فهرست مطالب

  • سال شانزدهم شماره 4 (پیاپی 64، مهر و آبان 1399)
  • تاریخ انتشار: 1399/05/02
  • تعداد عناوین: 12
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  • فرناز صادقی، لیلا ناطقی* صفحات 343-356

    افزایش سطح آگاهی مردم و نگرانی در خصوص استفاده از نگهدارنده های شیمیایی، کاربرد مواد نگهدارنده و ضد میکروبی گیاهی و اثر آن بر رشد میکروارگانیسم های مهم غذایی افزایش یافته است. لذا هدف کلی از این پژوهش بررسی خصوصیات فیزیکوشیمیایی، ضدمیکروبی و حسی پنیر سفید آب نمکی حاوی اسانس کندر در غلظت های (5/0، 6/0، 7/0 درصد) و اسانس موسیر در غلظت های (05/0، 1/0، 2/0 درصد) به همراه باکتری لیستریا مونوسیتوژنز به میزان cfu/ml103 به نمونه های شیر پیش ساز پنیر طی 60 روز نگهداری بود. نتایج بررسی ضد میکروبی نشان داد میانگین شمارش میکروبی در تیمار های 2/0 درصد اسانس موسیر و 7/0 درصد اسانس کندر در انتهای دوره نگهداری به ترتیب cfu/ml 000/0 و  cfu/ml7/14 بود، که در مقایسه با سایر تیمار ها بیشترین کاهش را نشان دادند (05/0≤p. نتایج حاصل از بررسی خصوصیات فیزیکوشیمایی انجام شده، نشان داد که این جایگزینی روی خواص فیزیکوشیمیایی پنیر اثر معنی داری نداشت (05/0>p). نتایج ارزیابی حسی پنیر نشان داد اختلاف معنی داری بین امتیاز پذیرش کلی تمامی تیمارهای مورد آزمون و نمونه شاهد مشاهده نگردید، بنابراین می توان از دو اسانس موسیر و کندر به عنوان جایگزین مناسب نگهدارنده های شیمیایی در محصولات لبنی استفاده نمود بدون اینکه اثر نامطلوب روی خواص حسی محصول داشته باشد.

    کلیدواژگان: پنیر سفید آب نمکی، لیستریا مونوسیتوژنز، کندر، موسیر، اسانس
  • رضا فرهمندفر*، سمیه سلمانی، هدا فهیم صفحات 357-365

    برشته کردن یکی از فرآیندهایی است که مقدار ترکیبات مغزهای خوراکی را تغییر می دهد. هدف از این مطالعه بررسی تاثیر شرایط برشته کردن بر میزان محتوی آلفا و گاماتوکوفرول بود. در مطالعه حاضر، اثر دما (120 و 150 درجه سانتی گراد)، و زمان (صفر، 20، 30 و 40 دقیقه) برشته کردن بر میزان آلفاتوکوفرول و گاماتوکوفرول باقی مانده در چهار مغز بادام درختی، فندق، بادام زمینی و پسته مورد بررسی قرار گرفت. برشته کردن یکی از روش های معمول فرآوری مغزهای خام بوده که می تواند بر مقدار توکوفرول مغزها اثر بالایی داشته باشد. نتایج نشان دادند که مقدار آلفاتوکوفرول بادام درختی در دمای 120 درجه سانتی گراد و گاماتوکوفرول در هر دو دمای اعمالی در طول 20 دقیقه ابتدایی برشته کردن افزایش یافته ولی با ادامه فرآیند تا 40 دقیقه مقدار آن کاهش یافت. در فندق، بادام زمینی و پسته نیز مقدار آلفا و گاماتوکوفرول تا دقیقه 20، افزایش یافته ولی در ادامه حرارت دهی کاهش یافت. به طور کلی در دمای 150 درجه سانتی گراد، پس از 20 دقیقه میزان توکوفرول مغزها شروع به کاهش کرد در حالی که در دمای 120 درجه سانتی گراد روند کاهشی پس از 30 دقیقه نمود یافت. افزایش مقدار توکوفرول ها در ابتدای برشته کردن به سبب آسیب دیواره های سلولی بوده و توکوفرول های متصل به ترکیباتی همچون فسفولیپیدها با سهولت بیشتری خارج می شوند. در ادامه برشته کردن، به دلیل حساسیت این ترکیبات به حرارت، تجزیه حرارتی آنها رخ داده و کاهش می یابند.

    کلیدواژگان: بادام درختی، بادام زمینی، برشته کردن، پسته، فندق
  • حدیثه کریمی، حجت الله بداقی*، احمد رجایی، شیده موجرلو صفحات 367-381

    پژوهش حاضر به منظور بررسی فعالیت ضدقارچی و پایداری اسانس آویشن درون پوشانی در نانوژل کیتوزان- مریستیک اسید در برابر قارچ Botrytis cinerea در انگور قرمز شاهرودی انجام گرفت. اثر نانوژل کیتوزان-مریستیک اسید در سه سطح صفر، 150 و 300 میکرولیتر در لیتر ، اسانس آویشن خالص و اسانس آویشن درون پوشانی شده در نانوژل کیتوزان- مریستیک اسید در سه سطح 0، 75 و 150 میکرولیتر در لیتر در شرایط آزمایشگاهی و بر ماندگاری میوه های انگور در شرایط اتمسفر تعدیل یافته در طی 72 روز نگهداری در دمای 2 تا 4 درجه سانتی گراد مورد بررسی قرار گرفت. نتایج طیف سنجی مادون قرمز (FTIR) اتصال موفقیت آمیز بین گروه های آمین کیتوزان و گروه های کربوکسیلیک اسید- مریستیک اسید را تایید کرد و تصویر میکروسکوپ الکترونی روبشی اندازه ذرات نانوژل کیتوزان- مریستیک اسید حاوی اسانس را کمتر از 100 نانومتر نشان داد. تست رهایش نشان داد که انتشار اسانس آویشن از نانوژل کیتوزان- مریستیک اسید روندی دو مرحله ای دارد. نتایج حاصل از حبه های آلوده بسته بندی شده تایید کرد با افزایش غلظت اسانس آویشن، اثر ضدقارچی نیز افزایش یافته است. کمترین میزان هدایت الکتریکی و تغییر رنگ، بالاترین مولفه L* و شاخص کروما در تیمار اسانس آویشن با غلظت 75 میکرولیتر در لیتر مشاهده گردید. نتایج نشان دادند که غلظت های پایین اسانس درون‎پوشانی شده در کنترل عامل قارچ بوتریتیس انگور بهتر از اسانس خالص با همان غلظت عمل کرد، در حالی که در آزمایش های مربوط به قابلیت انبارمانی میوه انگور تیمار اسانس آویشن با غلظت 75 میکرولیتر در لیتر مطلوبترین نتیجه را نشان داد.

    کلیدواژگان: نانوکپسوله، اثر ضدقارچی، اسانس آویشن، Botrytis cinerea، انگور
  • بهروز علیزاده بهبهانی*، فخری شهیدی صفحات 383-394

    در این پژوهش، موسیلاژ از دانه های کامل فرنجمشک با استفاده از آب گرم استخراج شد. پوشش ضدمیکروبی موسیلاژ دانه فرنجمشک همراه با غلظت های صفر، 1، 5/1 و 2 درصد اسانس زنیان تولید شد. آزمون های میکروبی (شمارش کلی، شمارش باکتری های سرمادوست، شمارش کلی قارچ ها (کپک و مخمر)، اشرشیاکلی و استافیلوکوکوس اوریوس)، برخی از آزمون های شیمیایی (عدد پراکسید و pH) و ارزیابی حسی (رنگ، بو و پذیرش کلی) برای نمونه های گوشت گوسفندی نگهداری شده در دمای یخچال (4 درجه سانتی گراد) در روزهای صفر، 3، 6 و 9 انجام پذیرفت. براساس آزمون های میکروبیولوژی زمان ماندگاری نمونه پوشش داده شده با موسیلاژ فرنجمشک (فاقد اسانس) و نمونه های پوشش دهی شده حاوی غلظت های 1، 5/1 و 2 درصد اسانس زنیان نسبت به نمونه کنترل (فاقد پوشش و اسانس) به ترتیب 3، 6، 6 و 6 روز افزایش یافت. نتایج نشان داد که pH نمونه های گوشت گوسفندی پوشش داده شده با موسیلاژ فرنجمشک و نمونه های حاوی اسانس زنیان نسبت به نمونه کنترل در طول دوره نگهداری (9 روز) کمتر بود. نتایج نشان داد که میزان عدد پراکسید در نمونه کنترل از 4/0 تا 7/9 میلی اکی والان پراکسید در طی 9 روز نگهداری در دمای یخچال افزایش یافت. به طور کلی پوشش خوراکی ضدمیکروبی موسیلاژ دانه فرنجمشک حاوی اسانس زنیان به خوبی توانست عمر انبارمانی گوشت گوسفندی را در دمای یخچال افزایش دهد.

    کلیدواژگان: پوشش خوراکی، عدد پراکسید، عمر ماندگاری، موسیلاژ
  • مسعود حفیظ، زهرا شیخ الاسلامی* صفحات 395-408

    امروزه استفاده از صمغ های بومی در فرآورده های غلات با هدف بهبود کیفیت رو به افزایش است. در این تحقیق، اثر دو نوع صمغ فارسی و ریحان در سطوح صفر تا یک درصد با کمک طرح مرکب مرکزی بر پارامترهای فعالیت آبی، رطوبت، حجم مخصوص، تخلخل، سختی و کشش پذیری نان حجیم بررسی گردید. نتایج نشان داد که با افزایش میزان صمغ ها در فرمول نان حجیم، میزان فعالیت آبی کاهش ولی میزان رطوبت، ویژگی های حسی، سختی و کشش پذیری افزایش یافت. در حالی که امتیاز ویژگی‏های حسی (رنگ پوسته، بافت، بو، مزه و پذیرش کلی)، حجم مخصوص و تخلخل نمونه ها با افزایش درصد صمغ ها ابتدا افزایش و سپس کاهش یافت. قابل ذکر است که نمونه حاوی 46/0 درصد صمغ دانه ریحان و 35/0 درصد صمغ دانه فارسی کمترین میزان سختی و بیشترین میزان حجم مخصوص، تخلخل و کشش پذیری را از خود نشان داد و این نمونه به عنوان نمونه بهینه معرفی شد. با بررسی ریز ساختار نمونه بهینه با نمونه فاقد صمغ نیز مشخص گردید، نمونه حاوی صمغ ریحان و فارسی از بافت یکنواخت‏تری در مقایسه با نمونه شاهد برخوردار بود.

    کلیدواژگان: بهینه یابی، نان حجیم، صمغ دانه ریحان، صمغ فارسی، میکروسکوپ الکترونی
  • مرضیه مومنی سروستانی، حنان لشکری* صفحات 409-421

    اسانس زیره سیاه فعالیت آنتی اکسیدانی و ضدمیکروبی بالایی دارد و می تواند منجر به بهبود و ارتقای ماندگاری سیستم های غذایی گردد. به منظور بررسی تاثیر اسانس زیره سیاه بر خصوصیات فیزیکوشیمیایی، میکروبی و حسی پنیر فتای فراپالایش غلظت های مختلف اسانس زیره سیاه (صفر، 05/0، 1/0 و 15/0 درصد) به پنیر اضافه شد و نمونه های پنیر در روزهای 3، 20 و 60 دوره نگهداری آنالیز شدند. نتایج نشان داد که اسانس زیره سیاه دارای تاثیر معنی داری در سطح احتمال 5% بر اسیدیته، pH و خاصیت آنتی اکسیدانی بوده و  با افزایش اسانس pH کاهش و اسیدیته و خاصیت آنتی اکسیدانی افزایش یافتند. همچنین اسانس زیره سیاه در سطح احتمال 5% اثر معنی داری بر روی میزان پروتیین، چربی، نمک و ماده خشک پنیر نداشت. نتایج نشان داد دوره نگهداری بر میزان چربی، نمک و پروتیین تاثیر معنی داری نداشت. با افزایش درصد اسانس در پنیر، به طور معنی داری (P<0.05) شاخص L*کاهش و شاخص b* افزایش یافت. بررسی خصوصیات حسی در طی دوره نگهداری نشان داد، افزودن اسانس بر روی رنگ، بافت تاثیر معنی داری نداشته ولی بر طعم و پذیرش کلی تاثیر معنی دار است. طعم پنیر در پایان دوره نگهداری نسبت به روز سوم و بیستم کاهش معنی داری نشان داد. در مجموع تیمار حاوی 05/0 درصد اسانس از نظر خصوصیات حسی دارای بالاترین امتیاز بود.

    کلیدواژگان: اسانس، پنیر، زیره سیاه، فیزیکوشیمیایی، میکروبی
  • میترا منصوری بنی، وحید سماواتی، مرضیه بلندی* صفحات 423-435

    در این مطالعه بهینه یابی تاثیر پارامترهای عملیاتی برکاهش کلسترول خامه توسط بتاسیکلودکسترین مورد بررسی قرار گرفت و با آنالیز پارامترهای موثرعملیاتی شامل غلظت بتاسیکلودکسترین (5/1،0، 5/1%) و دمای اختلاط (10، 30، 50 درجه سانتی گراد) و زمان اختلاط (5، 15، 25 دقیقه) شرایط عملیاتی بهینه برای دستیابی به فرآیندی با راندمان بالا بررسی گردید و از طراحی آزمایشات به کمک روش سطح پاسخ و طرح باکس بنکن استفاده شد. حداکثر کاهش کلسترول (%92/89) در غلظت 42/1% بتاسیکلودکسترین، دمای اختلاط 76/45 درجه سانتی گراد و زمان 87/23 دقیقه مشاهده گردید. نتایج به دست آمده از بررسی اثر مستقل متغیرها نشان داد که عامل غلظت شدت تاثیر کمتری بر کاهش کلسترول خامه دارد اما دما و زمان تاثیر مثبت موثرتری بر کاهش کلسترول دارند. در بین اثرات متقابل فاکتورهای مورد بررسی بیشترین اثر مربوط به تاثیر همزمان دما و زمان (%9/88) و کمترین اثرمربوط به تاثیر همزمان غلظت و دما (%5/85) مشاهده شد.

    کلیدواژگان: خامه، بهینه یابی، کلسترل، سیکل دکسترین، سطح پاسخ
  • فاطمه ایوانی، بهزاد ناصحی*، محمد نوشاد، حسن برزگر صفحات 437-452

    امروزه تمایل مصرف کننده به محصولات سلامتی بخش افزایش یافته است. از آنجایی که کیک های رایج با کمبود ترکیبات ارزشمندی مانند فیبر و آنتی اکسیدان همراه هستند، پژوهشگران به دنبال غنی سازی آنها با مواد مختلف دورریز می باشند. در این پژوهش اثر جایگزینی آرد گندم با پودر هسته انار (صفر تا 50 درصد) و صمغ زانتان (صفر تا 3/0درصد) بر خصوصیات فیزیکوشیمایی (تخلخل، شاخص حجم، فیبر، پروتیین)، کیفی (دانسیته، سفتی، افت وزنی، تقارن، حجم، رنگ) و حسی (بافت، سفتی، عطر و طعم، قابلیت جویدن، پذیرش کلی) کیک با استفاده از روش سطح پاسخ مورد ارزیابی قرار گرفت. یافته ها نشان داد که افزایش جایگزینی پودر هسته انار تاثیر مثبت و معنی داری بر محتوای فیبر، پروتیین و افت وزنی و تاثیر منفی بر روی ویژگی های دانسیته، سفتی بافت، تقارن، شاخص حجم، شاخص های رنگی، پذیرش کلی و عطر و طعم نمونه ها داشت. همچنین افزایش درصد صمغ زانتان تاثیر مثبت و معنی داری بر روی ویژگی های دانسیته، سفتی بافت، حجم، تخلخل، شاخص حجم و افت وزنی نمونه ها داشت. به طور کلی ارزیابی تمام ویژگی ها نشان داد که نمونه کیک حاوی 1/0 درصد صمغ و 22/22 درصد پودر هسته انار دارای بهترین کیفیت است. از سوی دیگر مقایسه نمونه بهینه و شاهد حاکی از ان است که جایگزینی پودر هسته انار سبب افزایش ترکیبات فنولی و کاهش عدد پراکسید شده است.

    کلیدواژگان: هسته انار، فراسودمند، فیبر رژیمی، کیک اسفنجی
  • شراره رضائیان، حمیدرضا پوریانفر، شادی بلوریان، حامد صابریان* صفحات 453-464

    قارچ خوراکی- دارویی انوکی (Enoki) Flammulina velutipes  پنجمین قارچ از نظر جایگاه تولید جهانی است که علاوه بر ارزش تغذیه ای، دارای خواص اثبات شده درمانی و دارویی متعددی می باشد. این پژوهش با هدف بررسی امکان تولید نوشیدنی فراسودمند بر پایه قارچ انوکی همراه با رنگ طبیعی کورکومین شکل گرفت. ابتدا میسلیوم خالص نژاد تجاری قارچ انوکی تهیه و سپس تولید اندام میوه دهی تازه بر روی بستری متشکل از 40% کاه گندم+ 40% خاک اره + 18% سبوس گندم +1% گچ + 1% آهک انجام گردید. اندام میوه دهی قارچ به دو شکل مختلف پوره و پالپ به عنوان ماده زمینه ای اصلی نوشیدنی در قالب آزمون های حسی و ریولوژیکی مورد استفاده قرار گرفت. متغیرهای مستقل آزمون فاکتوریل شامل غلظت پوره قارچ و غلظت صمغ بود. نوع طعم دهنده و غلظت رنگ کورکومین نیز در آزمایشات جداگانه ای مورد ارزیابی قرار گرفتند. آزمون ریولوژیکی نشان داد که رفتار جریانی نوشیدنی، شبه پلاستیک بود و بدون اعمال تنش حالتی ژله ای داشت و ذرات کاملا در آن شناور بودند. آزمون های حسی حاکی از آن بودند که بیشترین و کمترین امتیاز طعم به ترتیب مربوط به نمونه های حاوی 5% و 10% قارچ بود (p<0.05). در همه شاخص ها و به خصوص پذیرش کلی، نوشیدنی پالپ دار به طور معنی داری بهتراز نوشیدنی پوره دار بود (p<0.05). همچنین افزودن رنگ طبیعی کورکومین به نوشیدنی پالپ دار در حد 05/0% موجب افزایش پذیرش حسی آن شد. یافته های این تحقیق نشان داد که نوشیدنی بر پایه قارچ انوکی به شکل پالپ دار می تواند از پتانسیل پذیرش بالایی توسط مصرف کنندگان برخوردار باشد زیرا به دلیل استفاده از قارچ خوراکی- دارویی و رنگ طبیعی کورکومین دارای خواص فراسودمند بوده و فاقد عوارض جانبی می باشد.

    کلیدواژگان: قارچ انوکی، کورکومین، نوشیدنی فراسودمند، ویژگی های فیزیک و شیمیایی
  • زهره بوربورمرادی، لیلا ناطقی*، اورنگ عیوض زاده صفحات 465-478

    مصرف زیاد نمک در رشته آشی منجر به ابتلا و پیشرفت بیماری پرفشاری خون می گردد و از طرفی کاهش نمک منجر به ایجاد مشکلاتی نظیر سست شدن و ریزش رشته آشی در هنگام خشک کردن و یا منجر به وا رفتن رشته در هنگام جوش، می گردد. استفاده از صمغ ها در فرمولاسیون رشته آشی می تواند اثرات مخرب کاهش نمک بر کیفیت رشته آشی را کاهش دهد. هدف کلی از این پژوهش بررسی اثرات افزودن صمغ زدو در غلظت های 2/0، 4/0، 6/0، 8/0، 1و 2/1% بر مبنای وزن آرد به جای نمک مورد استفاده در فرمولاسیون رشته آشی شاهد (5/4%) بر ویژگی های ریولوژیکی خمیر رشته آش و همچنین ارزیابی خواص فیزیکوشیمیایی، بافتی، رنگ سنجی، کیفی و حسی رشته آشی کم نمک یک روز پس از تولید بود. بنابراین 7 تیمار به همراه شاهد مطابق با طرح کاملا تصادفی طراحی گردید. نتایج آزمون های ریولوژیکی خمیر نشان داد که کاهش نمک و افزایش صمغ زدو اثر معنی داری (05/0≥p) بر خواص ریولوژی خمیر رشته آش شامل متوسط حداکثر ارتفاع منحنی، متوسط طول منحنی، شاخص تورم، متوسط سطح زیر منحنی، تست پیکربندی و الاستیسیته داشته است. ارزیابی نتایج فیزیکوشیمیایی نشان داد با اضافه نمودن صمغ زدو و کاهش میزان نمک میزان رطوبت افزایش و میزان خاکستر و نمک به صورت معنی داری کاهش یافت. نتایج آزمون بافت سنجی توسط دستگاه آنالیز پروفایل بافت نشان داد با کاهش نمک و افزایش غلظت صمغ زدو و میزان سختی تیمارها روند کاهشی نشان داد. نتایج آزمون رنگ سنجی نشان داد که اختلاف آماری معنی داری در مولفه های رنگی a ، b و L بین کلیه تیمارها با نمونه شاهد مشاهده نگردید. بررسی ویژگی های کیفی رشته های آشی نشان داد با کاهش میزان نمک به 90/3% و افزودن صمغ زدو تا غلظت 6/0% وزن رشته های ناهمگون، وزن رشته های نیمه شکسته و شکسته در مقایسه با شاهد روند کاهشی نشان داد و در غلظت های بالاتر از 6/0% صمغ زدو این تغییرات روند افزایشی نشان داد. نتایج ارزیابی حسی نشان داد با کاهش میزان نمک تا 90/3% و افزودن 6/0% صمغ زدو امتیاز بو، رنگ، بافت و پذیرش کلی تیمارها اختلاف معنی داری در مقایسه با نمونه شاهد نشان نداد. امتیاز مزه تمامی تیمارها اختلاف معنی داری با نمونه شاهد نداشت. نتایج این تحقیق نشان داد میتوان میزان نمک رشته آش را تا 6/0 کاهش داد و به جای آن صمغ زدو اضافه نمود بدون اینکه اثر نامطلوبی بر خواص کیفی، بافتی و حسی رشته آش در مقایسه با شاهد داشته باشد بنابراین تیمار مذکور به عنوان تیمار برتر انتخاب گردید.

    کلیدواژگان: رشته آشی، صمغ زدو، آلوئولب، آنالیز پروفیل بافت، کم نمک
  • فائزه جمالیزاده، مهدی قاسمی ورنامخواستی*، مهدی قاسمی نافچی، مجتبی توحیدی، مجید دولتی صفحات 479-491

    ادویه جات از با ارزش ترین گیاهان دارویی مورداستفاده در صنایع غذایی و علم پزشکی هستند و با توجه به تفاوت کیفیت و قیمت بین گونه های مختلف، تشخیص، طبقه بندی و جداسازی آن ها براساس خلوص و درجه کیفیت از اهمیت بالایی برخوردار است. ادویه ها درکشورهای مختلفی از جمله هندوستان، پاکستان، چین و کشورهای آسیای شرقی و جنوبی تولید می شوند. در این پژوهش، یک سامانه ماشین بویایی بر پایه هشت حسگر نیمه هادی اکسید فلزی در ترکیب با روش های تشخیص الگو به منظور طبقه بندی و جداسازی ادویه فلفل سیاه براساس منشاء جغرافیایی و تشخیص تقلب های کبابه چینی و پودر هسته خرما به کارگرفته شد. به منظور تحلیل داده های استخراج شده از سیگنال پاسخ حسگرها از روش تحلیل مولفه های اصلی (PCA) استفاده شد. براساس نتایج حاصل، آنالیز مولفه های اصلی با مجموع دو مولفه اصلی اول %96 برای نمونه های فلفل سیاه براساس منشاء جغرافیایی و 95% برای تقلب های کبابه چینی و هسته خرما از واریانس داده ها قابل توصیف است. همچنین از سه روش تحلیل تفکیک خطی (LDA)، ماشین بردار پشتیبان (SVM) و درخت تصمیم گیری (DT) برای طبقه بندی نمونه ها استفاده شد. استفاده از روش LDA، برای نمونه های فلفل سیاه دقت طبقه بندی 100% و برای تقلب ها دقت 14/97% را نشان داد. نتایج نشان داد که SVM با تابع گاوسی بالاترین دقت را در طبقه بندی نمونه های فلفل سیاه، تقلب کبابه چینی و تقلب هسته خرما را دارد. همچنین میزان موفقیت روش DT در تفکیک و طبقه بندی نمونه های فلفل سیاه، تقلب کبابه چینی و تقلب هسته خرما به ترتیب 66/96% و 5/88% برآورد شد.

    کلیدواژگان: ماشین بویایی، فلفل سیاه، کبابه چینی، هسته خرما
  • سهیل ریحانی پول، سید علی جعفرپور* صفحات 493-505

    به دنبال انجام تحقیقات گسترده در زمینه خواص ضدباکتریایی و آنتی اکسیدانی پروتیین های آبکافتی و کیتوزان و رضایت بخش بودن نتایج، استفاده کاربردی از این ترکیبات به عنوان نگهدارنده های طبیعی در مواد غذایی مختلف ضروری به نظر می رسد. هدف از مطالعه حاضر نیز بررسی خواص این ترکیبات در نگهداری فیله ماهی قزل آلای رنگین کمان (Oncorhynchus mykiss) در دمای یخچال است. به همین منظور، فیله های ماهی با محلول کیتوزان (تیمار 2) و کیتوزان حاوی پروتیین آبکافتی (تیمار 3) پوشش داده شدند و به همراه شاهد (تیمار 1) در روزهای صفر، 4، 8، 12، 16 و 20 نگهداری در یخچال مورد آزمون های شیمیایی و میکروبی قرار گرفتند. نتایج آزمون های شیمیایی نشان داد که مقادیر شاخص های TBA، TVN-B و FFA ضمن داشتن روند افزایشی در طول دوره، در اکثر روزهای مورد بررسی (به خصوص روزهای پایانی) به صورت معنی داری در تیمار 3 کمتر از تیمارهای 1 و 2 بود (05/0<p). شاخص PV هم در روزهای 12، 16 و 20 در تیمار 3 به صورت معنی داری از تیمار 1 و 2 کمتر بود اما روند افزایشی مستمر با افزایش زمان نگهداری در این شاخص ثبت نشد؛ بلکه در پایان دوره (روز 20) این شاخص در هر سه تیمار نسبت به روز 16 کاهش یافت. یافته های تغییرات pH حاکی از ثبات این شاخص در تیمار 3 در طول دوره نگهداری بود. ضمن اینکه در روزهای 12، 16 و 20، pH تیمار 3 به صورت معناداری کمتر از تیمار 1 و 2 بود (05/0<p). شمارش بار باکتریایی مزوفیل هوازی و سرمادوست در تیمارها (ضمن داشتن روند افزایشی در طول دوره) نشان داد که در روزهای 8، 12، 16 و 20 بار باکتریایی تیمار 3 به طور معناداری کمتر از تیمار 1 و 2 است (05/0<p). بنابراین می توان بیان نمود که پوشش فعال کیتوزان به همراه پپتیدهای زیست فعال قابلیت حفظ کیفیت فیله ماهی قزل آلای رنگین کمان در طول دوره نگهداری در دمای یخچال را دارد.

    کلیدواژگان: پروتئین آبکافتی، کیتوزان، خواص آنتی باکتریالی، خواص آنتی اکسیدانی
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  • Farnaz Sadeghi, Leila Nateghi* Pages 343-356
    Introduction

    There have been great efforts to find safe and potent natural antioxidants from various plant sources. Due to the side effects of chemical preservatives and as a support of the idea for consumption of green natural food, demand for studies on the antimicrobial properties of natural preservatives and essential oils on the important food borne pathogens in vitro and in food products has been increased. Medicinal plants are complex natural mixtures which contain compounds at quite different concentrations, and their antioxidant activities are due to many substances including some vitamins, flavonoids, terpenoids, carotenoids, phytoestrogens, minerals, etc. Essential oils existed in some herbs or their antioxidant components as preservative agents in food makes them to be proposed as potential substitutes of synthetic antioxidants in food stuff.  Antioxidants are also widely used as additives in fats and oils and in food processing to prevent or delay spoilage of foods regarding to the harmful effects of synthetic preservatives on consumers’ health, there is an increasing attention, both in food industry and authorities, to medicinal and aromatic plants as natural preservatives in food products. White brined cheese is a kind of hard cheese which is produced from raw milk of cow, lamb and the main characteristics of the taste are pickling and salinity. White cheese, salt water, including products that may be at the time of manufacture or during storage by microorganisms such as Listeria. The objective of the present study was to investigate physicochemical properties, anti-microbial and sensory properties of frankincense essential oil and shallot oil in white brined cheese.

    Material and methods

    The whole treatments in this research were included: T0 (control), T1 (0.5% (w/w%) Frankincense and 0% shallots essential oil), T2 (0.6% (w/w%) Frankincense and 0% shallots essential oil), T3 (0.7% (w/w%) Frankincense and 0% shallots essential oil), T4 (0% Frankincense and 0.05% (w/w%) shallots essential oil), T5 (0% Frankincense and 0.1% (w/w%) shallots essential oil), T6 (0% Frankincense and 0.2% (w/w%) shallots essential oil), T7 (0.6% Frankincense and 0.1% (w/w%) shallots essential oil). In order to produce a white brine cheese, in the first step, the raw milk was pasteurized at 72 ºC for 15 seconds and cooled at 35ºC, then 5 liters of milk were poured into each of the sterile specialty dishes. Then, Listeria monocytogenes (103 cfu / ml) were then inoculated into milk samples. In the next step frankincense essential oil concentrations (0.5%, 0.1%, 0.6%) and shallot oil concentrations (0.05%, 0.1%, 0.2%) and mixture (0.1%+ 0.6%) were added. Then 0.02% (w/v) calcium chloride was added and after 0.5 % (w/w) of starter culture containing lycoplastic bacteria Lactobacillus bulgaricus and Streptococcus thermophiles were added into the milk samples and mixed. Finally, after the milk pH reached about 6.5, 0.001% (w/v) of microbial rennet was also added (Sanjiu Mito Japan Co.) After dissolving it, sterile water was added into the milk at 35 °C and 8 minutes for milk coagulation resting time was given. After coagulation (60 min), the cheese samples were cut into 1-2 cm slices and wrapped in a cloth to be kept in room temperature for 6 hours under 12 kg weight plates for dewatering. Coagulants were impregnated in 20% (w/v) salt water for 6-8 hours after cheese samples were cut while transferring to 8% salt water at 12-14 ° C for 15 days. Therefore, samples after the initial arrival time to arrive at the final arrival were kept at 4 ° C for 60 days (ISIRI NO. 5772, 2001). The essential oils chemical composition were determined by gas chromatography equipped with mass spectroscopy (GC/MS). GC-MS analysis of the essential oil was performed using Agilent-Technologies 6890N. Physicochemical, microbial and sensory properties of samples immediately on days 1, 30, 60 were measured but protein and fat on day 1after produced were measured.  Total protein was determined by macro kjeldahl method with national standard No. 1811 (Anonymous, 1383). Fat was determined by Gerber's method with national standard No. 8587. pH was determined by a MA-Mettler pH-meter and titratable acidity (percentage of lactic acid) was determined by 0.1 normal and phenolphthalein as identifiers using national standard No. 2852 (Anonymous, 1385). Level of moisture was determined by national standard No. 1753 (Anonymous, 1381). Salt percentage was determined by Moher method with national standard No. 1809 (Anonymous, 1356). To measure the number of Listeria monocytogenes, the microorganisms were measured in Palcam Agar Surface cultivation method at 30ºC for 72 hours (Khosravi and Malekan, 2004). Sensory analysis was performed by 10 trained panelists using a five point hedonic method with scales of one (very good), two (good), three (average), four (bad), and five (very bad) for taste, smell, texture, and overall acceptability with national standard No. 3442 (Anonymous, 1387). In order to design the treatments, a completely randomized design with factorial arrangement was used. For data comparison, Duncan's test was used at 95% confidence level. Minitab 16 software was used to analyze the statistical data.

    Results and discussion

    The results showed that the antimicrobial essential oils of the highest possible antimicrobial against Listeria monocytogenes was shallots average number of bacterial treatments 0.2% essential oil shallots (T5) and 0.7% Frankincense essential oil (T3) at the end of the maintenance period cheese was 0.147 ×102 cfu/ml and 0.000 cfu/ml, respectively, when compared with other treatments maximum reduction showed (p≤0.05). Sensory evaluation results showed that the control cheeses had the highest sensory acceptability. Given that treatment with 0.2 shallot oil had the highest germicidal effect and organoleptic properties statistically significant difference between treatment and control samples were not mentioned. Therefore, the use of essential oils 0.2% in the formulation of white cheese shallot salt water in order to prevent the growth of Listeria monocytogenes is recommended and the treatment was selected as the best treatment.

    Keywords: White brine cheese, Listeria monocytogenes, Frankincense, shallots, essential oil
  • Reza Farahmandfar*, Somayeh Salmani, Hoda Fahim Pages 357-365
    Introductıon

    Nuts are one of the major resources of bioactive compounds such as tocopherols, tocotrienols, sterols (Jensen and Lauridsen, 2007). Tocopherols include 8 natural homologues that all of them belongs to vitamin E group (Chun, 2002). It is well known that vitamin E has good antioxidant activity and among its isomers, α-tocopherol and γ-tocopherol have highest biological activity and free radical scavenging, respectively (Grilo et al., 2014). In recent years, the beneficial health effects of vitamin E on some disease such as cancer and heart disorders attract researcher’s attentions (Wagner et al., 2004).Roasting process changes the chemical and nutritional properties of nuts, including antioxidants, vitamins, colors, and aroma mostly through Maillard reaction (Alamprese et al., 2009; Ballistreri et al., 2009). Due to the importance of vitamin E antioxidant activity and its heat sensitivity, the residual amounts of them after different roasting conditions were investigated. 

    Materials and methods

    Samples were spreaded in alominum foil and placed in forced air oven at 120 and 150 ºC and different time intervals including 0, 20, 30 and 40 min. After roasting, samples were powdered, then 0.5 g of each sample plus 0.05 g ascorbic acid were added to 0.5 mL ethanol (90.2%) and 0.5 mL KOH and mixed in a tube (16× 125 mm). The tube was then placed in water bath for 30 min. Then, the tube were placed in ice bath for 5 min, then 3 mL deionized water, 5 mL hexane were added to the tube and vortexed for 30 s and centrifuged for 10 min at 1000 rad/s at ambient temperature. The extraction was done twice. Hexane layer evaporated with nitrogen then 1 mL of mobile phase added to tube and vortexed again. Prepared samples then were injected to HPLC (Knuer- Germany).

    Results and discusion

     Based on the obtained results, α-tocopherol content in almond was more than γ-tocopherol. After 20 and 30 min of roasting, at 150 and 120 ºC respectively, the amount of α-tocopherol slightly increased, while it decreased with increasing roasting time. γ-tocopherol content in almond at both temperatures also increased up to 20 min roasting and decreased till the end of process. In hazelnut, at both temperatures up to 20 min and then decreased till end of roasting process. This trend was shown for peanut tocopherols as well. With increasing in roasting time, α-tocopherol and γ-tocopherol content decreased to their initial level. It has suggested that tocopherols which attached to the other components such as phospholipids released more conveniently under thermal treatment like roasting which leads to increase their concentrations at initial of thermal process. In pistachio, 150 and 120 ºC respectively caused to increase in γ-tocopherol content, respectively while its content decreased up to the end of roasting time (40 min). α-tocopherol content at both temperatures increased after 20 min, then decreased gradually as time passes. Results indicated that both time and temperature of roasting had a significant effect on α- and γ-tocopherol of four nuts. Although both of temperatures in our study significantly on increased vitamin E isomers at the start of roasting process, their contents decreased with increasing in roasting time. Maximum amount of both isomers were detected at 120 ºC after 30 min and at 150 ºC after 20 min.

    Keywords: almond, peanut, roasting, pistachio, hazelnut
  • Hadise Karimi, Hojatollah Bodaghi*, Ahmad Rajaei, Shideh Mojerlou Pages 367-381
    Introduction

    Fresh grapes (Vitis vinifera L.) show severe lesions at the post-harvest stage and during the storage period. Decreasing the quality of grapes in the post-harvest stage limits its consumption and commercialization. Some methods such as using bio-control agents, natural antimicrobials, physical methods, disinfectants agents ,GRAS, (ozone, ethanol, acetic acid) have been used to control Botrytis cinerea after harvest. Encapsulation of the essential oils will increase their ability by increasing the effectiveness of the essential oils. Currently, chitosan has been interested for encapsulating bioactive compounds, as they are generally known to be safe and possess superior biological properties such as biodegradability, biocompatibility and non-toxicity. The aim of this study was to encapsulate thyme essential oil in chitosan nanogels to enhance and maintain its antifungal effect against B. cinerea in vitro and in vitro on Shahroodi red grape.

    Materials and methods

    For the purpose of this study, chitosan nanogels were first prepared and the infrared spectrum of chitosan-meric acid nanogels was measured using FT-IR430 infrared spectrophotometer at 20 ° C. The morphology of chitosan-meric acid nanogels and encapsulated essential oil was analyzed by SEM. Release test was then performed to determine the release rate of thyme essential oil encapsulated in chitosan-meric acid nanogels. Effect of chitosan-meristic acid nanogels at three levels of 0, 150 and 300 µl/L, pure thyme essential oil and thyme essential oil encapsulated in chitosan-meristic acid nanogels at three levels of 0, 75 and 150 µl / L in vitro and on the shelf life of grape fruits was studied under modified atmospheric conditions during 72 days storage at 2 to 4 °C. During storage, some traits such as firmness by manual penetrometer, electrical conductivity of fruit tissue, some components of fruit skin color and soluble solids were assessed by a refrectometer.

    Results and discusion

     Infrared spectroscopy (FTIR) results confirmed the successful coupling between chitosan amin groups and carboxylic acid-meristic acid groups and scanning electron microscopy image showed that the particle size of chitosan-meric acid nanogel was than 100 nm. The Comparison of the particle size in the present study with the previous studies on the size of chitosan-meric acid nanogels was smaller and more uniform. These differences could be related to several reasons, transform the long chitosan chain into smaller fragments by initial sonication, the important role of ultrasound in the reduction of the particle size and passing the nanogels through the filter. Release test showed that the diffusion of thyme essential oil from chitosan-meric acid nanogels has a two-step process. The chitosan-meric acid nanogels prepared in this study have hydrophilic (chitosan polymer) and hydrophilic (meristic acid fatty acid chain) regions, which led to the gradual release of thyme essential oil due to their hydrophobic nature. The results of the infected packaged berries confirmed that with increasing concentration of thyme essential oil, the antifungal effect was also increased. Evaluation of the effects of essential oil and nanogels - essential oils on grape berries infected with pathogenic spores showed the highest number of spores in control treatment (10.125 × 105 per ml) and the lowest number in NE2 (1.375 × 105 per ml) were observed. Coating treatments of chitosan-meric acid nanogel and thyme essential oil encapsulated in chitosan-meric acid nanogels showed better results at higher concentrations, but in the case of essential oil, lower spores were observed. The lowest electrical conductivity and discoloration, the highest L * component and chroma index were observed in thyme essential oil treatment with concentration of 75 µl/l. The results showed that the lower concentrations of the essential oil in the control of botrytis cinerea was better than the pure essential oils, whereas in the experiments on the storage of grape fruit, the treatment of thyme essential oil with a concentration of 75 µl/l It showed the most favorable result. Based on the results of the present study, the effect of essential oil nano-gel and essential oil alone on the shelf life after harvesting of grapes packed with polyethylene film confirmed that the essential oil performance was better than the essential oil nanogel. The lower performance of the essential oil nanogel than that of the essential oil alone can be due to inhibition of the essential oil diffusion through the packaging film while, the encapsulated essential oil release slower than the essential oil alone, it is likely to have an effect longer than expected in this study for the storage period of the grape. Considering this case and the antimicrobial capability of essential oil nanogel, it is necessary to investigate the effect of essential oil nanogel compared to essential oil on longevity of grapes for a longer of storage period.

    Keywords: Nanoencapsulation, unti-fungal, Thyme essential oil, Botrytis cinerea, grape
  • Fakhri Shahidi Pages 383-394
    Introduction

    Meat and meat products undergo chemical and microbial spoilage during production, transportation, storage and consumption. Antimicrobial edible coatings containing natural herbal extracts and essential oil possess various benefits and are currently used to design novel active biodegradable packaging. Natural polysaccharides are considered as potentially good candidates to fabricate edible coatings and provide a shelf life extender. There are no researches in the literature concerning the potential effect of Carum copticum essential oil (CCEO) enriched Scutellaria lateriflora seed mucilage (SLSM) based edible coatings on the quality and shelf life of lamb during refrigeration storage. The objective of this study was therefore to investigate the inhibitory effect of CCEO loaded SLSM edible coating towards lipid oxidation and microbial spoilage of lamb during cold storage conditions.

    Materials and methods

    In this study, SLSM was extracted from whole seeds using hot-water extraction. Edible coating was prepared by dissolving 2 g of the extracted SLSM and 0.1 g of Tween 80 in 100 mL of sterilized distilled water. The mixture was stirred and heated for 2 h. Afterwards, CCEO was added to the SLSM solution at 0, 1, 1.5, and 2%, and the obtained solution was used as an antimicrobial coating for extending the shelf-life of lamb slices. The control and the coated lamb samples were analyzed periodically for microbiological (total viable count, psychrotrophic count, Escherichia coli, Staphylococcus aureus and fungi), chemical (peroxide value and pH), and sensory characteristics (color, odor and overall acceptability).

    Results and discussion

    SLSM extended the microbial shelf life of lamb by 3 days, whereas SLSM + 1% CCEO, SLSM + 1.5% CCEO and SLSM + 2% CCEO resulted in a significant shelf life extension of the lamb by 6, 6, and 6 days, respectively as compared to the control samples. The results demonstrate that the EO-rich edible coating functions as an oxygen barrier and, in turn, limits the growth of most important and aerobic psychrotrophic bacteria, i.e. Pseudomonas species, which are mainly responsible for the fresh lamb spoilage under aerobic conditions. The results showed that the pH of lamb coated with SLSM and samples containing CCEO was lower than the control. The results showed that the peroxide value in the control sample increased from 0.4 to 9.7 meq oxygen/kg during 9 days of refrigerated storage. Based on the finding of this study, the use of CCEO-loaded coating manifestly lowered the meat lipid oxidation. The resultant edible coating manifestly improved the shelf life of lamb through suppressing microbial spoilage and inhibiting lipid oxidation. The coating containing 2% CCEO conferred good quality characteristics to the lamb and expanded its refrigeration shelf life.

    Keywords: Edible coating, Peroxide value, Shelf life, Mucilage
  • Masoud Hafiz, Zahra Sheikholeslami* Pages 395-408
    Introductıon

     In baked foods, hydrocolloids have been used for retarding staling and improving the quality of fresh products ((Ba´rcenas et al 2003, 2004). Researchers found that all hydrocolloids are able to hold moisture loss during crumbing of bread and reduce the rate of water loss and moisture to increase the bread crumb (Arendt, 2013).  Ocimum basilicum L., and Amygdalus scoparia., commonly known as Basil and Farsi gums, are a good source for pharmaceutical, food and industrial applications. The aim of this study was to evaluate the effect of Ocimum Bacilicum and Farsi gums on optimization of loaf bread production by decreasing the hardness and increasing the special volume, porosity and extensibility values by using the response surface method.

    Materials and methods

    The Ocimum bacilicum seeds were first cleaned, then seeds were soaked in distilled water to obtain a water to seed ratio of 37:1 at 40 ˚C and pH = 7. Separation of the hydrocolloid from the swollen seeds was achieved by passing the seeds through an extractor equipped with a rotating plate that scraped the gum layer on the seed surface. The extracted solution was then filtered and dried in an air forced oven at 60˚C and finally the powder was milled, sieved using a mesh 18 sifter, packed and kept at cool and dry condition (Karazhiyan et al., 2010, Mohamad Amini et al., 2007). Farsi gum in powder were bought from Rihan gum Parsian co. The effect of Basil and Farsi seed gum concentration (0-1%) on water activity, moisture, specific volume, hardness and extensibility of bread was investigated. For Data Analysis used SPSS software and Duncan test, for mean comparisons.

    Results and discusions

    The results revealed that the water activity in bread was decreased while an enhancement was observed in moisture, hardness and extensibility with an increase at gum concentration. Further, the specific volume and porosity of bread were increased and then decreased by adding the gum with higher level. In order to reach to a minimum hardness and maximum specific volume, porosity and extensibility, the concentration of Basil and Farsi seed gum should be 0.46 and 0.35% respectively. The results of this study showed that any increase in concentration of gum in the formulation, makes moisture content, hardness and elongation to be increased, but the activity of water decreased. However, with the increase of Farsi gum, the amount of specific volume and porosity increased and then decreased. In the end, it can be stated that, in order to obtain optimal conditions for bread formulation, the percentage of basil and Farsi gum seeds should be 0.42 and 0.35% respectively.

    Keywords: Optimization, Loaf bread, Basil seed gum, Farsi seed gum, Electronic microscope
  • Marziyeh Momeni Sarvestani, Hannan Lashkari* Pages 409-421
    Introduction

    Black cumin is one of the most important and valuable herbal plants that are wildly found in regions of Iran with dry weather such as Kerman, Fars, Isfahan and Yazd. Black cumin seed in traditional medicine is used as anti- flatulence, anti-diarrhea, antipyretic, blood fat and cholesterol reducer, anti-allergic and digestive enhancers. Essential oils are oily liquids that are obtained from different parts of the plant. Different compounds in the essential oil of black cumin include cumin-aldehyde, gamma trypinene, paracymon and other active ingredients, which are often terpene compounds and have numerous uses as anti-bacterial and antioxidant agents. In recent years, consumers have become more concerned with the health issues and are looking to eat foods with higher functional characteristics, as well as higher nutritional value. Therefore, it can be suggested that essential oil of Cumin as a natural and vegetable preservative was used in food. Because cheese is a nutritious environment for the growth of microbes, it always has microbial degeneration.

    Materials and Methods

    Identification of essential oil compound was performed by GC/MS chromatography. In order to evaluate the effect of Black Cumin essential oil on physicochemical, microbial and sensory properties of cheese, different percentages of Black Cumin essential oil (0, 0.05, 0.1% and 0.15%) were added to cheese. Iranian white cheese production was done by ultrafiltration method in Arjan Fars Company. Cheese sample were analyzed at days 3, 30 and 60 of storage time. Acidity, pH, fat, protein and dry matter were measured according to National Standard No. 2852, 2852, 8785, 1811, 1753 respectively. To measure the inhibition of free radicals of DPPH, method of Rezai et al(2012) was followed. Microbial characteristics were performed according to the standard microbial milk and dairy products number 2406. The color analysis was performed based on Hosseini et al (2019) method. The parameters of color include L* (lightness), a* (redness) and b* (yellowness) were measured. The sensory attributes were evaluated by 9 panelists. A five-point hedonic scale rating (1= very bad, 2=bad, 3= neither bad nor good, 4= good, 5= very good) was carried out. Data analyzed with SPSS: 22 software and Means were compared with Duncan multiple range test (p<0.05).

    Results and Discussion

    The analysis of black cumin essential oil with GC/MS chromatography showed that the main ingredients of it were α-Thujene, p-Cymene, Linalool, Thymoquinone, Carvacrol and Longifolene. The results showed that Changes in essential oil percentage had significant effect (p<0.05) on acidity, pH, IC50. With increasing essential oil percentage, an increase in the level of acidity and decrease in the level of IC50 and pH was observed. Changes in essential oil percentage had no significant effect(p<0.05) on protein, fat, salt and dry matter content of cheese. The results showed that storage period had no significant effect (p<0.05) on protein, fat and salt content. Increasing the essential oil percentage of cheese significantly decreased the L* index and increased the b* index. The microbial analyses showed no microbial contamination (coliforms, sataphylococcus aureus, mold and yeast) was found during the storage time therefore, the essential oil of Cumin can be used as a natural preservative in cheese production. Analyses of the sensory characteristics during storage time showed that the addition of essential oil to cheese did not have any significant effect on color and texture but had a significant effect on taste and acceptance of cheese. In all treatments, the taste score changed significantly with time (p <0.05). Over time, the flavour rating began to increase until the twentieth day, and then decreased to the end of the storage time. In general, the treatment containing 0.05% Black Cumin essential oil has the highest acceptance in sensory evaluation and since its other characteristics were standard, it was selected as the best treatment.

    Keywords: Black Cumin, cheese, essential oil, physicochemical, microbial
  • Mitra Mansouri Bani, Vahid Samavati, Marzieh Bolandi* Pages 423-435
    Introduction

    The Cholesterol in our diet is a risk factor for the prevalence of cardiovascular diseases. One of the effective ways to reduce the incidence of such diseases is to remove cholesterol, including animal fats, from our food sources. In this research, attempts were made to investigate the effect of operational factors on reducing cholesterol in cream by beta-cyclodextrin using RSM and to examine its physicochemical properties. The variables in this study were beta-cyclodextrin concentration, mixing temperature and mixing time.

    Materials and Methods

    The 3.5% fat raw milk was pasteurized at 72°C for 16 s, and then it was cooled to 55°C. The milk cream was separated by a separator and adjusted to 36% fat. Beta-cyclodextrin was added in 0.5, 1, 1.5% concentration in water bath at three levels of 10, 30, 50 ° C. It was mixed at three time intervals of 5, 15, 25, min. Cream containing beta-cyclodextrin was centrifuged to eliminate the complex formed in different periods and the beta-cyclodextrin and cholesterol complex was isolated. Beta-cyclodextrin of 99.2% purity was purchased from Sigma-Aldrich and all chemical agents from Merk, Germany. To measure cholesterol content in the preparation phase, hexane and ethanolic solution of potassium hydroxide (Merk) and the standard solution of cholesterol (Merk) were used. To determine the level of cholesterol in the samples, Lee et al. (1999) method was used after a few modifications. Firstly, cholesterol was extracted from the specimens and the cholesterol levels in the samples were determined with a chromatography apparatus equipped with flame ionization. The quantitative measurement of cholesterol was conducted by comparing the peak areas with a response from the internal standard. The experiments were designed, using the response surface method and the Box-Behnken Design (BBD), to achieve a high-efficiency process in reducing the highest cholesterol level and determining optimum conditions. The viscosity was determined using a Brookfield viscometer, and the over run and foam stability of the cholesterol cream samples were determined using a Graduated cylinder.

    Results and discussion

    Due to the cavity in the central part of beta-cyclodextrin molecular arrangement, it can form a stable cholesterol-insoluble complex and help to isolate it from the product. The results showed that time, mixing temperature, and beta-cyclodextrin concentration all had a positive effect on reducing the level of cholesterol, and the effect of independent factors was almost the same, as the time factor had the highest effect, supported in Makoto et al. (1999). Concentration factor had the least effect on cholesterol reduction, contrary to studies by Aryafar et al. (2007) and Yen et al. (1995). Among the interactions of the investigated factors, the highest effect was due to the simultaneous effects of temperature and time (88.9%) and the least effect was due to the simultaneous effect of concentration and temperature (85.5%). Findings of this study showed that the use of beta-cyclodextrin resulted in a successful reduction of cholesterol from the product without affecting tissue properties, increasing viscosity and volume, or reducing stability of the foam. The absorption of cholesterol by beta-cyclosporine depends on its concentration. The mixing time and temperature also boosts the effect. After examining the effects of each independent variable, it can be concluded that all three investigated variables have an incremental effect on the level of cholesterol in the evaluated levels. Increasing mixing time has the highest effect on increasing cholesterol and increasing the concentration of beta-cyclodextrin has the lowest effect on cholesterol reduction. Investigating the interaction effects of variables also showed that the simultaneous effect of temperature and time with the proper concentration of beta-cyclodextrin could have a significant effect on cholesterol reduction. The response surface method and Box-Behnken Design as statistical optimization and modeling techniques enabled the researchers to predict the optimal conditions for maximal removal of cholesterol by beta-cyclodextrin at the decided levels. The optimal operating condition obtained by the model for 36% fat cream contains 42.1% beta-cyclodextrin concentration, 76.75 ° C temperature and 87.83 min of mixing time. The predicted cholesterol reduction in these conditions was 89.92%, which was very close to the experimental value obtained in predicted optimal conditions. It indicates the accuracy and predictive power of the intended model.

    Keywords: beta cyclodextrin, cream, cholestrol, optimization, Response Surface Method
  • fatemh Eivani, behzad nasehi*, Mohammad Noshad, Hasan Barzegar Pages 437-452
    Introduction

    Increasing the demand for purchase and use of high quality products with good health benefits has led to a lot of efforts to increase and maintain the quality of different products. Sponge cake is one of the cereal products that the stale and lack of dietary fiber in cake flour is one of the major problems in this product. Cake is one of the flour mills and is intermediate in terms of calorie content of bread and biscuits. This high-consumption product has many fans among children and adolescents. Given the fact that this group of people is in the age of growth and healthy and nutritious nutrition will play a significant role in their health, the enrichment of all kinds of cakes is among the most important issues. Since the predominant promise is low-value and even unattractive and with high calories, it only causes obesity and cardiovascular disease. Recently, the use of fruit and vegetable waste has become widespread to reduce environmental pollution. Considering that these lesions are important sources of polyphenols. Industrial and agricultural residues are sources of natural antioxidants and food fibers. The functional properties of some skin components, such as pectin, flavonoids, carotenoids, lemonies, and poly-methoxyflavones, should be taken into account. Nowadays, cake producers have a major problem with lipid oxidation, which limits the shelf life of their products. Bakery products such as cakes, especially those with high fat content, tend to become corrosive after prolonged storage due to unsaturated fatty acids. Special attention has been paid to the use of natural antioxidants to minimize the use of synthetic additives. In recent years, the growing trend of bakeries with nutritional value such as rich fiber has been observed. In order to increase fiber content in cake and muffins, several raw materials such as bran, outer layers of grains have been used.

    Materials and methods

    Pomegranate was purchased freshly from the market, then the seeds were separated, then the samples were dewatered and the cores were dried at 30 ° C for 2 days. The pomegranate cores were dried after milling and after passing the sieve with the mesh 35 was used. The dough was prepared and the pomegranate and xanthan gum flour was added to the dough. The prepared dough was poured into the mold, then the molds were bake for 30 minutes in an oven at 175 ° C. Cakes were then stored after leaving the oven and cooled in polyethylene packages at room temperature until further tests were performed. An image processing method was used to check the porosity and color of the crust and crumb of enriched cakes. For this purpose, the imaging was carried out in a special box with a uniform white light at all directions and from a fixed distance with the Canon Power Shot P500 Canon Camera. Pictures are saved in JPG format. To get the same levels from each image, Adobe Photoshop CS4 (Photoshop CS6) was designed with 457 x 504 pixels for the brain and skin. To colorize the samples, the RGB color space was converted by Image J software to * L,*a, and *b. In this research, the effect of replacing wheat flour with pomegranate powder (0-50%) and xanthan gum (0 to 0.3%) on the physico-chemical (Moisture, pH, ash, porosity, volume index, fiber and protein), qualitative (Density, stiffness, weight loss, symmetry, volume, color and durability) and sensory properties of cake were evaluated using the response surface method in the form of a composite design.

    Results and discussion

    The results of this study showed that increasing the replacement of pomegranate powder has a positive and significant effect on fiber content, protein and weight loss and negative effect on density properties, texture stiffness, symmetry, volume index, color indices, the overall acceptance and flavor of the samples. Also, increase in the percentage of xanthan gum has a positive and significant effect on density, texture stiffness, volume, porosity, and volume index and weight loss of samples. In general, the evaluation of all characteristics showed that the cake sample containing 0.1% gum and 22.22% pomegranate powder had the best quality. On the other hand, comparing the optimal sample and the control indicates that the replacement of pomegranate powder has increased the phenolic compounds and reduced peroxide value.

    Keywords: Pomegranate seed, Functional, Dietary fiber, Sponge Cake
  • Sharareh Rezaeian, HamidReza Pourianfar, Shadi Bolourian, Hamed Saberian* Pages 453-464
    Introduction

    At the present, culinary-medicinal mushroom Enoki, Flammulina velutipes, ranks fifth among cultivated mushrooms in the world. Enoki has a delightfully crunchy texture and desirable taste. In addition, research has proved that this mushroom possesses substantial nutritional and medicinal properties. However, commercialization of Enoki is not yet expanded worldwide and it is still largely behind the other major edible mushrooms in some countries in west Asia (such as Iran). Based on our recent successful study on cultivation of Enoki in locally available lignocellulosic substrates, this study was aimed to evaluate the possibility of production of a novel functional drink based on Enoki mushroom supplemented with curcumin.

    Materials and Methods

    A pure culture of the cultivated strain of Enoki was freshly fructified in a locally available lignocellulosic substrate composed of 40 % wheat straw + 40 % sawdust + 18 % wheat bran + 1 % lime + 1 % gypsum. The fresh fruiting bodies were crushed to different forms of pulp and puree to be utilized in the basic formulation of drink. Then, different concentrations of mushroom particles (5, 7.5 and 10 %) and pectin gum (0.05, 0.075 and 0.10 %) were used. Following pasteurization at 90 ºC for one minute, the rheological and sensory characteristics of the drink were evaluated. The viscosity and the flow behavior of the samples were measured at 7°C. A rotational programmable viscometer (LVDV-II Pro, Brookfield Engineering Inc., USA) with an LV spindle was employed. About 25 ml of each drink was poured into the cylinder of the viscometer and shear rate was measured from 5 to 200 s−1 within 5 s intervals. Effect of different treatments (pectin gum and mushroom concentration) on color indices of the Enoki drink was studied using colorimeter (ColorFlex EZ, Hunter Lab, USA) and indices of, L* (brightness), a* (redness–greenness), b* (yellowness–blueness), were determined. Some sensory characteristics (taste, odor, color, mouth feel, consistency, particle concentration and overall acceptance) of the Enoki drinks were evaluated by 12 trained panelists (aged 25–50 years) using a 5 level hedonic test (1, 2, 3, 4 and 5) from left to right representing unacceptable, relatively acceptable, good, very good, and excellent. Three types of flavor (Lime, tropical fruits and apple) were employed and the effect of the flavors on odor, flavor, taste and overall acceptance of the pulp- based drink was investigated. Finally, three concentrations of curcumin (0.01, 0.03 and 0.05 %), as a natural colorant, were used in the pulp- based drink and the overall acceptance of the panelists was evaluated in a separate test. Factorial tests based on the completely randomized design was employed to evaluate the effect of different concentration of mushroom and pectin gum. Results were analyzed by analysis of variance (ANOVA) using SPSS 19 statistical software and the Duncan’s test with 95% confidence interval was used to compare the means of the tests. The results which were presented in this research have been obtained from the average values of 12 replicates.

    Results and Discussion

    Rheological tests showed that the flow behavior of the drink was pseudoplastic (or shear thinning), which indicated that the viscosity was decreased when the shear rate increased. All the samples had a yield stress at 7°C. Therefore, all the drink samples had a jelly form before exerting any stress, while the mushroom particles were completely suspended in the drink. From the panelists’ point of view, there was not any difference between the color of the drink containing different gum and mushroom, but L*, a* and b* values were significantly different. By increasing of the gum and mushroom concentration, brightness index (L*) increased. Sensory tests indicated that the highest and the lowest scores of flavor were related to samples containing 5 and 10 % (w/w) mushroom, respectively (p<0.05). Finally, the drink containing 5% mushroom puree and 0.05 % pectin gum was selected. The results of sensory evaluation showed that the drink containing mushroom pulp was significantly better than one containing mushroom puree (p<0.05). The overall acceptance of the Enoki drink containing lime flavor was the highest and there were not any significant differences between those containing apple and tropical fruits flavor. Furthermore, sensory acceptance of the drink increased by adding 0.05 % curcumin into it. It can be concluded that the drink containing Enoki mushroom pulp may have a good potential to be accepted by consumers. The use of a culinary-medicinal mushroom such as Enoki along with a natural colorant (curcumin) may make the drink a functional food without having any side effect. Overall, the findings of this study showed that the industrial production of this novel functional drink, with acidic lime taste and curcumin colorant, is feasible from a technical point of view.

    Keywords: Enoki mushroom, Curcumin, Functional drink, Physicochemical properties
  • Zohreh Bor bor moradi, Leila Nateghi*, Orang Eivaz zadeh Pages 465-478
    Introduction

    Flour products are one of the most widely used food products in all over the world. Various types of pastry products derived from wheat flour are including the varieties of soup, plumura, and cane produced by traditional and semi-industrial methods. They are categorized in the bread and cereal group. The place of wheat- flour dough products, including Ashi noodle in the food basket of Iranian households, is gradually being consolidated. This product is a mixture of wheat flour, water and salt after the treatment process by the machine before being dried. The high consumption of salt in the Ashi noodle leads to the development and progression of hypertension in addition to increasing the risk of cardiovascular disease and, on the other hand, reducing salt leads to problems such as loosening and loss of Ashi noodle drying, as well as the degradation of the strand when boiling. Hydrocolloids or gums are compounds creating consistency and texture and increasing stability, acting as emulsifiers, forming gels, and improving oral sensation.

    Materials and methods

    The general objective of this study was to investigate the effects of adding Farsi gum extract at concentrations of 0.2, 0.4, 0.6, 0.8, 1 and 1.2% based on the weight of flour instead of the salt used in the control group of the Ashi noodle (4.5%) on the rheological properties of Ashi noodle, as well as the evaluating physicochemical, texture, colorimetric, qualitative and sensory properties of low salt Ashi noodle one day after production. Zedo gum is a clear gum leaked from mountain almond trees. Zedo gum is found in white, light yellow, yellow vegetable, orange yellow, red and brown, in various sizes and forms. This gum is also composed of Arabinose and Galactose units. It is also known as Shirazi gum. Therefore, seven treatment groups and a control group were designed according to a completely randomized design. In order to analyze the data, Duncan’s method was used at 95% significance level in mini-fever software.

    Results and discussion

    The results of rheological tests of dough with aloe vera revealed that salt reduction and increased gum significantly (p≤0.05). Those rheological properties of the aqueous pulp which were influenced were including mean curve height, mean curve length, inflation index, and mean surface under the curve, configuration test, and elasticity. The physicochemical results showed that by adding gum and reducing salt content. The amount of moisture was increased and the amount of ash and salt decreased significantly. The results of texture test were determined by texture analysis analyzer. By reducing salt, increasing the concentration of gum, and the hardness of the treatments, the decreasing trend and adhesion rate increased, with the highest adhesion ratio for gum samples 1 and 2. There was no statistically significant difference in the level of adhesion, elasticity and gumminess. The results of colorimetric tests with Hunter lab showed that there was no statistically significant difference in the color components a*, b⃰ and L* between all treatments with the control sample. In evaluating the qualitative characteristics of Ashi noodle, it was shown that by reducing the amount of salt to 3.90% and adding gum to the concentration of 0.6% of the weight of the heterogeneous strands, the weight of the broken and degraded strands showed a decreasing trend compared to the control; and in the concentrations higher than 0.6% gum, these incremental changes showed a statistically significant difference between the samples with 1.2% gum and the other treatments. Moreover, the results of sensory evaluation indicated that there was no significant difference compared to the control sample by reducing the amount of salt to 3.90% and adding 0.6% gum to smell, color, texture and overall acceptance of treatments. The taste score of all treatments did not differ significantly from the control sample. The results of this study showed that the amount of Ashi noodle salinity could be reduced to 0.6%, and instead, gum can be added to it with no effect on the qualitative, textural and sensory properties of the Ashi noodle compared to the control sample.

    Keywords: ashi noodle, Zedo Gum, low salt, Alveolab, Texture profile analysis
  • Faezeh Jamalizadeh, Mahdi Ghasemi varnamkhasti*, Mahdi Ghasemi Nafchi, Mojtaba Tohidi, Majid Dowlati Pages 479-491
    Introduction

    Spices are the most valuable medicinal plants used in food and medical science industries and due to quality and price diversity between various species, distinction, classification and separation of them based on purity and quality degree have great importance. Spices are produced in different countries, including India, Pakistan, China, and East and South Asian countries. The difference in the percentage of aromatic compounds in various types of spices from different regions has led to a distinction between spices. Also, profitable individuals for economic purposes and more profit without regard to the general health of the community will lead to the creation of adulteration in different types of spices. The most important of these adulterations is the addition of volatile ingredients such as cubeb pepper and palm kernel powder in black pepper.

    Materials and Methods

    In this study, an olfactory machine system based on eight metal oxide semiconductor sensors in combination with pattern recognition methods were used to classify and separate of black pepper samples based on geographic origin and also to detect cubeb pepper adulteration and palm kernel powder. The adulterated black pepper samples were tested with different adulteration levels (10, 20 and 30%).The fractional method was used to improve and optimize the electronic nose output signals before entering diagnostic methods. In order to analyze the extracted data from the sensor response signal, the principal component analysis method (PCA) was used. Based on the results, PCA with two main components of 96% for black pepper and 95% of cubeb pepper and palm kernel adulteration can be described from the variance of data. Also, three methods of linear separation analysis (LDA), Support vector machine (SVM) and decision tree (DT) were used to classify the samples. The use of the LDA method for black pepper showed a classification precision of 100%, and for adulterations, accuracy was 97.14%.

    Results and Discussion

    The results showed that SVM with Gaussian function has the highest accuracy in classifying black pepper samples, cubeb pepper, and palm kernel adulteration Also, the success rate of the DT method in separating and categorizing black pepper, cubeb pepper, and palm kernel was 96.66% and 88.5%  respectively.According to the results obtained, the machine olfaction system in combination with pattern recognition methods has the ability to detect and classify different black pepper samples from different geographical origin and the lowest level of adulteration.

    Keywords: Nose electronics, Black pepper, Cubeb pepper, Palm kernel
  • Soheil Reyhani Pool, Ali Jafarpour* Pages 493-505
    Introduction

    Following extensive research on antibacterial and antioxidant properties of chitosan and hydrolyzed proteins and their satisfactory results, the use of these compounds as natural preservatives and good alternative to antibacterials and synthetic antioxidants in various nutrients is essential. The aim of the present study was to investigate the properties of chitosan coating containing FPH in the preservation of rainbow trout (Oncorhynchus mykiss) fillets at refrigerated temperatures.

    Materials and methods

    The hydrolyzed protein powder (FPH) used in this study was produced by enzymatic hydrolysis of frame (skeleton with the meat attached to it) of common carp (Cyprinus carpio) with flavourzyme enzyme. Accordingly, this powder was added to the chitosan coating (2% w/v chitosan + 2% w/v FPH). In order to investigate antibacterial and antioxidant properties of chitosan coating containing FPH, rainbow trout fillets were coated with chitosan (treatment 2) and chitosan containing FPH (treatment 3). Then, these sample treatments and control (treatment 1) were subjected to chemical (PV, TVN-B, TBA, FFA and pH) and microbial (count of aerobic mesophilic and psychrophilic bacteria) tests on days 0, 4, 8, 12, 16 and 20 in refrigerated storage. This study was implemented in form of completely randomized design and data were analyzed by one-way ANOVA and significant differences between the means were tested by Duncan's test at 95 confidence level.

    Results and discussion

    According to the chemical tests, TBA, TVN-B and FFA indices showed an increasing value during the refrigeration period significantly (P<0.05) while their trend was lower in treatment 3 compared to the treatments 1 and 2. TBA index for treatments 1, 2 and 3 in day 0 was 0.017, 0.015 and 0.014 mg MDA/kg fillet respectively that this amounts reached to 1.49, 0.99 and 0.52 mg MDA/kg in day 20. At the beginning of the preservation period, TVN-B index was calculated 13.36, 13.18 and 12.46 mgN/100gr fillet for treatments 1, 2 and 3, respectively. But these values changed to 43.36, 30.19 and 22.11 mgN/100gr fillet for mentioned treatments at the end of preservation period. FFA index was 0.16, 0.14 and 0.12 percentage of oleic acid for treatments 1, 2 and 3 in day 0 whereas after 20 days of storage, this index increased to 2.55, 1.76 and 0.98 percentage of oleic acid for mentioned treatments respectively. The PV index was significantly less in treatment 3 compared to the treatments 1 and 2 in days 12, 16 and 20 (2.72, 4.42 and 4.12 meq o2/kg lipid respectively) but continuous incremental trend was not recorded in this index with increasing preservation time, even the end of the experimental period (day 20), the index decreased in all of treatments compared to the 16th day. The results of pH changes showed the stability of this index in treatment 3 during the preservation period (pH~6.30). Meanwhile, in day 12, 16 and 20, the pH of treatment 3 was significantly less than treatments 1 and 2 (p<0.05). The bacterial load count of aerobic mesophilic and psychrophilic bacteria in treatments (while having an increasing trend during the preservation period) showed that in day 8, 12, 16 and 20, the bacterial levels of treatment 3 were significantly less than treatments 1 and 2 (p<0.05). In this study, adding FPH produced from common carp fish (with degree of hydrolysis 15.9%) to chitosan resulted in enhanced antioxidant and antibacterial properties of chitosan coating. So that, the film obtained from the combination of chitosan and FPH was much stronger barrier against lipids oxidation and bacterial proliferation in rainbow trout fillets (at refrigerated temperatures) than pure chitosan film.

    Keywords: FPH, Chitosan, Antibacterial properties, Antioxidant properties