زنجبیل به عنوان آنتی اکسیدان طبیعی در روغن آفتابگردان استفاده گردید و خاصیت آنتی اکسیدانی آنها در غلظت (300 پی پی ام) به تنهایی و در مخلوط با هم در مقایسه با آلفا توکوفرول صنعتی در غلظت (200 پی پی ام) در جلوگیری از اکسیداسیون روغن آفتابگردان بررسی شد. آزمون هایی ازجمله بررسی اسیدیته، اندیس های پراکسید، تیوباربیتوریک اسید، فنول کل و فعالیت آنتی اکسیدانی بررسی گردیدند. نتایج نشان داد اسیدیته تمامی نمونه ها در طی 45 روز نگهداری در دمای محیط (25 درجه سانتی گراد) به طور معنی داری افزایش یافته است. میزان اندیس پراکسید و تیوباربیتوریک اسید در طی مدت نگهداری به طور معنی داری افزایش یافت. کمترین میزان اندیس پراکسید و تیوباربیوتیک اسید پس از 45 روز مربوط به نمونه های حاوی آلفا توکوفرول و 300 پی پی ام عصاره متانولی آویشن و زنجبیل توام بود. درصد مهار رادیکال های آزاد تمامی نمونه های روغن به طور معنی داری در طی 45 روز نگهداری کاهش یافت . بیشترین درصد مهار این رادیکال ها مربوط به نمونه حاوی آلفا توکوفرول بود و پس از آن نیز نمونه حاوی 300 پی پی ام عصاره متانولی آویشن و زنجبیل توام باهم، دارای بیشترین درصد مهار بود. در کل می توان نتیجه گیری نمود عصاره متانولی انواع اسانس های روغنی (زنجبیل وآویشن) را می توان به عنوان آنتی اکسیدان طبیعی برای مهار اکسیداسیون روغن های خوراکی با درجه غیراشباعیت بالا از جمله روغن آفتابگردان استفاده نمود. .

    کلیدواژگان: روغن آفتابگردان، زنجبیل، آویشن، پایداری اکسیداتیو، فعالیت آنتی اکسیدانی
  • داوود عطائی، زهره حمیدی اصفهانی*، حسن احمدی گاولیقی صفحات 123-135

    زایلان هسته خرما رقم کبکاب استخراج و با استفاده از دو زایلاناز تجاری به نام پنتوپان منو بی جی و ورون 191 آبکافت گردید. نوع و کمیت زایلوالیگوساکاریدهای موجود در دو محلول زایلوالیگوساکاریدی، به وسیله کروماتوگرافی مایعی با کارایی بالا به روش تعویض یونی تعیین گردید. برای سنجش قابلیت هضمی، محلول های زایلوالیگوساکاریدی در معرض محلول هایی شبیه شیره های گوارشی قرار گرفت. نتایج نشان داد که این زایلوالیگوساکاریدها مقاوم به هضم هستند. همچنین اثر زایلوالیگوساکارید های حاصل، به عنوان منبع کربنی، بر رشد بیفیدوباکتریوم بیفیدوم، در مقایسه با دیگر منابع کربنی مورد ارزیابی قرار گرفت. نتایج نشان داد که بین زایلوالیگوساکاریدهای مورد نظر و منابع کربنی دیگر و گروه کنترل از نظر اثر بر سرعت رشد حداکثر باکتری و دانسیته نوری بعد از 24 ساعت، تفاوت معنی داری وجود دارد اما بین دو زایلوالیگوساکارید حاصل از آنزیم پنتوپان منو بی جی و ورون 191 تفاوتی در سطح 95٪ مشاهده نشد. pH محیط های کشت نیز در این فواصل زمانی اندازه گرفته شد. کاهش pH محیط های دارای زایلوالگوساکارید، بیشتر از منابع کربنی دیگر بود که نشان دهنده تولید بیشتر اسیدهای آلی بوده است. در مجموع به دلیل هضم ناپذیری زایلوالیگوساکاریدهای به دست آمده از آبکافت آنزیمی زایلان هسته خرما و اثر مثبت بر رشد بیفیدوباکتریوم بیفیدوم ، می توان خاصیت بالقوه پری بیوتیکی به آنها نسبت داد.

    کلیدواژگان: پروبیوتیک، پری بیوتیک، زایلوالیگوساکارید، هسته خرما، هضم پذیری
  • داود مزیدی، سید حسین حسینی قابوس* صفحات 137-149

    به دلیل مشکلات زیست محیطی ناشی از کاربرد فیلم های مصنوعی، پژوهشگران به تولید پوشش های خوراکی طبیعی برای نگهداری مواد غذایی از جمله میوه ها و سبزی‏ها روی آورده اند و یکی از منابع تهیه آن ها صمغ های گیاهی است. در این پژوهش اثر پوشش دهی با صمغ دانه های بالنگو و ریحان بر عمر انباری و برخی خواص کمی و کیفی میوه هلو طی نگهداری در انبار سرد بررسی شد. بدین منظور یک آزمایش فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار به صورت جداگانه انجام شد. هر آزمایش شامل دو فاکتور تیمار و زمان انبارداری بود. تیمارها به صورت 5 دقیقه غوطه وری میوه ها در محلول آماده شده صمغ با دمای 25 درجه سانتی گراد اعمال گردید و پس از خشک شدن، میوه ها در ظروف پلاستیکی بسته بندی و در دمای 5 درجه سانتی گراد و رطوبت نسبی 90 درصد نگهداری شدند. فاکتور دوم زمان نگهداری در انبار با 4 سطح شامل 1 (شروع انبارداری)، 10، 20 و 30 روز بعد از آن بود. در هر یک از زمان های ذکرشده، میوه ها از انبار خارج شدند و پارامترهای مواد جامد محلول، اسیدیته قابل تیتراسیون، تولید اتیلن، میزان تنفس، فنل کل و ارزیابی حسی در آن ها مورد بررسی قرار گرفت. نتایج نشان داد که استفاده از ترکیب صمغ دانه های بالنگو و ریحان اثر معنی داری بر کاهش میزان تنفس میوه هلو دارد. اثر زمان انبارداری بر تمامی صفات مورد بررسی در هلو معنی دار بود. در پایان انبارداری، مواد جامد محلول و فنل میوه افزایش یافت و اسیدیته قابل تیتراسیون کاهش نشان داد. با توجه به نتایج، استفاده از 1/0 درصد صمغ دانه های بالنگو و ریحان به عنوان پوشش های خوراکی طبیعی به منظور حفظ کیفیت و افزایش عمر انباری میوه هلو توصیه می شود.

    کلیدواژگان: اتیلن، تنفس، هلو، صمغ دانه بالنگو، صمغ دانه ریحان
  • سمیه سلیمانی مهر، زینب رفتنی امیری*، رضا اسماعیل زاده کناری، احسان صادقی صفحات 151-167
    زمینه مطالعاتی

    کاهش باقیمانده آفت کش ها با بهبود کیفیت مواد غذایی و سلامت انسان همراه است.

    هدف

    در این مطالعه، اثر امواج مایکروویو روی میزان باقیمانده آفت کش اورتوساید (با نام تجاری کاپتان) در زردآلوی خشک شده بررسی شد.

    روش کار

    آفت کش کاپتان در سطوح 25، 50 و 75 پی پی بی در قالب طرح کاملا تصادفی با آزمایش فاکتوریل به میوه های خشک شده ارگانیک زردآلو رقم نصیری تلقیح شدند و سپس میزان باقیمانده آفت کش نمونه های تلقیح شده، پس از پرتودهی با امواج مایکروویو (زمان های 5/2 و 5 دقیقه) طی 2 ماه نگهداری تعیین شد. هم چنین، ویژگی های فیزیکوشیمیایی و میکروبی، رنگ و فعالیت آنتی اکسیدانی در نمونه های بدون تلقیح آفت کش پس از پرتودهی با امواج مایکروویو در زمان های متفاوت نگهداری (صفر، 30 و 60 روز) اندازه گیری شدند.

    نتایج

    امواج مایکروویو سبب کاهش معنی دار میزان باقی مانده آفت کش در همه سطوح تلقیح نسبت به نمونه کنترل شد (05/0>p). علاوه بر این، افزایش مدت زمان نگهداری نیز اثر معنی داری بر کاهش میزان آفت کش داشت. همچنین، امواج مایکروویو موجب افزایش میزان ترکیبات فنولی، فعالیت آنتی اکسیدانی، میزان خاکستر و قند احیا و نیز کاهش میزان رطوبت نمونه ها شدند (05/0>p). امواج مایکروویو تعداد کلی میکروارگانیسم ها و تعداد کپک و مخمر نمونه ها را در مقایسه با نمونه کنترل به طور معنی داری کاهش دادند. از طرفی، امواج مایکروویو موجب کاهش فاکتور L* (روشنی) و نیز افزایش فاکتور a* (قرمزی) و b* (زردی) نمونه ها شد (05/0>p).

    نتیجه گیری نهایی

    زمان 5 دقیقه تیمار با امواج مایکروویو در مقایسه با زمان 5/2 دقیقه با تغییرات بیشتری در همه پارامترهای اندازه گیری شده همراه بود ودر کاهش باقیمانده آفت کش کارایی بالاتری داشت.

    کلیدواژگان: امواج مایکروویو، باقی مانده آفت کش، زردآلوی خشک شده، زمان نگهداری، فعالیت آنتی اکسیدانی
  • سیما مهاجرخراسانی، مهران اعلمی*، مهدی کاشانی نژاد، هدی شهیری طبرستانی صفحات 169-187
    زمینه مطالعاتی

    امروزه متداول ترین روش برای افزایش کیفیت محصولات بدون گلوتن استفاده از صمغ می باشد. بر طبق مطالعات اخیر روش های اصلاح فیزیکی مانند تیمار مایکروویو می توانند برای بهبود خصوصیات عملکردی آرد و محصولات پختی بدون گلوتن مورد استفاده قرار گیرند.

    هدف

    از این رو هدف از این پژوهش مقایسه اثر صمغ زانتان و تیمار مایکروویو دانه ارزن بر خصوصیات فیزیکوشیمیایی و حسی کیک بدون گلوتن می باشد.

    روش کار

    در این پژوهش تاثیر صمغ زانتان در دو سطح صفر و 15/0 درصد و تیمار مایکروویو دانه ارزن در سه سطح رطوبت 10، 15 و 20 درصد و سه سطح زمان 30، 60 و 90 ثانیه با توان ثابت 900 وات بر خصوصیات فیزیکوشیمیایی و حسی خمیر و کیک بدون گلوتن حاصل از آرد ارزن و برنج (نسب 50 :50) بررسی و مقایسه شد.

    نتایج

    طبق نتایج به دست آمده، تیمار مایکروویو دانه ارزن موجب کاهش ثقل ویژه و افزایش ویسکوزیته خمیر کیک بدون گلوتن شد (05/0 <p). کیک حاوی آرد حاصل از دانه های تیمار شده در رطوبت 20 درصد و زمان60 و90 ثانیه به طور معنی داری دارای بالاترین میزان حجم، تخلخل و پذیرش حسی در مقایسه با نمونه کنترل و همچنین نمونه حاوی 15/0 درصد صمغ زانتان گردید (05/0 <p). همچنین تیمار حاوی آرد حاصل از دانه ارزن تیمار شده در رطوبت 20 درصد و زمان 90 ثانیه دارای نرمترین بافت و بالاترین میزان محتوی رطوبت طی نگهداری بود (05/0 <p).

    نتیجه گیری نهایی

    براساس یافته های این پژوهش، تیمار مایکروویو دانه ارزن می تواند جایگزین مناسبی برای استفاده از صمغ در کیک بدون گلوتن باشد.

    کلیدواژگان: کیک بدون گلوتن، ارزن، برنج، تیمار مایکروویو، صمغ زانتان
  • خدیجه عباباف، حسین جوینده*، بهزاد ناصحی صفحات 189-201

    در سالهای اخیر استفاده از محصولات سویا به دلیل آگاهی مصرف کنندگان در مورد فواید سویا به طور روزافزونی افزایش یافته است. ماست پروبیوتیک سویا به دلیل داشتن ترکیبات فراسودمندی همچون میکروارگانیسم های پروبیوتیک و پری بیوتیک های طبیعی (رافینوز، استاکیوز)، از اهمیت ویژه ای برخوردار است و جزء فرآورده های سین بیوتیک در نظر گرفته می شود. هدف از انجام این پژوهش، بررسی تاثیر مقادیر مختلف آنزیم TG (0، 015/0، 03/0و 045/0 درصد) و اینولین (0، 1 و 2 درصد) بر ویژگی های فیزیکوشیمیایی و میکروبی ماست سویای سین بیوتیک طی مدت 21 روز نگهداری در یخچال بود. در تولید ماست سویای سین بیوتیک، از لاکتوباسیلوس اسیدوفیلوس La-5 و بیفیدوباکتریوم لاکتیس Bb-12 به عنوان باکتری های پروبیوتیک استفاده گردید. یافته ها نشان داد با افزایش غلظت آنزیم، مقدار اسیدیته و سینرزیس کاهش و میزان pH به طور معنی داری (001/0 <p) افزایش یافت؛ درحالی که تاثیر معنی داری بر ماده خشک مشاهده نشد. همچنین افزایش غلظت اینولین به طور معنی داری باعث افزایش اسیدیته، ماده خشک و کاهش pH و سینرزیس نمونه های ماست گردید(001/0 <p). با گذشت زمان نگهداری مقدار pH و سینرزیس به طور معنی داری کاهش و میزان اسیدیته تا روز چهاردهم افزایش و پس از آن کاهش یافت (001/0 <p). این درحالی است که تغییر معنی داری در میزان ماده خشک مشاهده نشد. بررسی رنگ محصول با دستگاه رنگ سنج نشان داد که تمام متغیرهای مورد بررسی شامل غلظت آنزیم، اینولین و مدت زمان نگهداری اثر معنی داری بر پارامتر های روشنایی (L*)، قرمزی (a*) و زردی (b*) گذاشتند (001/0 <p). همچنین به طور کلی با افزایش غلظت آنزیم و زمان نگهداری تعداد شمارش کلی پروبیوتیک ها کاهش و با افزایش غلظت اینولین تعداد آن ها افزایش یافت (01/0 <p). درهرحال، تعداد باکتری های پروبیوتیک در تمامی نمونه های ماست سویای سین بیوتیک طی مدت 21 روز نگهداری بالاتر از cfu/g 107 تعیین گردید.

    کلیدواژگان: آنزیم ترانس گلوتامیناز، ماست سویا، اینولین، پروبیوتیک، فراسودمند
  • جواد پارسا*، محمداسماعیل امیری، جعفر حاجی لو، فرهنگ رضوی، حمید رهنمون صفحات 203-219
    زمینه مطاالعاتی

    زردآلو (Prunus armeniaca L.) یکی از با اهمیت ترین ومطلوب ترین میوه های مناطق معتدله است.

    هدف

    پوشش دهی محصولات کشاورزی فسادپذیر، یکی از روش های متداول جهت حفظ کیفیت و در نتیجه کاهش ضایعات انبارمانی است. ژل آلویه ورا (Aloe vera) به منظور بهبود روند تغییرات فیزیولوژیکی به مانند حفظ سفتی، جلوگیری از کاهش وزن، افزایش ظرفیت آنتی اکسیدانی در انبارمانی محصولات کشاورزی مورد توجه واستفاده قرار گرفته است.

    روش کار

    به منظور بررسی کاربرد ژل آلویه ورا بر خصوصیات و ویژگی های کیفی میوه دو رقم زردآلو در طی انبارمانی، آزمایشی به صورت فاکتوریل در قالب طرح کاملا تصادفی با چهار تکرار طراحی و اجرا گردید. فاکتورهای این آزمایش شامل ارقام زردآلو (ʼدرشت ملایرʽ و ʼقرمز شاهرودʽ)، غلظت ژل آلویه ورا [شاهد (صفر درصد)، 25 درصد و 33 درصد] و طول دوره نگه داری میوه [صفر (زمان برداشت)، 7، 14 و 21 روز] بودند.

    نتایج

    نتایج نشان داد که تیمار میوه های زردآلو با ژل آلویه ورا به ویژه در غلظت 33 درصد باعث افزایش معنی دار میزان ویتامین ث، اسیددیته قابل تیتراسیون، ظرفیت آنتی اکسدانی و حفظ بهتر سفتی بافت شد، اما در عین حال میزان مواد جامد محلول، کاهش وزن و pH را کاهش داد. همچنین مشخص شد که میزان ویتامین ث، اسیددیته قابل تیتراسیون و سفتی بافت میوه به طور معنی داری در طول انبارداری کاهش یافت، درحالی که میزان مواد جامد محلول، کاهش وزن و ظرفیت آنتی اکسدانی به طور معنی داری افزایش یاقت. در بین ازقام نیز رقم ʼقرمز شاهرودʽ در طول دوره انبارداری داری میزان مواد جامد محلول، کاهش وزن، pH و ظرفیت آنتی اکسیدانی بیشتری بود، درحالی که رقم ʼدرشت ملایرʽ اسیددیته قابل تیتراسیون، سفتی بافت و ویتامین ث بیشتر در پایان دوره انبارداری بود. نتیجه گیری نهایی: سطوح مختلف ژل آلویه ورا در اکثر صفات تاثیر معنی داری داشته و موجب بهبود صفات میوه زردآلودر طول مدت انبارمانی این میوه شد، با توجه به اثرات مثبت مشاهده شده ژل آلویه ورا می تواند به عنوان یک پوشش غذایی مناسب، در دسترس و موثر در افزایش انبارمانی و حفظ کیفیت میوه های زردآلو مورد استفاده قرار گیرد.

    کلیدواژگان: اسید قابل تیتراسیون، زردآلو، ژل آلوئه ورا (Aloe vera)، فعالیت آنتی اکسیدانی، مواد جامد محلول
  • فاطمه جعفری، افشین جوادی* صفحات 221-232

    پسته، یکی از محصولات صادراتی ایران، در شرایط نامساعد در طول دوره انبارمانی، کپک زدگی، آفت زدگی و تولید سموم بویژه آفلاتوکسین توسط آسپرژیلوس پاراسیتیکوس و آسپرژیلوس فلاووس و جذب رطوبت باعث افت شدید کیفیت محصول می شود. هدف از این مطالعه تعیین اثر پوشش دهی پسته با محلول کیتوزان و عصاره برگ گردو در ماندگاری محصول می باشد. برای این منظور پسته ها با استفاده از محلول های 5/1 و 3 % (وزنی/ حجمی) کیتوزان و عصاره برگ گردو تهیه شده به صورت تکی و ترکیبی پوشش دهی شدند و تاثیر آن بر ویژگی های آفات زنده، حسی، عدد پراکسید، شمارش کپک ومخمر و رطوبت طبق استاندارد ملی ایران در طی مدت نگهداری مورد بررسی قرار گرفت و نتایج با آزمون آنالیز واریانس در سطح احتمال 5% تجزیه و تحلیل شدند.پسته های پوشش داده شده به صورت معنی داری از نظر میزان آفات زنده با نوع شاهد متفاوت بود (05/0p <). نتایج نشان داد که در طی مدت نگهداری سه ماهه، پوشش کیتوزان با عصاره گردو، تاثیر معنی داری روی ویژگی های حسی پسته پوشش داده شده نداشت. در هر یک از زمان ها، رطوبت نمونه شاهد (12/3%) نسبت به پسته های پوشش دهی شده (99/4% برای نمونه حاوی 3% کیتوزان و 3% عصاره گردو) به طور معنی داری کمتر بود (05/0p <). با افزایش غلظت کیتوزان، اثر آنتی اکسیدانی و ضد میکروبی و ضد آفاتی آن افزایش یافته و ضمن حفظ ویژگی های حسی به طور موثری در جلوگیری از اکسایش و فعالیت قارچی در پسته موثر بود. کمترین میزان پراکسید برای نمونه حاوی 3% کیتوزان و 5/1% عصاره گردو مشاهده شد. با توجه به نتایج به دست آمده، بهترین غلضت محلول 5/1% کیتوزان و 5/1% عصاره برگ گردو به صورت ترکیبی برای افزایش ماندگاری پسته پیشنهاد شد.

    کلیدواژگان: پوشش دهی، کیتوزان، برگ گردو، پسته
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  • Heliya Aghamohseni, Mahnaz Khodai Jouyari Pages 1-18

    In this study,the effect of protease inhibitors of soybean seed extract (0, 100, 300, 500 Trypsin Inhibitor Units),cowpea(0, 100, 300, 500 Trypsin Inhibitor Units) and the combination of soybean seed extract(50, 150, 250 Trypsin Inhibitor Units) and cowpea (50, 150, 250 Trypsin Inhibitor Units) on some characterictics of pasteurized cream samples over 13 days at 3-day intervals was investigated.The results showed that there was significant difference between the treatments and during storage on acidity,viscosity, syneresis, peroxide value,anisidine index and microbial total count(p < 0.05);so that acidity,viscosity,syneresis,peroxide value increased by adding treatments and anisidine index and microbial total count decreased and acidity, syneresis,microbial total count,peroxide value and anisidine index have been increased during storage but viscosity has decreased during storage.Significant difference in the inhibitory of treatments was observed (p < 0.05)but the difference during storage was not significant (p>0.05)and greater concentration of the extracts has obtained higher percentage of inhibition, and because the percentage of inhibition in the sample containing soybean seed extract with the activity of 500 Trypsin Inhibitor Unit per Milliliter is more than the sample containing soybean seed extract with the activity of 250 Trypsin Inhibitor Unit per Milliliter and cowpea seed extract with the activity of 250 Trypsin Inhibitor Unit per Milliliter , it can be stated that soybean seed extract has act stronger than cowpea seed extract. No significant difference between the treatments and during storage was observed in sensory evaluation (p>0.05).Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics. Finally, the sample containing 500 Trypsin Inhibitor Units of soybean was introduced as the best treatment due to suitable physicochemical and acceptable microbial and sensory characteristics.

    Keywords: Bitterness, Cowpea Seed Extract, Pasteurized Cream, Protease inhibitor, Soybean Seed Extract
  • M Seifzadeh* Pages 19-31
    Background

    Azolla is certainly a valuable laboratory plant that will thrive with very little care. The use of Azolla may be an important factor in the world's future food needs. Azolla is unique because it is one of the fastest growing plants on the planet – yet it does not need any soil to grow. Azolla is a small floating fern and is the only known pteridophyte that lives in symbiosis with a diazotrophic cyanobacterium. Azolla spp. are heterosporous free-floating freshwater ferns that live symbiotically with Anabaena Azollae, a nitrogen-fixing blue-green algae. There are six species of Azolla in the world. Azolla is a genus of aquatic ferns in the family Salviniaceae. The genus Azolla belongs to the single genus family Azollaceae. Azolla filiculoides is a species of Azolla. Azolla filiculoides is under the sub-genus Euazolla. It is native to warm temperate and tropical regions as well as most of the old world including Asia, Australia and Anzali wetland. This plant is dark green to reddish and float on the water surface, either individually or in mats, which can reach a thickness of up to 20 cm. When A. filiculoides plants are exposed to strong sunlight they obtain a red color. The same occurs in winter time. In shade they always remain green. A. filiculoides settles in ponds, ditches, water reservoirs, wetlands, channels and slow flowing rivers. A. filiculoides is very rich in protein, fat, ash and carotenoids. The chemical composition of Azolla species varies with ecotypes and with the ecological conditions and the phase of growth. The dry matter percentage of different Azolla species varies widely. Lysine and methionine contents in this species are moderate. But, essential amino acids in this species are poor. Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms. Carotenoids are considered key molecules for life. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. Carotenoids as natural pigments, are used by the industry as pharmaceuticals, nutraceuticals, and animal feed additives, as well as colorants in cosmetics and special foods. Carotenoids have been studied for their ability to prevent chronic disease due to the free radical theory of aging in chronic disease etiology. The effect of carotenoids on biotechnology and the food industry is significantly attributed. Finally, carotenoids as fortified substances in foods and special aspects about carotenoids as health promoters are well presented along with a glance of carotenoids economics. β-carotene is one of the carotenoids. β-carotene is the main source of pro-vitamin A and is widely used as a food colorant. The majority of the β-carotene commercialized in the world is obtained by chemical synthesis from β-ionone. Therefore, research for the production of natural colors for use in food industry has particular importance.

    Aim

    The present project was aimed at determining the content, quality, and purity of β-carotene extracted from Azolla filiculoides in the Anzali Wetland, comparing it with synthetic β-carotene, and measuring its economic value.

    Methods

    One treatment had β-carotene derived from Azolla filiculoides in the Anzali Wetland through the alkaline hydrolysis method in the winter of 2014. Treatments were kept at 4 °C for one year. Synthetic β-carotene was used as the control. The quality of the treatments was assessed by applying some chemical tests, including the measurement of the content and quality of β-carotene, calorimetry using the Hunter-LAB method, determination of the purity and vitamin A employing high-performance liquid chromatography (HPLC), estimation of the dwell-time duration at 5 °C, and measurement of the solubility of β-carotene in water.

    Results

    The results of the tests regarding the purity, concentration, calorimetry, vitamin compounds, dwell time, and solubility in the experimental β-carotene, compared with those in the control, revealed no significant difference (p>0.05). Moreover, the factors showed no significant difference between the control and experimental treatments during the dwell time (p>0.05). The natural β-carotene had a good quality during the storage period at 5 °C for one year.

    Conclusion

    Since there was no significant difference between the β-carotene derived from Azolla filiculoides and the synthetic one in terms of the chemical tests, purity, and dwell time, and since the natural β -carotene derived from Azolla filiculoides takes precedence over the synthetic one in terms of the food hygiene, it is recommended that natural β-carotene extracted from Azolla filiculoides be substituted for synthetic β-carotene in the food industry.

    Keywords: Azolla, Natural pigment, β-carotene, Food additive, Anzali Wetland
  • Saber Amiri, Reza Rezaei Mokarram *, Mahmood Sowti Khiabani, Mahmoud Rezazade Bari, Mohammad Alizadeh Khaledabad Pages 33-49

    Lactic acid (2-hydroxyproponic acid) is an important organic acid with widespread applications in the food, pharmaceutical, detergent and agricultural industries. For this purpose, the effects of nutrients and important environmental factors on the production of lactic acid using the by-product of dairy plants (cheese whey and milk permeate) as a culture medium with pure culture of Lactobacillus acidophilus LA5 and Bifidobacterium animalis subsp. lactis BB12 were investigated. The results of statistical analysis of the data showed a significant effect of initial pH, incubation temperature, yeast extract concentration, type of culture medium and type of bacteria on lactic acid production (p <0.05). The incubation time, type of probiotic bacteria and yeast extract concentrations had a significant effect on cell density (p < 0.05). As well, the effect of initial pH, temperature and incubation time, yeast extract concentration, culture medium and probiotic bacteria on pH were significant (p < 0.05). Although the results of this study showed that milk permeate and cheese whey due to their high content of lactose can be a suitable medium for the production of lactic acid, the cost of using supplements, especially the nitrogen source, is essential.

    Keywords: Lactic acid, Cheese whey, Milk permeate, Lactobacillus acidophilus LA5, Bifidobacterium lactis BB12
  • Mohamad Reza Sayady, Zhaleh Khoshkhoo *, Ghorban Zarehgashti Pages 51-63

    The final price of the product is one of the major goals of the food industry and, in addition to product quality; the final price is also determinant to encourage consumers. For this reason, manufacturers try to pay special attention to these points, in this research, a combination of meat and beef has been used to obtain the ultimate quality and low final price. The reason for the use of Sea bream fish was due to its processing, availability and low cost. For this study, was used Brama fish minced due to good color, flavor and smell in medium weights 700-500 g. The color in the production of minced meat is one of the important factors and, therefore, the use of certain species of fish for the production of various products, accordingly, fish meat is divided into 3 groups: white, red and dark flesh, to make minced, meat of white flesh is usually used. According to all researchers and scientists, fish and its products have a high nutritional value, which is why it is recommended for all ages. In fish meat, and especially in marine fish, in addition to having easy digestibility proteins, unsaturated fatty acids are considered to be distinctive features. SFA saturated fatty acids and MUFA and PUFA unsaturated fatty acids have the best health benefits associated with unsaturated fatty acids of PUFA. In terms of quantity and quality, unsaturated fatty acids in marine fish are better than fish. Therefore, the quality of marine fish is better than farmed fish. For meat processing the fish were transferred to the processing center by icing, washing, dipping and filtration manually.Then it was washing again and mincing with 2 mm diameter cylindrical machine and 3 kg of freshly ground beef broth in 3 treatments and using 100% minced fish meat (treatment 1), 100% beef minced meat (treatment 2), combination of 50% fish and 50% beef minces (treatment 3) and finally treatment was packaged in polyethylene coatings, Store for 15 days at a refrigerator temperature of 4 ° C . Fatty acid and corrosive indices such as pH and fat oxidation (TBArs-Thiobarbituric acid) were evaluated. The results showed that regarding unsaturated fatty acids, Myristic and Palmitoleic in treatment 1 were significantly higher than other treatments , but the margaric and Euphoric in treatment 2 were higher (p < 0.05) and Eidateic acid (C18: 1) was the most abundant unsaturated fatty acid (MUFA) and was found to be higher than unsaturated fatty acids with multiple bonds (PUFAS) except linoleic acid, which significantly increased (p <0.05) , Other unsaturated fatty acids , Alpha-linolenic acid , Arachidonic acid, EPA and DHA in fish meat were significantly higher than other treatments (p <0.05) and linoleic acid was the most abundant unsaturated fatty acid of PUFAS .Significant results in this study have been the increase of unsaturated fatty acids in minced meat, and given that in red meat the amount of saturated fatty acids is higher than unsaturated fatty acids. Significant results in this study have been the increase of unsaturated fatty acids in minced meat, and given that in red meat the amount of saturated fatty acids is higher than unsaturated fatty acids. Measurement of sensory evaluation in food products is very important and has been considered in this research, in this study, indices such as taste, smell, color and texture were measured to measure sensory evaluation. The scoring tables have been used to measure each indicator, In this research, quantitative and qualitative research has been better in combining taste and market. Sensory evaluation results showed that treatments 3 (50% fish minced meat and 50% beef) had significantly higher sensory properties, such as color, taste and texture than other treatments (p < 0.05). Finally conclude that the treatment of 3 (combined meat of fish and beef) replacing beef with fish meat due to essential fatty acids in fish can improve nutritional value, as well as .It is recommended to use the minced meat as a combination of fish and red meat as the primary ingredient in the production of other food products such as burger or sausage. Which, in addition to innovation, causes diversity in production and reduces the final price of the product and also increases the quality and value added of food products. 

    Keywords: Sea bream, Indicators of corruption, Unsaturated fatty acids, Saturated fatty acids
  • Jaber Soleimani *, Mansoureh Mozaffari Pages 65-76
    Introduction

    The cultivar and amount of apricot production in the East Azarbaijan province is about 28% of the total country of Iran and 30.2% of the total apricot is produced in Iran. Due to the perishable nature of apricot, it cannot be kept for more than 2-3 days at room temperature and for several days at low temperature conditions. In Iran, about one-third of horticultural and crop products are lost and destroyed annually. Important factors in increasing postharvest losses of agricultural products can be inappropriately picked up, unpurchased shipping, lack of proper keeping and packaging, and so on. This research was carried out with the aim of developing research on apricot, as well as the development of its export, by increasing the shelf life of apricot. In food packaging, the use of appropriate packaging materials, and minimizing waste and the provision of healthier and safer food products have always been considered. Various packaged packaging technologies have been developed to improve the quality and health of foods. Active packaging technologies provide new opportunities for the food industry. In recent years, the effect of modified atmosphere has been studied on the physiological, biochemical and qualitative properties of fruits and vegetables. One of the physiological effects of modified atmospheres on fruit metabolism is the reduction of respiratory rate during storage, which includes a decrease in carbohydrate metabolism, CO2 production, O2 consumption, and heat release. In climacteric fruits such as apricots, the CO2-rich atmosphere and low O2 levels reduce ethylene production. Therefore, the use of MA can increase the length of storage time of fruits. High concentrations of CO2 are effective in O2 consumption. They act as inhibitors of ethylene activity and prevent ethylene synthesis in some fruits such as apricots, avocados, pears, figs and bananas.

    Materials and methods

    the study focused on reduce the production of ethylene and increase the shelf life of apricot fruit by studying the modified atmosphere packaging technology. In this project, apricot fruits of “Red Shahroud” cultivar were obtained from “Sahand Gardening Research Station of East Azarbaijan Agricultural and Natural Resources Research Center”. Packaging film of polypropylene was prepared for packing apricot fruits with 0.2 and 0.4 mm thickness from a local store. For gas injection operations, capsules containing oxygen and carbon dioxide gases (food grade) were used. The packets space were first with vacant evacuated, and then gases injected. After the gas was injected, the packages were stored in the refrigerator at a temperature of 1°C (±0.5) and cold air temperatures were kept at about 1 m/s, and every four days, tests were completed that lasted a total of 16 days. The evaluated parameters in this study were TSS, pH, firmness and EC. The MC-20181 model refract meter was used to measure TSS. For pH test, the pH meter of the metrohm-691 model was used. The texture analyser of Hounsfield-H5KS was used to measure the firmness of the apricot fruit. The EC meter ELMETRON CC 505 with an accuracy of 0.1 was used to measure EC. The experimental design was a split plot based on a completely randomized design including two plots and three replications. The main plot consisted of time in four levels (fourth day, eighth day, twelfth day, and sixteenth day). Sub plots was include the type of gas mixture used with different coatings in six levels (3% O2 + 5% CO2 with polypropylene film thickness 0.2 mm, 3% O2 + 10% CO2 with polypropylene film thickness 0.2 mm, 3% O2 + 5% CO2 with polypropylene film thickness 0.4 mm, 3% O2 + 10% CO2 with polypropylene film thickness 0.4 mm, Packaging only with polypropylene cover with thickness of 0.2 mm, Packaging only with polypropylene cover with thickness of 0.4 mm).

    Results and discussion

    by increasing the storage time, the TSS was increasing. The highest amount of TSS on the 16th day was observed in polypropylene wrap with 0.2 and 0.4 mm thickness without gas composition. TSS represents the presence of small molecules such as glucose, fructose, maltose and some organic acids. By increasing the storage time of fruits, the TSS values will be increased due to the large conversion of molecules such as starch into small molecules such as glucose, maltose and dextrin, as well as reducing the moisture content of the product. On the other hand, due to reduced physiological activity of the fruit at low temperatures, the trend of the TSS will slow down. With increasing storage time, pH increased as a result of the decreasing trend of acidity. Organic acids can be considered as a source of energy stored in fruits, which decrease as a result of increased metabolism activity due to respiration or conversion to sugars. Treatment with only 0.2 mm thick PP coating showed the most effect on apricot fruit acidity, and the rest of the treatments showed an almost identical effect on acidity reduction. The treatment of 3% O2 + 10% CO2 under the cover of PP with a thickness of 0.4 mm showed the highest acidity. With increasing maintenance time, the firmness shows a downward trend. Treatment with 3% O2 + 10% CO2 covered by PP with thickness of 0.4 mm resulted in the highest firmness in apricot fruit compared to other treatments and the least firmness in non-gaseous treatment and only with a thickness of 0.2 mm was observed. With increasing storage time, the EC value also increased, but the effect of different gas constituents with different coatings and the time interaction effect with different gas mixtures with different coatings is not significant. EC shows variations in the resistance or electrical capacity that occurs as a result of changes in the concentration of soluble electrolytes when they are matured in flesh. The EC increases during fruit ripening. The incremental trend of EC extract of fruit during storage is indicative of cation leakage from the cytoplasmic membrane of fruit tissue cells, which shows the degradation of the cell membrane. This process is attributed to the ability of the pectin’s to dissolve and hydrolyse the median wall of the cell. The activity of the polygalacturonase enzyme leads to cell wall pectin hydrolysis, which seems to provide the ability to dissolve the pectin. While the pectin methyl ester enzyme regulates the attachment of cations to the cell wall and the rapid action of other cell wall hydrolysates. Therefore, cations play a key role in enzymatic activity and fruit maturity regulation.

    Conclusion

    the results showed that with increasing the of storage time, all the traits under test, namely, TSS, pH and EC, increased and fruit firmness decreased. From the point of view of the treatments used, the of type of gas mixture with different films, 3% O2 + 10% CO2 with polypropylene film thickness 0.4 mm treatments is desirable because of increased shelf life of apricot approximately 3 times. Film thickness did not significantly affect the shelf life of apricot fruit.

    Keywords: apricot, Modified atmosphere, Oxygen, Carbon dioxide
  • Akram Sharifi *, Nasim Pour Ebrahim, Maryam Maleki, Nasim Divandari Pages 77-87

    Effect of temperature, xanthan and guar hydrocolloids on rheological properties of salsa sauce Abstract Salsa is one of the most popular and widely used tomato sauces that contains tomato, onion, garlic, pepper, salt, herbs, spices, and acid. In this study, some physicochemical characteristics of salsa such as acidity, total sugar, salt, total soluble solids, pH, total ash, and rheological parameters are measured using a Brookfield viscometer at temperatures of 5, 25 and 45 ° C and at three different levels of xanthan and guar (xanthan 100%, guar 100% and xanthan 50%-guar 50%). Using Mitschka method, the results show that salsa has a non-Newtonian behavior characterized by the power law model. Flow behavior index (n) and consistency consistency coefficient(k) for all of samples was (0.282-0.378) and (1.91-3.12) respectively.The flow behavior index, n was<1, that represents the dilute or pseudoplastic behavior of salsa sauce samples. The flow behavior index (n) and consistency coefficient (k) decreased with increases in temperature. The effect of temperature was identified by Arrhenius equation and the activation energy of 3.2135 to 10.947 KJ/mol was determined. The salsa sauce containing Guar and xanthan had the least energy activation, and then the sauce contains 100% xanthan, this sauce had the highest amount of consistency coefficient in temperature of 5° C. Therefore, it has more appropriate rheological properties than other samples. Key words: salsa sauce, Guar, Xanthan, Mitschka method, Rheological properties. Salsa is one of the most popular and widely used tomato sauces that contains tomato, onion, garlic, pepper, salt, herbs, spices, and acid. In this study, some physicochemical characteristics of salsa such as acidity, total sugar, salt, total soluble solids, pH, total ash, and rheological parameters are measured using a Brookfield viscometer at temperatures of 5, 25 and 45 ° C and at three different levels of xanthan and guar (xanthan 100%, guar 100% and xanthan 50%-guar 50%). Using Mitschka method, the results show that salsa has a non-Newtonian behavior characterized by the power law model. Flow behavior index (n) and consistency consistency coefficient(k) for all of samples was (0.282-0.378) and (1.91-3.12) respectively.The flow behavior index, n was<1, that represents the dilute or pseudoplastic behavior of salsa sauce samples. The flow behavior index (n) and consistency coefficient (k) decreased with increases in temperature. The effect of temperature was identified by Arrhenius equation and the activation energy of 3.2135 to 10.947 KJ/mol was determined. The salsa sauce containing Guar and xanthan had the least energy activation, and then the sauce contains 100% xanthan, this sauce had the highest amount of consistency coefficient in temperature of 5° C. Therefore, it has more appropriate rheological properties than other samples. Key words: salsa sauce, Guar, Xanthan, Mitschka method, Rheological properties. Salsa is one of the most popular and widely used tomato sauces that contains tomato, onion, garlic, pepper, salt, herbs, spices, and acid. In this study, some physicochemical characteristics of salsa such as acidity, total sugar, salt, total soluble solids, pH, total ash, and rheological parameters are measured using a Brookfield viscometer at temperatures of 5, 25 and 45 ° C and at three different levels of xanthan and guar (xanthan 100%, guar 100% and xanthan 50%-guar 50%). Using Mitschka method, the results show that salsa has a non-Newtonian behavior characterized by the power law model. Flow behavior index (n) and consistency consistency coefficient(k) for all of samples was (0.282-0.378) and (1.91-3.12) respectively.The flow behavior index, n was<1, that represents the dilute or pseudoplastic behavior of salsa sauce samples. The flow behavior index (n) and consistency coefficient (k) decreased with increases in temperature. The effect of temperature was identified by Arrhenius equation and the activation energy of 3.2135 to 10.947 KJ/mol was determined. The salsa sauce containing Guar and xanthan had the least energy activation, and then the sauce contains 100% xanthan, this sauce had the highest amount of consistency coefficient in temperature of 5° C. Therefore, it has more appropriate rheological properties than other samples. Key words: salsa sauce, Guar, Xanthan, Mitschka method, Rheological properties. Salsa is one of the most popular and widely used tomato sauces that contains tomato, onion, garlic, pepper, salt, herbs, spices, and acid. In this study, some physicochemical characteristics of salsa such as acidity, total sugar, salt, total soluble solids, pH, total ash, and rheological parameters are measured using a Brookfield viscometer at temperatures of 5, 25 and 45 ° C and at three different levels of xanthan and guar (xanthan 100%, guar 100% and xanthan 50%-guar 50%). Using Mitschka method, the results show that salsa has a non-Newtonian behavior characterized by the power law model. Flow behavior index (n) and consistency consistency coefficient(k) for all of samples was (0.282-0.378) and (1.91-3.12) respectively.The flow behavior index, n was<1, that represents the dilute or pseudoplastic behavior of salsa sauce samples. The flow behavior index (n) and consistency coefficient (k) decreased with increases in temperature. The effect of temperature was identified by Arrhenius equation and the activation energy of 3.2135 to 10.947 KJ/mol was determined. The salsa sauce containing Guar and xanthan had the least energy activation, and then the sauce contains 100% xanthan, this sauce had the highest amount of consistency coefficient in temperature of 5° C. Therefore, it has more appropriate rheological properties than other samples. 

    Keywords: salsa sauce, Guar, Xanthan, Mitschka method, consistency coefficient
  • Azadeh Shahsavna Tabrizi, Esmaeil Ataye Salehi *, Zahra Sheikholeslami Pages 89-105

    The main problems of bread that increased by reducing flour extraction efficiency are the loss of sensory properties especially color, texture features and accelerating staling rate mainly due to the low fiber content by reduction or elimination bran of flour. The use of alternative fiber sources such as soybean flours that lipoxygenase enzyme is active, which is one of the best ways to naturally enrich, improve quality, and reducing staling. Soy flour, derived from ground soybeans, boosts protein, brings moisture to baked goods, and provides the basis for some soymilks and textured vegetable protein. Adding soy flour to baking products increases the yield of dough, improves the quality of the product and improves the properties of texture, taste and enhancement of the quantity and quality of the protein and acts as an emulsion. So the effect of replacing soybean flour on three levels of 4 %, 8 % and 12 % with wheat flour on qualitative and sensory properties, staling and color of bread on a completely randomized design were investigated. Specific volumes were measured by rapeseed two hours after baking. The crust color analysis was carried out by determining three indices L *, a * and b * in the time interval 2 hours after cooking according to San method, and as well as The brian color analysis was carried out by determining three indices L *, a * and b * in the time interval 2 hours after cooking according to San method. In order to assess crumb porosity of between 2 hours after cooking method Haralyk was used. The bread tissue was evaluated 2 and 48 hours after baking using a tissue weighing machine 1 (CNS Farnell model, ertfordshire UK) based on Pour Farzad method. For sensory evaluation, a 5-point hedonistic scoring method was used, in which characteristics such as shell color, appearance of the skin, texture (ductility or unusual softness, stiffness of the bread, crispness and fragility), aroma, taste, flavor and odor and overall appearance and in The total acceptance is based on the total score of the parameters of the color of the brain, the color of the skin and the appearance of the skin and the appearance of the public within 2 hours after the bread is baked. Also, for sensory evaluation, the sensory evaluation for staling was used according to AACC 11-38 at 24 and 48 hours after baking. The results clearly showed that increasing the percentage of active soybean meal increases the L * bread component, delaying the bread staling, the highest amount L * crust of the sample with 12 % of soy flour was equal to 72 and the lowest in the control sample was 61. With an increase in the percentage of soy flour, has been reduced the component a * bread brains and a * bread crust and as well as with an increase in the percentage of soy flour, increased the component b * bread brains and b * bread crust, as well as with increasing the amount of soy flour, the porosity of the control sample was significantly decreased. As the increased percentage of soybean, decreased the specific volume of bread, adding more than 4 % soy flour had a negative effect on the bread volume. The addition of 4 % of soybean flour has no significant effect on stiffness, but adding more than 4 % in both times cause increase this parameter. The least stiffness was observed in the control treatment at 2 and 48 hours after baking, which was not significant with 4 % active soybean flour. The highest rigidity was observed in the treatment containing 12 % active soybean flour. The increase in the percentage of soybean flour has slowed the staling process at 24 and 48 hours after cooking. Adding soy flour increases the absorption of dough water and, as a result of preserve more moisture, its mechanical properties improve. The results showed the color of bread improved by increasing the amount of soybean flour and retards the staling but increasing more than 4 % soy flour in bread formulation reduced tissue, flavor, odor and overall appearance. Use of soybean flour as a substitute for wheat flour in pan bread improves the quantitative and qualitative characteristics of the final product and therefore, reduces waste.

    Keywords: Activated soybean flour, Color, Pan bread, Staling, Texture
  • Akram Pezeshky *, Maryam Khakbaz Heshmati, Zahra Abutalebi Pages 107-121

    Due to unsaturated fatty acids of GSO, is exposed to various types of chemical reactions, including enzymatic reactions and lipid oxidation. In this regard, the use of antioxidants for increasment the resistance of the oil to oxidation, is essential. Due to the poor nutritional and cancerous effects of these compounds and the consumer's desire to use natural compounds, the use of natural antioxidants is considered by researchers instead of industrial antioxidants. Spices (ginger, pepper, cinnamon, cardamom, thyme) and aromatic vegetables such as basil and peppermint with essential oils (EOS) containing multiple polyphenols with anti-oxidant and anti-microbial properties are a good source of natrul antioxidant (Teixeira et al., 2013; Srinivasan, 2017). Ginger is an important medicinal herb and has several properties, including anti-nausea, cardiovascular, antibacterial, liver anti-inflammatory, lowering blood cholesterol stimulates brain circulation and stimulates digestion. The presence of antioxidants in ginger causes the removment of free radicals from oil. Thyme is the other valuable herbs with high antioxidant and antimicrobial activity and is one of the world's best herbs in terms of high levels of antioxidants. The phenolic antioxidants in thyme, eliminate free radicals and prevent oxidative stress in all body systems. In spite of studies on the use of phenolic compounds in oxidation stability of oils, the use of ginger and thyme EOS in combination, as a natural antioxidant has not been investigated for the stability of grape seed oil. By extracting these phenolic compounds and adding to grape seed oil, it can be expected that the oleoresin in these plant extracts, in comparison to industrial antioxidants, increases the oxidative stability of grape seed oil. Methods Extraction of phenolic compounds from ginger and thyme 25 g of powdered ginger or thyme was placed in a cellulose ring of suksele apparatus. Then their phenolic compounds were extracted using methanol solvent. Extraction was done at a temperature higher than boiling point of solvent (65 °C) and continued until extraction complete. The solvent was removed using a rotary evaporator and the extracted compounds was stored for further experiments in the refrigerator (Seidi Damyeh and Niakousari, 2015). Different types and concentrations of metanoic extraction were added to GSO (Table 1) and experiments was done during 45 days of storage. Table 1 Number Timar 1 Control sample (grape seed oil without antioxidant) 2 GSO+ α-tocopherol (200 ppm) 3 GSO+ ginger phenolic compounds (300 ppm) 4 GSO+ thyme phenolic compounds (300 ppm) 5 GSO+(ginger+thyme) phenolic compounds (300 ppm) Experiments The properties of sunflower oil including acidity, peroxide and tiobarbioturic acid (TBA) indices, total phenol and antioxidant activity were studied during 45 days of storage. Statistical Analysis The results were analyzed using completely randomized blocks during 45 days of the storage time. One-way ANOVA and Duncan’s mean comparison tests were used at 5% significance (p < 0.05). Results and discussions Acidity acidity of the all samples increased significantly during the 45 days of storage (p < 0.05). The sample contained 300 ppm of (thyme and ginger) phenolic compounds on the 45th day had the lowest acidity and the highest acidity was observed in the sample without antioxidants (control sample). GSO containing two species of thyme and ginger had fewer amounts of FFA and were able to prevent oxidation, resulting in less acidity, Peroxide index The rate of peroxide index increased significantly during the 45 days of storage. In all days, the control sample had the highest amount of peroxide because the presence of antioxidants in different samples caused the peroxide to be neutralized and consequently reduced its amount and against the lowest index after 45 days of the sample. TBA index In all samples, the level of TBA index increased significantly, while the lowest amount of the index after 45 days of storage was related to the sample containing α-tocopherol and the sample containing 300 ppm of thyme metanoic extraction. It should also be noted that no significant difference was found between them. In the case of other treatments, it can be stated that the highest level of this index is related to the control sample without any antioxidants. TBA index shows the amount of secondary oxidation products, especially aldehydes. Total phenol Over time, Total phenol (mg of gallic acid per liter) of oil samples containing different concentrations of antioxidants has been significantly reduced in all samples. According to the results, it can be stated that with increasing concentrations of phenolic compounds in oil samples, the total phenol content also increased. This can be attributed to the presence of phenolic compounds in both essential oils of thyme and ginger. Phenolic compounds play an essential role in antioxidant activity due to the presence of hydroxyl groups in their structure and their ability to donate hydrogen to the free radicals. Conclusion The results showed acidity of the samples increased during storage. Peroxide value and TBA of sunflower oil samples were significantly increased during storage. The lowest amount of these indices after 45 days was related to the samples containing α-tocopherol and 300 ppm mixture of ginger and thyme, respectively. The total phenol also was increased by increasing the concentration of extract which can be due to the presence of phenolic compounds in the ginger and thyme extracts. The radical scavenging activity of all samples was decreased during storage. The highest antioxidant activity was related to the samples containing α-tocopherol and then those containing 300 ppm of ginger +thyme extract In general, it can be concluded that the metanoic extraction of ginger and thyme can be used as a natural antioxidants in the edible oils to prevent their oxidation.

    Keywords: sunflower oil, thyme, ginger, oxidative stability, Antioxidant Activity
  • Davood Ataei, Hassan Ahmadi Gavlighi Pages 123-135

    The xylan of date kernel variety KabKab, was extracted and then was hydrolyzed by two commercial xylanases called Pentopan mono BG and Veron 191. The xylooligosaccharides (XOS) in the two hydrolyzates were qualified and quantified by HPAEC-PAD. In order to testing digestibility of the XOS, the hydrolyzates were exposed to the solutions similar gastric juices. Results showed that the XOS are resistand to digestion. Effect of the XOS, as carbon source, on growth of Bifidobacterium Bifidum, Compared with other carbon sources, was determind too. The results showed that maximum growth rate and optical density at time 24 houre (OD24) for the two XOS have a significant difference with two other carbon source and control but no significant difference was observed between the two XOS at 95% possibility. pH of cultures at interval times were determined. Decrease of pH for XOS was more, that indicates more organic acid production. Overall, due to indigestibility of these XOS and their positive effect on Bifidobacterium bifidum, prebiotic property potential can attribute to them.

    Keywords: Probiotic, Prebiotic, Xylooligosaccharide, Date kernel, Digestibility
  • Davood Mazidi, Seyyed Hossein Hosseini Ghaboos * Pages 137-149

    Due to environmental problems caused by the use of artificial films, researchers have begun to produce natural edible coatings for the preservation of food, including fruits and vegetables, and one of the sources of their preparation is plant gum. This research was carried out to investigate the effects of Balangu and Basil seeds gum coating on storage life and some quantitative and qualitative properties of peach during cold storage. For this purpose a factorial experiment in a completely randomized design with three replications was conducted separately for fruit. Each experiment consisted two factors including treatments and storage time. Treatments were applied with dipping of fruits for 5 minutes in prepared solution at 25˚C. After drying, the fruits were packed in plastic containers and stored in cold storage at 5˚C and 90% RH. Second factor was storage time with 4 levels including 1 (beginning of storage), 10, 20 and 30 days after storage. In each of the mentioned dates the fruits were removed from storage and the following quantitative and qualitative parameters were evaluated: soluble solids, titratable acidity, ethylene production, respiration rate, total phenols and sensorial evaluation. The results showed that application of Balangu and Basil seeds gums had a significant effect on reducing respiration rate of peach. The effect of storage time on all evaluated traits in peaches were significant. At the end of storage, the soluble solids and phenols in fruit were increased, and titratable acidity decreased. According to the results, the use of 0.1% Balangu and Basil seeds gums is recommendable as a natural edible coating to preserving quality and extending storage life of peaches.

    Keywords: Balangu seed gum, Basil seed gum, Ethylene, peach, Respiration
  • Somayeh Solaimani Mehr, Zaynab Raftani Amiri *, Reza Esmaeilzadeh Kenari, Ehsan Sadeghi Pages 151-167
    Introduction

    The use of pesticides has increased considerably for crop production in recent years. Despite advantageous properties of pesticides for controlling different pests and preventing diseases, they have many negative effects on humans and environment. Different methods have been proposed to reduce the effects of pesticides on fresh and dried foods, including washing, storage, peeling, heating, boiling, frying and bleaching, canning, freezing, etc, but they don't have enough ability in this regard (Ali Mohammadi and Jihadi 2014). For these reasons, efficient and novel methods such as microwave irradiation have received great attention to decrease residues of pesticides in vegetables and fruits. Reducing their residues can be effective in improving the quality of foods and human health (Guillet et al 2009, Kaushik et al 2016). Iran is the third largest producer of apricot in the world. Dried apricot has many nutritional and health benefits and is considered as healthy choice (Wani et al. 2017). In the present study, effect of microwave irradiation was evaluated on residues of Orthocide (trade name: captan) pesticide and physicochemical properties of dried apricots during storage.

    Materials and methods

    Apricot fruits (Nasiri variety) were provided by agricultural jihad organization of Kermanshah province and were dried (Hussain et al. 2010). Then, Orthocide (trade name: captan) pesticide in three levels of 25, 50 and 75 ppb (μg/ kg) were inoculated to organic dried apricots. In the next stage, inoculated samples were subjected to microwave irradiation (2.5 and 5 min) and pesticide residues were determined after irradiation during two months of storage (Cieslik et al. 2011, Seid Mohammadi et al. 2012). Also, a series of samples without any pesticide inoculation were irradiated with microwave (2.5 and 5 min) and were evaluated in terms of ash content (AOAC 2005, 940.26), moisture content (AOAC 2005, 934.06), total phenolic content (Arabshahi and Urooj 2007), reducing sugar content (AOAC, 2005, 925.36), total microbial count, mold and yeast counts (Rahman et al. 2011), color (parameters of L*, b* and a*) (Basaran and Akhan 2010) and antioxidant activity (Arabshahi and Urooj 2007) in different storage times (0, 30 and 60 days). Obtained data were analyzed by repeated measure design and factorial design using analysis of variance (ANOVA) and least square means in significance level of 0.05 (p < 0.05).

    Results and discussion

    The results showed that microwave irradiation caused a significant decrease in pesticide residues of dried apricot in all levels of pesticide inoculation (5.05-26.07 %) compared to control sample. This reduction can be attributed to existence hot spots and non-thermal effects of microwave (Sajjadi et al. 2016). In addition, increase of storage time had significant effect on reduction of pesticide residues (p < 0.05). Overall, the highest reduction amount in pesticide residues (26.07 %) was related to samples treated with microwave radiation for 5 min at zero time (Table 2). In accordance with our results, residue of cypermethrin pesticide in brinjal reduced after processing with microwave (Walia et al. 2010). Microwave radiation also led to an increase in the content of phenolic compounds and antioxidant activity (Figures 2 and 3) which may be associated with breakdown of covalent bonds between phenolic compounds and other components (such as protein and sugar) by microwave, increasing extraction efficiency of phenolic compounds and therefore antioxidant activity (Hayat et al. 2010a). Similar results have been reported by Igual et al (2010). Moreover, ash and reducing sugar contents of samples increased by microwave but a significant decrease was observed in the moisture content of dried apricot (p < 0.05). Microwave radiation could significantly diminish total microbial count and mold and yeast counts compared to control sample. This can be justified by thermal and non-thermal effects of microwave on microorganisms (Heddleson and doores 1994, Kozempel et al. 1998). The lowest microbial count (2.39 log CFU/g) was related to samples treated with microwave for 5 min at zero time. Similarly, microbial load of saffron samples decreased after microwave irradiation (Hosseini Nejad et al. 2003). Also, irradiation with microwave led to a decrease in L* factor and an increase in a* (redness) and b* (yellowness) factors of samples (p < 0.05). The least color changes were found in samples irradiated with microwave for 2.5 min (Table 5). Color changes can be attributed to the degradation of vitamin C, carotenoids and other pigments due to heating effect of microwave and environmental factors. Also, loss in moisture content may be effective in making these changes. Similar results have been reported by Jogihalli et al (2017) for chickpea.

    Conclusion

    Microwave irradiation for 5 min resulted in more changes in determined parameters in comparison with 2.5 min of irradiation time and was more effective in reducing pesticide residues of dried apricot. Therefore, microwave irradiation can be considered as appropriate and promising way to decrease pesticides residues in fruits and vegetables.

    Keywords: Antioxidant Activity, Dried apricot, Microwave radiation, Pesticide residue, Storage time
  • Sima Mohajer Khorasani, Mehran Alami *, Mehdi Kashanineghad, Hoda Shahiri Tabarestani Pages 169-187
    Introduction

    Today, the most common way to increase the quality of gluten-free products is to use gum. According to recent studies, physical modification techniques such as microwave treatment can be used to improve the functional properties of flour and gluten-free baking products.

    Material and methods

    Therefore, in order to compare the effect of xanthan gum and microwave treatment of millet grain on physicochemical and sensory properties of gluten cake (obtained from millet and rice flour with 50:50), xanthan gum was used at two different levels of 0 and 0.15% and microwave treatment was applied at three levels of moisture 10, 15 and 20% and times 60, 30 and 90 s with a constant microwave power of 900 W.

    Results and discussion

    According to the results, the use of the microwave treatment of millet grain reduced the specific gravity and increased viscosity of gluten-free cake batter (p < 0.05). The cake samples prepared from the microwave treated grain with 20% moisture content at 90 or 60 s showed the highest volume, porosity, and sensory acceptance. Moreover the softest texture and the highest moisture content during storage belonged to the sample preparedwith flour from the microwave treated grain under 20% and 90s.

    Conclusion

    According to the results of this study, microwave treatment of millet grain could be a good alternative to using gum in a gluten-free cake.

    Keywords: Gluten free cake, Millet, Rice, Microwave treatment, Xanthan gum
  • Khadijeh Ababaf, Hossein Jooyandeh *, Behzad Nasehi Pages 189-201
    Introduction

    The word “probiotic” comes from the Greek word “pro bios” meaning “for life”, which is the opposed of the term “antibiotics” meaning “against life.” Probiotics are alive bacteria and the majority of probiotic microorganisms are belonging to the genera of Lactobacillus and Bifidobacterium. Regular consumption of probiotics in the adequate amounts have many beneficial health such as prevention of diarrhea, constipation, intestinal diseases and help to digest lactose and strengthen the immune system. On the other hand, recently the use of soy products has been progressively increased due to consumer consciousness about soy benefits. Soy probiotic yogurt is of special importance due to the presence of functional compounds such as probiotic microorganisms and natural prebiotics (raffinose, stachyose), the combination which is considered and dubbed as synbiotic. Dairy products, especially probiotic yogurt, are the most common foods that are used as probiotic products. On the other hand, yogurt production and similar products have always been accompanied with problems such as defects in texture, structure and syneresis. The functionality and structure of proteins can be modified with physical, chemical and enzymatic procedures. Enzymatic modification has been recommended as a useful technique owing to high specificity of enzymatic reactions and therefore a little risk of formation of toxic products. Transglutaminase enzyme can produce a gel with a desirable structure by forming covalent bonds between glutamine and lysine in protein systems. Therefore, the effect of application of transglutaminase enzyme in protein food systems (such as milk, yogurt, cheese, ice cream, bread, fish, meat and other food products) have been extensively studied by many researchers. So, the aim of this study was to evaluate the physicochemical and microbial properties of symbiotic soy yogurt as affected by TG-enzymatic treatment at different inulin concentrations.

    Materials and methods

    The effect of different amounts of TG-enzyme (0, 0.015, 0.03 and 0.045%) and inulin (0, 1 and 2%) on physicochemical (pH, acidity, syneresis) and microbial characteristics (probiotic count) of synbiotic soy yogurt during 21 days of cold storage (1, 7, 14 and 21 days) was investigated. To prepare the synbiotic soy yoghurt samples, inulin as a prebiotic and Lactobacillus acidophilus and Bifidobacterium lactis as probiotic bacteria were used and added to the soy milk. After addition of inulin, soy milk was heated (95 °C for 5 min) and cooled to inoculation temperature (45 °C). After the enzyme addition, the probiotic starter culture was added and fermentation was done at 42 °C until the pH was reached to 4.6. Sample without TG-enzyme and inulin was considered as control yogurt. For performing analysis, data were analyzed by a completely randomized factorial design using SPSS software, version 24. The mean of treatments was compared with Duncan test at 95% confidence level.

    Results and discussion

    The results showed that with increasing the enzyme concentration, amount of acidity and syneresis decreased while pH increased significantly (p < 0.001). This was probably due to formation of internal and interstitial bonds in protein network which causes reduction of bioavailability of organic compounds for microorganisms (reduce acidity) and increases water holding capacity (reduce syneresis). However, enzymatic treatment had no significant effect on total solids of the samples. Increasing the amount of inulin also caused a significant increase in acidity and total solids while expressively reduced pH and syneresis of yoghurt samples (p < 0.001). The reduction of syneresis as a consequence of inulin addition was probably due to water absorption and water holding capacity of this compound. The highest total solids was recorded for yogurt sample containing 2 percent inulin and the lowest was recorded for control (0 percent inulin). By passing the time of storage, pH and syneresis significantly decreased and acidity until the fourteenth day increased and thereafter decreased considerably (p < 0.001). However, there was no significant effect on the amount total solids. The results of microbial analysis showed that with increasing enzyme concentration, the survival amount of Bifidobacterium lactis decreased significantly (p < 0/01). Although their number in the sample containing the highest level of enzyme was higher than standard. The formation of covalent bonds due to the addition of the TG enzyme can remove lower the molecular weight of peptides from the available microorganisms and thus reduce their growth. On the other hand, by increasing the enzyme concentration, unlike Bifidobacterium, the survival rate of Lactobacillus acidophilus increased significantly compared to the control sample, but eventually the amount was lower than the standard. By increasing the inulin concentration at level 2% the growth rate of Bifidobacterium lactis was significantly increased (p < 0/01). The effect of storage period on the survival rate of Bifidobacterium showed that during storage, their number decreased significantly (p < 0/05). However, the number of probiotic bacteria in all soy synbiotic yogurts at the end of 21-day maintenance were over 107 logcfu/g. Our results also showed significant interactions between three tested variables on the physicochemical characteristics and the probiotic counts.

    Conclusion

    In general, the results of this study showed that the addition of enzyme and inulin during storage period did not have an adverse effect on pH and acidity and also reduced the syneresis. The sample containing 0.045% enzyme and 2% inulin at the end of the storage period showed the least syneresis compared to the control sample. In this study, amongst two probiotic bacteria, Bifidobacterium lactis, in comparison with Lactobacillus acidophilus, was able to maintain its survival rate above the standard level. Among the different samples, the sample containing 2% inulin on the first day of storage period had the highest probiotic content. According to the results, the best synbiotic soy yogurt with acceptable probiotic count and physicochemical properties could be produced using 2% inulin and 0.015% TG-enzyme concentration.

    Keywords: Transglutaminase enzyme, Soy yogurt, Inulin, Probiotic, Functional products
  • JAVAD PARSA *, Mohammad Ismaeil Amiri, Jafar Hajilou, Farhang Razavi, Hamid Rahnemon Pages 203-219
     Introduction 

    Apricot fruit is a carbohydrate-rich commodity and is a good source of fibers, essential minerals, vitamins and organic acids. It is also rich in bioactive compounds i.e. polyphenols and carotenoids that have certain antioxidant character in biological system. It is consumed in fresh, dried and frozen forms or used for the preparation of jam, juices, nectars and extruded products. Therefore, apricot being an attractive nutritious fruit is appreciated by consumers and farmers all over the world and has gained great economic importance over the years. Apricot is a climacteric fruit that presents a high respiratory and metabolic rate and, among stone fruits, is the one that presents the highest ethylene emission. One of the major problems of apricots is the rapid postharvest softening, which limits its storability and marketability. These features results that, at the postharvest, have an extremely short shelf-life of only 1-2 weeks in the cold storage, and pass quickly from maturity to overripe. One of the major problems of apricots is the rapid postharvest softening, which limits its storability and marketability. For this reason, to have acceptable quality fruits, they must be stored with adequate techniques to limit the post-harvest losses. As apricot production and export increase, demands for practical methods of post-harvest quality retention are necessary to improve the post-harvest quality of apricots during postharvest life. Several pre- and postharvest technologies have been used to control postharvest losses, but the use of chemicals as fungicides is restricted in most countries and consumers demand agricultural commodities without pesticide residues. Consumers around the world demand for food of high-quality, without chemical preservatives, and extended shelf life. Therefore, an increased effort has been made to develop new natural preservatives and antimicrobials. Many storage techniques have been developed to extend the marketing distances and holding periods for commodities after harvest. Among these technologies, edible coatings are traditionally used to improve food appearance and preservation. Edible coatings are thin layers of edible material applied to the product surface in addition to or as a replacement for natural protective waxy coatings and provide a barrier to moisture, oxygen and solute movement. They are applied directly on the food surface by dipping, spraying or brushing. Edible coatings are used to create a modified atmosphere and to reduce weight loss during transport and storage. In fact, the barrier characteristics of gas exchange for films and coatings are the subjects of much recent interest. Recently, researchers have developed a gel based on Aloe vera that prolongs the conservation of fresh fruits. This gel is tasteless, colorless and odorless. This natural product is a safe and environmental friendly alternative to synthetic preservatives such as sulfur dioxide. This gel operates through a combination of mechanics, forming a protective layer against the oxygen and moisture of the air and inhibiting the action of micro-organisms that cause food-borne illnesses through its various antibacterial and antifungal compounds. Aloe vera gel-based edible coatings have been shown to prevent moisture and firmness losses, control respiratory rate and delay ripening process slow oxidative browning and reduce microorganism proliferation in fruits. Present study was conducted to evaluate the increasing of apricot storage time, introducing suitable cultivars based on Aloe vera gel coating, effects of Aloe vera gel on the qualitative characteristics of fruit and obtain the optimum concentration of Aloe vera gel required to coating apricot fruits.

    Material and methods

    Therefore, a factorial experiment was carried out based on a completely randomized design with four replications. The evaluated factors including cultivars “Dorosht-e Malayer” and “Ghermez-e Shahrood”, concentrations of Aloe vera gel [control (non-gel coating fruits), 25% and 33%] and storage time [0 (Harvest), 7, 14 and 21 d)]. Moreover, total soluble solids (TSS), titratable acidity (TA), fruit firmness, pH, percentage of weight loss, antioxidant activity and vitamin C content were determined during storage time.

    Results

    The results showed that treatment of apricot fruits with Aloe vera gel, especially at 33% concentration, significantly enhanced vitamin C content, titrable acidity, antioxidant capacity and improved tissue firmness, but also reduced soluble solids, weight loss and pH content. Moreover, it was found that vitamin C content, titratable acidity and fruit tissue firmness significantly decreased during storage time, while soluble solids content, weight loss and antioxidant capacity significantly increased. Among the cultivars, “Ghermez-e Shahrood” cultivar had higher soluble solids content, weight loss, pH and antioxidant capacity during storage time, whereas “Dorosht-e Malayer” cultivar had higher titrable acidity, tissue firmness and vitamin C at the end of storage time. double and triple interaction effects of evaluated factors significantly affected all characteristics, except in antioxidant activity, where just storage time had a significant effect. It was found that the highest vitamin C content in “Dorosht-e Malayer” and “Ghermez-e Shahrood” was obtained at the end of the second week in coated fruits with 33% of Aloe vera gel. TSS content in fruits of “Dorosht-e Malayer” cultivar that coated with 25% and 33% of Aloe vera gel was less than “Ghermez-e Shahrood” cultivar, while Aloe vera gel had no significant effect on TSS content in “Ghermez-e Shahrood” cultivar. Aloe vera gel had no defined pattern on TA concentration but generally, “Dorosht-e Malayer” fruits had higher TA concentration comparing “Ghermez-e Shahrood” fruits During the storage time, the fruit weight loss and firmness were higher in “Ghermez-e Shahrood” as compared with “Dorosht-e Malayer”, however, in the both evaluated cultivars, treatment with Aloe vera gel had a significant positive effect to controlling of fruit weight loss and firmness. Furthermore, coating with Aloe vera gel improved the antioxidant capacity in both evaluated cultivars.

    Conclusion

    Overall, according to the results, it can be concluded that as compared with “Ghermez-e Shahrood” cultivar, “Dorosht-e Malayer” cultivar showed better quality based on the evaluated parameters and maintained its quality for a longer time. As a conclusion, considering the positive effects of Aloe vera gel, it can be in order to increase the shelf-life and maintaining the quality of apricot fruits.

    Keywords: Aloe vera, Antioxidant Activity, apricot, Titratable acidity, Total Soluble Solids
  • Fatemeh Jafar Jafari, Afshin Javadi * Pages 221-232

    Pistachio, one of the export products of Iran, under unfavorable conditions during storage mold spoilage and toxins production, especially aflatoxins by Aspergillus parasiticus and Aspergillus flavuse, and moisture absorption decrease the quality of the product. The main objective of this study was evaluating the effect of pistachio coating with chitosan and walnut leaf extract solution in its shelf life. Pistachios were coated by prepared 1.5 and 3% (w/v) chitosan and walnut leaves extract solutions individually and binary and its impact on the moisture content, peroxide value, pests, fungal count and sensory properties of the pistachios were assessed base on national standards of Iran. Data were analyzed by ANOVA test and mean comparisons at a confidence level of 5%. The pests in coated pistachios were significantly different from control ones (p < 0.05). The effect of chitosan edible coating with walnut leaves extract during storage time on the sensory properties was not significant. In each time, moisture content of control sample (3.12%) was significantly lower than coated ones (4.99% for the sample containing 3% chitosan and 3% walnut extract)(p < 0.05). Besides, increasing concentrations of chitosan were increased antioxidant and antimicrobial effects, maintained the sensory properties and were effective in preventing oxidation and fungal activity in pistachios. The lowest peroxide content was observed for samples containing 3% chitosan and 1.5% walnut extract. According to the results, the best solution containing a composition of 1.5% chitosan and 1.5% walnut leaf extract was suggested to increase the shelf life of pistachio. Pistachio, one of the export products of Iran, under unfavorable conditions during storage mold spoilage and toxins production, especially aflatoxins by Aspergillus parasiticus and Aspergillus flavuse, and moisture absorption decrease the quality of the product. The main objective of this study was evaluating the effect of pistachio coating with chitosan and walnut leaf extract solution in its shelf life. Pistachios were coated by prepared 1.5 and 3% (w/v) chitosan and walnut leaves extract solutions individually and binary and its impact on the moisture content, peroxide value, pests, fungal count and sensory properties of the pistachios were assessed base on national standards of Iran. Data were analyzed by ANOVA test and mean comparisons at a confidence level of 5%. The pests in coated pistachios were significantly different from control ones (p < 0.05). The effect of chitosan edible coating with walnut leaves extract during storage time on the sensory properties was not significant. In each time, moisture content of control sample (3.12%) was significantly lower than coated ones (4.99% for the sample containing 3% chitosan and 3% walnut extract)(p < 0.05). Besides, increasing concentrations of chitosan were increased antioxidant and antimicrobial effects, maintained the sensory properties and were effective in preventing oxidation and fungal activity in pistachios. The lowest peroxide content was observed for samples containing 3% chitosan and 1.5% walnut extract. According to the results, the best solution containing a composition of 1.5% chitosan and 1.5% walnut leaf extract was suggested to increase the shelf life of pistachio. Pistachio, one of the export products of Iran, under unfavorable conditions during storage mold spoilage and toxins production, especially aflatoxins by Aspergillus parasiticus and Aspergillus flavuse, and moisture absorption decrease the quality of the product. The main objective of this study was evaluating the effect of pistachio coating with chitosan and walnut leaf extract solution in its shelf life. Pistachios were coated by prepared 1.5 and 3% (w/v) chitosan and walnut leaves extract solutions individually and binary and its impact on the moisture content, peroxide value, pests, fungal count and sensory properties of the pistachios were assessed base on national standards of Iran. Data were analyzed by ANOVA test and mean comparisons at a confidence level of 5%. The pests in coated pistachios were significantly different from control ones (p < 0.05). The effect of chitosan edible coating with walnut leaves extract during storage time on the sensory properties was not significant. In each time, moisture content of control sample (3.12%) was significantly lower than coated ones (4.99% for the sample containing 3% chitosan and 3% walnut extract)(p < 0.05). Besides, increasing concentrations of chitosan were increased antioxidant and antimicrobial effects, maintained the sensory properties and were effective in preventing oxidation and fungal activity in pistachios. The lowest peroxide content was observed for samples containing 3% chitosan and 1.5% walnut extract. According to the results, the best solution containing a composition of 1.5% chitosan and 1.5% walnut leaf extract was suggested to increase the shelf life of pistachio. Pistachio, one of the export products of Iran, under unfavorable conditions during storage mold spoilage and toxins production, especially aflatoxins by Aspergillus parasiticus and Aspergillus flavuse, and moisture absorption decrease the quality of the product. The main objective of this study was evaluating the effect of pistachio coating with chitosan and walnut leaf extract solution in its shelf life. Pistachios were coated by prepared 1.5 and 3% (w/v) chitosan and walnut leaves extract solutions individually and binary and its impact on the moisture content, peroxide value, pests, fungal count and sensory properties of the pistachios were assessed base on national standards of Iran. Data were analyzed by ANOVA test and mean comparisons at a confidence level of 5%. The pests in coated pistachios were significantly different from control ones (p < 0.05). The effect of chitosan edible coating with walnut leaves extract during storage time on the sensory properties was not significant. In each time, moisture content of control sample (3.12%) was significantly lower than coated ones (4.99% for the sample containing 3% chitosan and 3% walnut extract)(p < 0.05). Besides, increasing concentrations of chitosan were increased antioxidant and antimicrobial effects, maintained the sensory properties and were effective in preventing oxidation and fungal activity in pistachios. The lowest peroxide content was observed for samples containing 3% chitosan and 1.5% walnut extract. According to the results, the best solution containing a composition of 1.5% chitosan and 1.5% walnut leaf extract was suggested to increase the shelf life of pistachio.

    Keywords: Coating, Chitosan, Walnut leaf, Pistachio