فهرست مطالب

پژوهش های صنایع غذایی - سال سی و دوم شماره 2 (تابستان 1401)
  • سال سی و دوم شماره 2 (تابستان 1401)
  • تاریخ انتشار: 1401/02/05
  • تعداد عناوین: 10
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  • لاله رومیانی*، طیبه غرغاوی صفحات 1-14
    زمینه مطالعاتی

    فیلم خوراکی پروتیین آب پنیر غنی شده با اسانس گیاهی می تواند کیفیت میگوی وانامی را بهبود ببخشد.

    هدف

    هدف از مطالعه حاضر بررسی تاثیر پوشش خوراکی آب پنیر به تنهایی و در ترکیب با اسانس های آویشن شیرازی (زاتاریا مولتی فلورا) و پونه کوهی (اورگانوم ولگارا) بر زمان ماندگاری میگوی وانامی که به روش اتمسفر تغییر یافته در جعبه های پلی پروپیلنی بسته بندی شده طی 16 روز در دمای یخچال نگهداری شدند.

    روش کار

    پارامترهای مورد بررسی شامل پراکسید، TVB-N، TBA و بار میکروبی، در روزهای 0، 4، 8، 12 و 16 اندازه گیری شدند. تیمارهای مورد بررسی شامل تیمار شاهد، تیمار 1 (پوشش خوراکی آب پنیر)، تیمار 2 (پوشش خوراکی آب پنیر به همراه 1 درصد اسانس پونه کوهی)، تیمار 3 (پوشش خوراکی آب پنیر به همراه 1 درصد اسانس آویشن شیرازی)، تیمار 4 (پوشش خوراکی آب پنیر به همراه 3 درصد اسانس پونه کوهی)، تیمار 5 (پوشش خوراکی آب پنیر به همراه 3 درصد اسانس آویشن شیرازی) بودند.

    نتایج

    در تمام تیمارها آب پنیر به میزان 10 درصد وزنی - وزنی استفاده شد. در مورد شاخص پراکسید، TBA وTVB-N تیمارهای شاهد و 1 بالاترین مقدار و تیمارهای 4 و 5 کمترین میزان را نشان دادند (05/0>p). تیمار شاهد بالاترین بار میکروبی را داشت و با افزایش سطح اسانس بار میکروبی به شکل معنی داری کاهش یافت و کمترین بار میکروبی مربوط به تیمارهای 4 و 5 بود. افزودن اسانس های گیاهی در دو سطح 1 و 3 درصد سبب افزایش زمان نگهداری میگو در شرایط دمایی یخچال شد و براساس استانداردهای TVB-N و میکروبی 4 تیمار دارای اسانس تا روز هشتم و دو تیمار شاهد و تیمار آب پنیر تا روز چهارم برای مصرف انسان مناسب بودند.

    نتیجه گیری نهایی

    استفاده از پوشش خوراکی آب پنیر همراه با سطوح 1 و 3 درصد اسانس آویشن شیرازی و پونه کوهی، ماندگاری میگو را به مدت چهار روز در مقایسه با تیمار شاهد افزایش داد.

    کلیدواژگان: پوشش خوراکی، کیفیت میکروبی، کیفیت شیمیایی، لیتوپنئوس وانامی
  • مانیا صالحی فر*، رمضان اکبری، لیدا شاهسونی مجرد صفحات 15-30

    غلات از اولین غذاهای شناخته شده بشر بوده که از زمان های بسیا کهن تاکنون همواره نقش بسیار مهمی در اقتصاد و تغذیه مردم دنیا به ویژه در کشورهای در حال توسعه داشته است. دونات یکی از محصولات تخمیری ویک اسنک سرخ کردنی ومحصولی پر مصرف در جهان به شمار می آید. کیفیت دونات سرخ شده به ظاهر(رنگ ، شکل و درخشندگی)، عطر وطعم، بافت و ارزش تغذیه ای بستگی دارد. اکسیداسیون روغن ها وچربی ها در فرآورده های غذایی حاوی روغن منجر به کاهش ارزش تغذیه ای و ویژ گی های این فرآورده ها می گردد. یکی از راه های جلوگیری از اکسیداسیون روغن ها وچربی ها افزودن آنتی اکسیدان ها است. مستعد بودن چربی به اکسیداسیون یکی از مهمترین دلایل پیدایش بوی تعفن، طعم نامطلوب و تغییرات رنگ در محصول است استفاده از آنتی اکسیدان مناسب در به تاخیر انداختن اکسیداسیون و بالا بردن عمر انباری محصولات غذایی موثر است. در این پژوهش اثر افزودن مقادیر مختلف پودر دانه خرفه (15،0%، 20%، 25%) واسانس دارچین(ppm 0،500،600) در محصول دونات مورد استفاده قرار گرفت. نتایج نشان داد که با افزودن پودر دانه خرفه و اسانس دارچین به آرد نول مقدار پروتیین، چربی و فیبرو همچنین پایداری خمیر افزایش ومقدار رطوبت و درجه سست شدگی خمیر کاهش یافت و میزان فیبرکل در محصول دونات افزایش یافت. ضمنا بافت محصول متراکم تر ورنگ آن تیره تر شد در مجموع به نظر می رسد با توجه به نتایج به دست آمده بهترین ترکیب در ویژگی های مختلف دونات، نمونه حاوی 15% پودر دانه خرفه و 600 PPM اسانس دارچین می باشد.

    کلیدواژگان: دونات، خرفه، اسانس دارچین، ویژگی های شیمیایی
  • بابک کرمی*، المیرا حاجیها، محمد کاظمیان صفحات 31-42
    زمینه مطالعاتی

    انجماد تنها روش نگهداری مواد غذایی میباشد که تغییرات ایجاد شده در بافت آبزیان را به حداقل میرساند. بنابراین نگهداری محصول در حالت منجمد یک روش مطمین برای عملآوری آبزیان دریایی میباشد.

    هدف

    این مطالعه به منظور ارزیابی تاثیر روش های مختلف انجمادزدایی (دمای محیط، مایکروویو و یخچال) روی فیله ماهی کفال طلایی (Liza aurata) منجمد انجام شد.

    روش کار

    در این تحقیق، ابتدا فیله کفال طلایی در دمای 35 - درجه سلسیوس منجمد و سپس به مدت 60 روز در دمای 18- درجه سلسیوس نگهداری شده و تاثیر روش های مختلف انجمادزدایی شامل انجمادزدایی در دlhd محیط (21 درجه سلسیوس)، مایکروویو (8 درجه سلسیوس) و در دمای یخچال (4 درجه سلسیوس) بر میزان ارزش غذایی و شاخصهای کیفی آن مورد بررسی قرار گرفت. مدت زمان انجمادزدایی در دمای محیط 1 ساعت، دمای مایکروویو 3 دقیقه و در دمای یخچال به مدت 8 ساعت به طول انجامید.

    نتایج

    نتایج حاکی از آن بود که از نظر میزان کاهش اکسیداسیون ثانویه (تیوباربیتوریک اسید) و مواد ازته فرار، پایینترین مقادیر شاخصهای شیمیایی مربوط به تیمار انجمادزدایی شده در دمای یخچال بود و داده های آن با دو روش دیگر اختلاف معنیدار داشت (05/0<p). کمترین مقدار pH در تیمار انجمادزدایی شده در دمای مایکروویو مشاهده شد. از نظر حفظ کیفیت ارزش غذایی ماهی (درصد پروتیین، چربی و حفظ رطوبت) روش انجماد زدایی در دمای یخچال و دمای محیط بهتر از دمای مایکروویو بود (05/0<p). همچنین از نظر شاخصهای رنگی، به جز شاخص روشنایی، فیله های انجمادزدایی شده در دمای محیط از کیفیت و مقبولیت بالاتری نسبت به دو تیمار دیگر برخوردار بودند.

    نتیجه گیری نهایی

    بر اساس نتایج حاصل از این تحقیق میتوان بیان کرد که انجمادزدایی آبزیان در دمای یخچال موجب حفظ ارزش غذایی ماده غذایی پس از انجمادزدایی خواهد شد. بنابراین، این روش مناسب ترین روش برای انجمادزدایی فیله کفال طلایی میباشد.

    کلیدواژگان: انجمادزدایی، تغییر کیفیت، ترکیبات شیمیایی، فیله کفال طلائی
  • نادیا دهقانی اشکذری، مریم قراچورلو*، پیمانه قاسمی افشار صفحات 43-57
    زمینه مطالعاتی

    روغن شترمرغ منبع روغنی بسیار با ارزشی است. با این وجود اطلاعات محدودی در مورد آن وجود دارد.

    هدف

    از این تحقیق بررسی ویژگی های فیزیکی و شیمیایی روغن استخراج شده از بخش های مختلف بدن شترمرغ و معرفی آن به عنوان منبع جدیدی از روغن خوراکی می باشد.

    روش کار

    در این تحقیق، از پیه موجود در 3 قسمت (جلوی قلب، جلوی قفسه سینه و زیرین شکمی) به منظور استخراج روغن با استفاده از روش گداخت مرطوب استفاده گردید. سپس برخی خصوصیات فیزیکی و شیمیایی روغن استخراجی از قبیل ترکیب اسیدهای چرب، کلسترول و استرول کل، ترکیبات توکوفرولی، نقطه ذوب، اندیس رفراکت، رنگ و زمان پایداری مورد بررسی قرار گرفت.

    نتایج

    عمده ترین اسیدهای چرب روغن های استخراجی، اسید اولییک بود. بیشترین میزان کلسترول (mg/100g 82/95)، استرول کل (mg/100g 91/125) و دلتاتوکوفرول (mg/100g 98/0)، در روغن جلوی قلب بود. بیشترین میزان آلفا توکوفرول (mg/100g 45/2) و بتا توکوفرول (mg/100g 87/0) در روغن جلوی سینه حاصل شد. نمونه ها با هم از نظر میزان گاما توکوفرول و گاما توکوترینول تفاوت معنی داری نداشتند. میزان نقطه ذوب و اندیس رفراکت، رنگ زرد و قرمز در روغن بخش جلوی قلب، جلوی سینه و بخش زیرین شکمی تفاوت معنی دار نشان ندادند. بیشترین میزان زمان پایداری نیز در روغن جلوی قلب حاصل شد.

    نتیجه گیری نهایی

    با توجه به نتایج به دست آمده، روغن شترمرغ به دلیل محتوای بالای اسیدهای چرب ضروری و ترکیبات توکوفرولی، میزان کم کلسترول و پایدا ری مناسب، می تواند به عنوان روغن با ارزش در صنعت غذا مدنظر قرار گیرد.

    کلیدواژگان: روغن، شتر مرغ، ویژگی های فیزیکی شیمیایی
  • فخرالدین صالحی*، محمدامین اسدنهال صفحات 59-71
    زمینه مطالعاتی

    سرخ کردن یکی از روش های تهیه محصولات غذایی از جمله بادمجان است که به دو روش سطحی و عمیق انجام می شود. استفاده از پوشش های خوراکی تهیه شده از صمغ ها در کاهش میزان جذب روغن طی فرآیند سرخ کردن عمیق محصولات غذایی سرخ شده موثر است. محصولات سرخ شده پوشش داده شده علاوه بر درصد پایین روغن، دارای ویژگی های حسی، ظاهری و بافتی بهتر، افت رطوبت کمتر و ارزش تغذیه ای بالاتری هستند.

    هدف

    در این تحقیق پوشش دار کردن برش های بادمجان با استفاده از پوشش خوراکی صمغ دانه مرو برای کاهش جذب روغن فرآورده مورد مطالعه قرار گرفت.

    روش کار

    در این پژوهش از غلظت های مختلف صمغ دانه مرو (0، 5/0، 1 و 5/1 درصد) جهت پوشش دهی برش های بادمجان هنگام سرخ شدن عمیق در دماهای 150، 175 و 200 درجه سلسیوس استفاده گردید و رابطه بین پارامترهای فرآیند و خصوصیات محصول نهایی به روش الگوریتم ژنتیک- شبکه عصبی مصنوعی مدل سازی گردید.

    نتایج

    نتایج این پژوهش نشان داد که پوشش دهی با صمغ دانه مرو باعث کاهش جذب روغن محصول نهایی شد. پیش تیمار پوشش دهی باعث حفظ رطوبت محصول نهایی شد و رطوبت نمونه پوشش داده شده با 5/1 درصد صمغ از سایر نمونه ها بیشتر بود. این فرآیند توسط روش الگوریتم ژنتیک- شبکه عصبی مصنوعی با 2 ورودی شامل غلظت صمغ دانه مرو و دمای سرخ کن و 5 خروجی شامل درصد روغن، مقدار رطوبت و سه شاخص اصلی رنگی (زردی (b*)، قرمزی (a*) و روشنایی (L*)) مدل سازی شد. نتایج مدل سازی نشان داد شبکه ای با تعداد 3 نرون در یک لایه پنهان و با استفاده از تابع فعال سازی سیگموییدی، توانایی لازم برای پیش بینی خصوصیات فیزیکوشیمیایی برش های سرخ شده بادمجان را دارد.

    نتیجه گیری نهایی

    نتایج آزمون آنالیز حساسیت نشان داد که تغییر غلظت صمغ دانه مرو بیشترین تاثیر را بر محتوای رطوبت و سپس بر روی مقدار روغن برش های بادمجان سرخ شده دارد. همچنین تغییر دمای سرخ کن نیز بیشترین تاثیر را بر شاخص روشنایی نمونه های سرخ شده داشت.

    کلیدواژگان: برش های بادمجان، پوشش دهی، تابع فعال سازی سیگموئیدی، سرخ کردن، صمغ دانه مرو
  • مریم عطایی، مریم خاکباز حشمتی*، جلال دهقان نیا، سعید داداشی صفحات 73-87
    زمینه مطالعاتی

    بروکلی منبع غنی مواد معدنی، تامین کننده ویتامین ها و منبع آنتی اکسیدان های طبیعی است. با توجه به فسادپذیری بالای بروکلی، جلوگیری از فساد آن برای حفظ ترکیبات زیست فعال حیاتی می باشد. خشک کردن روشی است که برای افزایش عمر ماندگاری محصولات غذایی کاربرد بسیاری دارد.

    هدف

    هدف از این پژوهش بررسی اثر روش خشک کردن (هوای داغ کنوکسیونی (CHA)، مایکروویو (MW)، هوای داغ-مایکروویو (CHA-MW)، مایکروویو-هوای داغ (MW-CHA)) بر پارامترهای سینتیک خشک کردن (محتوای و نسبت رطوبت، نرخ و زمان خشک کردن، ضریب انتشار موثر رطوبت و انرژی مصرفی) فوم پالپ کلم بروکلی است.

    روش کار

    فوم از 3 درصد (وزنی/وزنی) سفیده تخم مرغ به عنوان عامل فوم ساز و 5/0 درصد (وزنی/وزنی) محلول متیل سلولز به عنوان پایدارکننده کف تهیه شد. فوم بروکلی (ضخامت 5 میلی متر) با استفاده از روش های هوای داغ (دمای 40 درجه سانتی گراد و سرعت 1 متر بر ثانیه)، مایکروویو (90 وات)، مایکروویو-هوای داغ (MW-CHA) و هوای داغ-مایکروویو (CHA-MW) با همان دما و توان روش تکی، تا رسیدن به وزن ثابت خشک شد.

    نتایج

    ترکیب روش مایکروویو و هوای داغ (در هر دو شکل پیش تیمار و پس تیمار) نسبت به روش مایکروویو به تنهایی، موجب کاهش ضریب انتشار موثر و نرخ خشک کردن و افزایش انرژی مصرفی گردید. میانگین محتوا و نسبت رطوبت نیز تحت تاثیر روش خشک کردن و نحوه ترکیب مایکروویو و هوای داغ قرار گرفت؛ به این صورت که در روش خشک کردن مایکروویو-هوای داغ (MW-CHA)، میانگین محتوا و نسبت رطوبت در مقایسه با روش مایکروویو و هوای داغ به تنهایی، بیشتر بود اما میانگین محتوا و نسبت رطوبت در روش خشک کردن هوای داغ-مایکروویو (CHA-MW)، کمترین مقدار بین چهار روش دیگر را داشت.

    نتیجه گیری نهایی

    بر اساس کمترین میزان مصرف انرژی، زمان فرایند، میانگین محتوا و نسبت رطوبت و نیز بیشترین میزان ضریب انتشار موثر رطوبت و نرخ خشک شدن، روش مایکروویو با میزان مطلوبیت 88/0 و پس از آن روش CHA-MW با میزان مطلوبیت 7/0 روش بهینه برای خشک کردن فوم بروکلی شناخته شدند.

    کلیدواژگان: بروکلی، فوم مت، کنوکسیون، مایکروویو، هوای داغ
  • فرید بجایی، سید صادق سیدلو هریس، حبیبه نعلبندی*، حمیدرضا قاسم زاده صفحات 89-107
    زمینه مطالعاتی

    نان به دلیل تامین بخشی از کالری، پروتیین، ویتامین ها و مواد مورد نیاز بدن یکی از مهم ترین منابع غذایی مردم به ویژه در کشورهای در حال توسعه و توسعه نیافته است. در ایران 56 درصد از خانواده های روستایی، کالری خود را از نان، آن هم به صورت نان مسطح و نازک دریافت می کنند و میانگین مصرف سرانه نان دو الی سه برابر میانگین مصرف جهانی است. بنابراین سلامت و کیفیت آن بسیار مهم می باشد. به دلیل کیفیت پایین پخت، سالانه مقادیر زیادی نان به صورت ضایعات از دسترس خارج می شود. عوامل موثر بر دور ریز شامل کیفیت آرد، تکنولوژی تولید نان و نحوه نگهداری محصول پس از تولید است.

    روش کار

    هدف از این مطالعه اصلاح تکنولوژی پخت صنعتی نان مسطح به منظور کاهش آلودگی محصول و نیز افزایش کیفیت نان می باشد. بنابراین یک دستگاه پخت نان دوار با حرارت غیر مستقیم ساخته شد. به طوری که شبیه سازی مبدل حرارتی ماشین متناسب با فضای پخت صورت گرفت و از نتایج آن برای بررسی نحوه و یکنواختی بردارهای سرعت جریان هوا در داخل مبدل و متناسب با آن در توزیع گرما روی خمیر موجود در بستر پخت استفاده شد. پس از حصول مناسب ترین طرح، نسبت به ساخت آن اقدام شد و در داخل ماشین پخت نصب گردید. آزمایش پخت نان با ماشین توسعه داده شده و نیز پخت با ماشین های متداول موجود، اجرا و یکنواختی محصول به همراه آزمون های حسی صورت گرفت.

    نتایج

    نتایج نشان داد که کیفیت نان های تولید شده با مبدل توسعه یافته شده نسبت به روش صنعتی موجود از امتیاز حسی کل 09/5 در مقابل 54/4 برخوردار بود. ضمن اینکه به دلیل عدم تماس شعله و گازهای حاصل از احتراق با بستر پخت و نان، آلودگی با بنزوپیرن نمی تواند در پخت به روش حرارت غیر مستقیم وجود داشته باشد.

    کلیدواژگان: آلودگی، انتقال ممنتوم، شبیه سازی رایانه ای، ماشین پخت، مبدل حرارتی
  • شهین زمردی*، الهام آذرپژوه، پروین شرایعی صفحات 109-121
    مقدمه

    اسانس پوست پرتقال که در صنایع مختلف به عنوان طعم دهنده استفاده می شود، به طور معمول دارای ثبات فیزیکی شیمیایی و حلالیت کمتری در آب است. در این تحقیق، تاثیر ریزپوشانی بر ویژگی های اسانس حاصل از پوست پرتقال رقم تامسون مورد بررسی قرار گرفت.

    مواد و روش ها

    ابتدا پوست پرتقال در دمای 35 درجه سلسیوس به مدت 19 دقیقه تحت فراصوت در فرکانس 20 کیلو هرتز، با شدت 60 درصد قرار گرفت و سپس توسط دستگاه کلونجر اسانس آن استخراج شد. اسانس استخراج شده با استفاده از محلول های تهیه شده از بتاسیکلودکسترین و کازیینات سدیم در غلظت های 5 و 10% در آب، به روش خشک کردن انجمادی ریزپوشانی شد. سپس راندمان تولید، رطوبت، اندازه قطر ذرات، دانسیته توده، دمای انتقال شیشه ای، ترکیبات فنلی و قدرت گیرندگی رادیکال آزاد، ریزساختار و سینیتیک پایداری ریزکپسول ها تعیین شد. نتایج با استفاده از طرح آماری کاملا تصادفی در 3 تکرار تجزیه شد. میانگین ها در سطح 05/0 با آزمون چند دامنه ای دانکن مقایسه شد.

    نتایج

    نتایج نشان داد که ویژگی های ریزکپسول های تهیه شده با دیواره بتاسیکلودکسترین به جز دانسیته توده بالاتر از ویژگی ریزکپسول های تهیه شده با دیواره کازینات سدیم بود (p<0.05). رطوبت و راندمان ریزکپسول ها با افزایش غلظت بتاسیکلودکسترین افزایش اما با افزایش غلظت کازینات سدیم کاهش یافت. با افزایش غلظت هر دو دیواره دانسیته توده افزایش و دمای انتقال شیشه ای و قدرت گیرندگی رادیکال آزاد کاهش یافت. نتایج حاصل از تعیین ریزساختار نشان داد که ریزکپسول های حاوی بتاسیکلودکسترین به شکل کروی، دارای تورفتگی و خلل و فرج زیاد و ریزکپسول های حاوی کازیینات سدیم دیواره ای نازک و یکنواخت بدون خلل و فرج بود. نتایج حاصل از بررسی پایداری ریزکپسول ها حاکی است که در طول نگهداری با افزایش رطوبت نسبی، مقدار DPPH افزایش و با افزایش دما از 4 تا 25 درجه سلسیوس کاهش یافت.

    نتیجه گیری

    ریزکپسول های اسانس تهیه شده با دیواره بتاسیکلودکسترین با غلظت 10 %، دارای خصوصیات فیزیکی-شیمیایی بهتری نسبت به سایر دیواره ها بودند.

    کلیدواژگان: اسانس، پسماند فرآوری، پوست پرتقال، ریزپوشانی
  • نوشین نوشیروانی*، هادی فصیحی صفحات 123-138
    زمینه مطالعاتی

    تهیه پوشش های خوراکی یکی از راهکارهای موثر در افزایش عمر ماندگاری میوه ها تلقی می شود.

    هدف

    هدف از این پژوهش تهیه پوشش های فعال بر پایه کربوکسی متیل سلولز حاوی اسانس های زنجبیل و مرزه در دو غلظت 250 و 1000 پی پی ام به منظور نگهداری خیار تازه بود.

    روش کار

    پوشش های فعال بر پایه کربوکسی متیل سلولز حاوی دو سطح 250 و 1000 پی پی ام از اسانس های مرزه و زنجبیل تهیه شده و اثر پوشش دهی بر برخی ویژگی های خیار تازه مانند افت وزن، pH، اسیدیته، مواد جامد محلول، رنگ، شمارش میکروبی و خواص حسی خیارهای پوشش دهی شده در طول دوره نگهداری 16 روزه در دمای °C 10 مورد بررسی قرار گرفت. خیارهای تازه بدون پوشش به عنوان نمونه شاهد در نظر گرفته شدند.

    نتایج

    بر اساس نتایج بدست آمده، استفاده از پوشش های فعال حاوی اسانس به طور معنی داری افت وزن و رشد میکروبی را در خیار کاهش داد. نتایج نشان داد که در تیمارهایی که از اسانس مرزه استفاده شد میزان فساد میکروبی میوه بیشتر کاهش یافت و موجب حفظ سفتی بافت میوه گردید. تیمارهای پوشش دهی شده بر اثر حفظ رطوبت میوه، افت وزن را بهتر کنترل نمود و موجب افزایش سفتی خیار نسبت به نمونه شاهد در هر مرحله از انبارداری گردید. میزان مواد جامد محلول، pH و اسیدیته کل در نمونه شاهد نسبت به نمونه های حاوی پوشش به دلیل بالا بودن سرعت فعالیت های متابولیک دستخوش تغییرات بیشتری شد.

    نتیجه گیری نهایی

    بر اساس نتایج بدست آمده استفاده از پوشش کربوکسی متیل سلولز حاوی اسانس مرزه در هر دو سطح 250 و 1000 پی پی ام به دلیل خواص ضد میکروبی بالا، باعث حفظ رنگ خیار و بهبود کیفیت میکروبی آن شده و ضمن کاهش میزان افت وزن، سفتی و خواص حسی مطلوب نمونه را نشان داد.

    کلیدواژگان: خیار، پوشش ضد میکروبی، کربوکسی متیل سلولز، اسانس مرزه، اسانس زنجبیل
  • محمد ابونجمی*، مریم گنجدوست، حسین میرسعیدقاضی، کیوان آصف پور وکیلیان صفحات 139-152
    زمینه مطالعاتی

    عمر انبارمانی قارچ دکمه ای (Agaricus bisporus)در دمای متوسط محیط، درصورتی که حداقل فرآوری را متحمل شده باشد به سبب قهوه ای شدن آنزیمی بین دو تا چهار روز است. در نتیجه، این محصول یکی از حساس ترین محصولات کشاورزی از نقطه نظر فیزیولوژی پس از برداشت می باشد.

    هدف

    این پژوهش به منظور بررسی استفاده از فراصوت قدرتی به تنهایی و به همراه تیمارهای دیگر مانند پراکسید هیدروژن و ازن جهت افزایش انبارمانی قارچ خوراکی میباشد.

    روش کار

    در پژوهش حاضر اثر تیمارهای مختلف بر بهبود ویژگی های فیزیکی و شیمیایی شامل وزن، pH، سفتی بافت، ماده جامد محلول، و بار میکروبی قارچ خوراکی مورد آزمون قرار گرفت.

    نتایج

    مقایسه نمونه ها در طول دوره ی انبارمانی بیانگر روند افزایشی در کاهش وزن نمونه ها بوده که مقدار کاهش وزن در نمونه ی کنترل به طور قابل توجهی بیشتر از نمونه های شستشو داده شده با فراصوت بود. همچنین نتایج نشان داد اگرچه تیمار ازن اثر معناداری بر نمونه ها نداشت، اما تیمارهای شستشو داده شده با فراصوت و پراکسید هیدروژن از نظر کنترل بار میکروبی دارای عملکرد بالایی نسبت به حالت کنترل و سایر تیمارهادر سطح 1% بود. با استفاده از این تیمار به مدت 6 دقیقه، بار میکروبی نمونه ها در طول 12 روز انبارمانی از 61 به cfu/g 5/87 افزایش یافت، در حالی که بار میکروبی نمونه های شاهد و دیگر تیمارها به طور معناداری بیشتر از این میزان بود.

    نتیجه گیری کلی

    بکارگیری همزمان تیمار فراصوت قدرتی و پراکسید هیدروژن در زمان اعمال 6 دقیقه می تواند یک روش مناسب برای افزایش انبارمانی قارچ دکمه ای تا 12 روز باشد.

    کلیدواژگان: انبارمانی، فراصوت قدرتی، قارچ خوراکی، پراکسید هیدروژن
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  • Laleh Roomiani *, Tayebeh Gharghavi Pages 1-14
    Introduction

    New fish are consumed worldwide as one of the most important nutritious foods. On the other hand, due to the high content of free amino acids and nitrogen in the tissues of the body, as compared to red meat or chickens, the rate of corruption is higher. The stages of aquatic corruption usually begin by removing the natural flavor and aroma that result from the growth of corrosive microorganisms. On the other hand, the structure of the tissue is lost and odor and corrosion can be detected. These entire changes make the shelf-life of aquatic animals, both in the form of packaging and non-closure, very limited. In addition to traditional methods used to extend the shelf-life of fish products, like MAP or chilling storage, there is an increasing interest in the use of edible films and coatings with antimicrobial properties in order to reduce, inhibit, or delay the growth of microorganism on the surface of foods. Edible films and coatings can be made of polysaccharides, proteins, and lipids and can act as carriers of different compounds like antioxidant, antimicrobials, and other preservatives in order to improve food quality and safety. Therefore, the use of composition, herbal essences and modified atmosphere as a different protective technology can be a solution to improve the microbial quality of the aquatic fillet, such as shrimp, as potentially having synergistic effects (Carrion-Granda 2015). The purpose of this study was to investigate the effect of using water-based coatings alone and in combination with Zataria multiflora and Origanum vulgare essential oils on the shelf life of the Litopenaeus vannamei shrimp in a 16-day period in closed polypropylene boxes was modified by atmospheric method (CO2-50% - N245% -O2 5%) at refrigerator temperature. Then, the objectives of this work were (1) to evaluate the effectiveness of whey protein isolate edible coatings enriched with essential oils on the microbiological quality of hake fillets and (2) to assess the combined effects of edible coatings and MAP on the microbiological quality of hake fillets stored under refrigeration conditions. Besides, the influence of initial fish microbial loads in the effectiveness of edible coatings and MAP over the quality of hake fillets was analyzed.

    Material and methods

    The plant was collected from Shirazi and Zanjan Mountains from Fars province and was examined by botanists of the Institute of Medicinal Plants of Jahad University of Tehran University. Experiments were carried out at Sari lab. The extraction was carried out according to the Nelson and Onyagaba method (2007). The 50 g dry leaves of the plant were first grinding and 500 ml of 95% ethanol was placed in a detonator. Essential oil was taken for 24 hours. The solvent was evaporated by rotary device. Whey protein or WPI (10% w / w) was dissolved in distilled water and 5% glycerol (w / w) was added due to its formability. The coated food coating solution (FFS) was heated to 90 ° C using a thermostatic bath and heated for 30 minutes. Oregano essential oils and Thymol Shirazi was added to it at 1 and 3% (w / w) and allowed to cool at room temperature. The edible coating solution was then homogenized using a series of 7 mm diameter series for 5 minutes and a range of 100%. During this time, the edible coating solution was stored in an ice-water bath to avoid rising temperatures and reaching 40 ° C. The parameters included peroxide, TVB-N, TBA and microbial load on days 0, 4, 8, 12 and 16. The treatments included control treatment, treatment 1(edible coating with whey), treatment 2 (edible coating with whey and 1% Origanum vulgare oil), treatment 3 (edible coating with whey and 1% essential oil of Zataria multiflora), Treatment 4 (edible coating with whey and 3% Origanum vulgare), treatment 5 (edible coating with whey and 3% essential oil of Zataria multiflora). Samples were packed in modified atmosphere (CO2 50% - N245% -O2 5%) and kept for 16 days. Both saw and all coated samples were packed in polypropylene boxes.

    Results and discussion

    In all treatments, whey was used at a weight of 10% by weight. In the case of peroxide, TBA and TVB-N, control treatments and 1 had the highest and 4 and 5 treatments had the least of these parameters (P <0.05). Control treatment had the highest microbial load, and with increasing level of essential oil, the microbial load significantly decreased (P <0.05) and the lowest microbial load was related to treatments 4 and 5. Adding herbal essential oils at two levels of 1 and 3% increased the duration of shrimp keeping in refrigerated temperatures and based on TVB-N and microbial standards, four treatments had essential oil until day 8 and two treatments were applied until the day 4 Suitable for human consumption.

    Conclusion

    food coatings are capable of replacing many types of polymer packages. The results of this study showed that the coating of whey without supplementing herbal essential oils of Thymol Shirazi and Oreganeh winter wheat did not have the necessary efficiency in increasing the shelf life of Thymol Shirazi and Oreganeh. Adding herbal essential oils at two levels of 1% and 3% increased the maintenance of shrimp in a refrigerated temperature. Based on TVB-N and microbial standards, four treatments had essential oil until day 8, two control treatments and whey treatment until day 4 Suitable for human consumption. In this way, the use of whey coating with 1 and 3% essential oils of Thymol Shirazi and oregano, improved the shrimp shelf life for 4 days compared with the control.

    Keywords: Edible coating, Antimicrobial activity, modified atmosphere packaging, microbial quality, chemical quality, Litopenaeus vannamei
  • Ramezan Akbari, Lida Shahsavani Mojarad Pages 15-30
    Introduction

    Cereals are one of the first known human foods that have long played an important role in the economics and nutrition of the world's people, especially in developing countries, since ancient times. One of the sweetest donut wheat products is the largest breakfast breakfast industry in the United States And after potato crops, it is the most consumed among all kinds of snacks (Zolfaghari 2010). The use of appropriate antioxidants is effective in delaying oxidation and extending the shelf life of food products. Consumers prefer natural antioxidants to their synthetic form. Among oilseeds, purslane is rich in omega-3 fatty acids (alpha-linoic acid) than other grains. Cinnamon is also one of the most important spice plants that has healing properties and has antimicrobial and nutritional properties in the food industry. It is used as an antioxidant and has an excellent flavor quality. Donut is a flour-based pastry made from frying fresh or fermented dough in oil and used as a pastry, dessert or dessert (National Iranian Standards Organization, National Standard No. 16980). In another study of the conquest of Kazemi et al., (2012), the effects of adding Purslane and Flaxseed Powdered Seeds and their mixtures alone in 5, 10, 15, 20% to wheat flour on the sensory and chemical properties of bread flour samples And fortified bread such as oil percentage, linolenic acid, tocopherols and peroxide number were studied. The results showed that with increasing grain powder percentage, linolenic acid content of flour and bread samples increased to 20% in flour and bread samples. Adding grain powder caused a significant change in the peroxide values of flour and bread samples. The highest amount of β + tocopherol was obtained in control and 20% purslane oil. In terms of sensory characteristics, the highest score of the final score was for the 10% of the purslane and the 5% of the flax.

    Material and methods

    The ingredients used along with purslane seed powder and cinnamon essential oil include wheat flour, sugar, oil, egg, water, salt, purslane, cinnamon, enhancer, yeast, which were all purchased from Karaj market. The chemicals and solvents of the German brand Merck were obtained from the Tehran market. In order to prepare donuts, wheat flour plus the purslane seed powder purchased from the Karaji perfumes were thoroughly blended according to the treatments. Then the cinnamon essential oils (purchased from Tabriz, made by Spanish Airlines) were completely blended according to the treatments (0, 15, 20, 25%) by weight. Then, cinnamon essential oil was added to flour and potato according to treatments (0, 500, 600 ppm). The frying temperature was set to 180 ° C and the samples were gently placed in the fryer chamber. The donuts were cooled to room temperature for 30 minutes after frying.

    Results and discussion

    According to the results, moisture content in the prepared treatments was reduced by adding cinnamon essential oil and flour. The reason for this increase is the hydrophilic nature of the pectin gum compounds found in the purslane seed powder. It also has a high percentage of fiber and a water retention capacity by the purslane that drains water. Protein content of the treatments increased with increasing amount of purslane flour and cinnamon essential oil. Since purslane flour and cinnamon essential oil are rich in protein content, adding it to donut flour increases the protein content of donut flour. The results showed that the percentage of fat increased with the addition of purslane flour and cinnamon essential oil. This is because the purslane grain is rich in linolenic acid, linoleic acid, palmitic acid, stearic acid and oleic acid, and the increase in fat in treatments containing 25% of purslane is due to the high amount of the same saturated fatty acids. The results show that increasing the purslane and cinnamon increased the fiber content in the treatments. All treatments showed an increase in the stability of the dough with the addition of purslane flour and cinnamon essential oil. This means that the valuable components of the purslane seed provide strong mobile connections with flour. The results showed that in all treatments due to addition of purslane flour, a decrease in the degree of loosening was observed. Addition of purslane flour showed an increase in pulp expansion time and valerimetric value. However, the addition of cinnamon essential oil at no level had any effect on these two indices. The reason for this increase is the tolerance of mixing of pulp with pulp, the concentration of gluten protein with fiber, as well as the reaction between fiber and gluten, which in turn affects the mixing properties. Increasing in the amount of Purslane seed oil and cinnamon essential oil in the treatments decreased the brightness index (index L) of the donuts and the red-green index (index a) significantly increased as well as the yellow-blue index (index b) The increase in the use of purslane flour decreased and the amount of cinnamon essential oil increased significantly. This is due to the addition of purslane seed powder, which reduces the brightness of the donut. By adding powdered purslane seed, the texture of the donuts becomes denser. The densest tissues in the donuts were obtained from 25% purslane flour treatment and 600 ppm essential oil both on the first day after baking and on the third day. The results showed that the amount of donut fiber was measured at three time points of 5, 15 and 30 days after production. The results of mean comparisons showed that the addition of purslane flour and cinnamon essential oil was added to the amount of donut fiber. The results showed that by adding flour and cinnamon powder, the results showed a decrease in all traits compared to the control treatment. The lowest score in terms of aroma, taste, porosity and softness was related to treatment of 25 in purslane flour and 600 ppm of cinnamon powder and the highest score was in non-consumption.

    Conclusion

    The results of these studies showed that purslane seed is a rich source of high nutritional value that can be used in donut production. Also, in the study of the use of purslane seed powder and cinnamon essence in donut formulation, the amount of protein, fat, fiber, pulp stability and total fiber content in donuts were increased compared to the control sample. Also, according to the results of the evaluation of the referees, samples containing 15% purslane powder and 600 ppm cinnamon essence were more acceptable.

    Keywords: Donuts, portulaca oleracea, cinnamon essential oil, chemical properties
  • Babak Karami *, Elmira Hajiha, Mohammad Kazemian Pages 31-42
    Introduction

    Aquatic products are becoming a vital dietary component in humans’ daily life, due to their high protein and low fat, especially rich in polyunsaturated fatty acids (omega-3 and omega-6). Golden grey mullet, Liza aurata, have a commercial value for fisheries, especially in internal waters. This species usually lives inshore, lagoons and estuaries, and rarely move into freshwater. Additionally, they are widely distributed in the Mediterranean Sea and the Black Sea, Atlantic coasts from the Azores and Madeira northward to the British Isles, and the southern coasts of Norway and Sweden. Many technologies have been used in the food industry to extend the shelf-life of fish for ease of transportation, such as freezing which is the most effective method to ensure food quality and safety. Consequently, the frozen fish should be thawed before further processing. Generally speaking, the quality of frozen food is highly associated with the thawing process. Improper thawing methods have caused unacceptable changes of the chemical and physical properties of frozen fish such as drip loss, enzymatic reaction, lipid and protein oxidation, and inhomogeneity. There are different thawing methods in foods reported, such as air thawing, water thawing, refrigerator thawing, microwave thawing, ultrasonic thawing, high-voltage electric field thawing, high-pressure thawing, and so on. However, each thawing method has its advantages and disadvantages. Therefore, it is necessary to explore a better thawing method that is beneficial for maintaining the quality of frozen fish. The purpose of this study was to evaluate the effects of different thawing methods on the chemical, microbial, sensory, and physical quality of goldfish fillets after thawing.

    Material and methods

    Twenty live L. aurata weighted 400± 30 g were purchased and were kept in powdered ice in a ratio of 1 to 1 in medium-sized tanks and immediately transferred to the laboratory of the National Center for Aquatic Processing Research. After arrival, the butterfly method was used to wash fishes, then their skin and internal organs were removed. Two back fillets removed from the back. Each fillet was individually packed in a polythene bag to prevent moisture loss and frozen in storage at-35°C and then maintained at -18 °C for 60 days. The fillets were randomly divided into three groups and thawed by different treatments as follows: thawing in the microwave (8°C), ambient temperature )21°C) and refrigerator temperature (4°C). The duration of thawing in each of the above conditions lasted 1 hour, 10 minutes, and 8h, respectively. The experiments were performed at the National Center for Aquatic Processing Research in Bandar Anzali (affiliated to the Iranian Fisheries Research Institute) and at the Food Industry Laboratory of the Azad University of North Tehran Branch in October and November 2016. To determine the approximate amount of protein, fat, moisture, and ash sampling was performed in zero phases (before freezing) and final stage (after 2-months storage) after thawing. For measuring some content of mullet fillets (such as TVB-N and TBA, pH, etc.), color assessment, and weight loss, sampling was done three times during 2-months storage (zero phase, after one month, and after two months). Moisture, ash and protein contents, TVB-N, and pH were measured. Also, fat content and TBA were determined. Moreover, the color assessment was done using a colorimeter (NR60CP Precision Colorimeter, 3nh, China). All experiments were performed in triplicates. The normality of obtained data was checked by Kolmogorov – Smirnov method. All data were presented as mean values ± standard error (SE), which were compared using one-way analysis of variance (ANOVA) following Duncan’s multiple range test. A P-value of less than 0.05 was considered significant. This study was done in the summer of 2018.

    Results and discussion

    The results indicated that the amount of thiobarbituric acid (TBAs) and volatile nitrogen (TVB-N) and pH were significantly different between treatments. The highest value of the first two parameters and the lowest pH was found in microwave thawing (p<0.05). Also, a significant increase in thiobarbituric acid levels was observed in all three thawing methods. This may indicate increasing the fat oxidation, which may be due to the release of oxidative enzymes and peroxidants from disintegrated cells due to freezing. Regarding the moisture content, crude protein, fat content, and ash content, the results showed that thawing in ambient temperature and refrigerator is better than that thawing in the microwave. It must be due to the formation of drip in the process of thawing and the solubility of ash and protein in drip. Also, it should be related to the high energy of microwaves which causes the removal of intermittent water from fish’s bodies. also, color indices showed that the thawing fillets at ambient temperature had higher quality than at refrigerator and microwave temperature treatment, except for L*, which is the highest in refrigerator temperature.

    Conclusion

    Based on the results of this research, it can be noted that the freezing of the aquatic environment at refrigerator temperature will maintain the nutritional value of the food after dehumidification, the most suitable method for the thawing of the fillet.

    Keywords: Decontamination, Quality change, Chemical composition, Fish fillet
  • Nadia Dehghani Askezari, Maryam Gharachorloo *, Peymaneh Ghasemi Afshar Pages 43-57
    Introduction

    The ostrich (Struthio canelus) is the largest and oldest bird in the world and belongs to the Ratite family, which is unable to fly and is adapted to living in hot areas and barren lands. Birds of this family are characterized by low-fat meat and low cholesterol. Ostrich oil makes up about 15% of their total body weight (Basuny et al., 2017) that is mainly composed of triglycerides and is free of phospholipids. Ostrich oil is a relatively new and very valuable source of animal fats, which in recent years has received special attention to the use of it in pharmaceutical and food industries. Today, ostrich oil is mostly used for health, cosmetic and also medicinal purposes. Little researches has been carried out on its use orally and there is no comprehensive information about the properties of adipose tissue oil in different parts of ostrich body. Therefore, the aim of this study was to investigate the physical and chemical properties of oil extracted from different parts of ostrich body and introduce it as a new source of edible fat.

    Materials and Methods

    In this study, adipose tissue from 3 parts (front of the heart, front of the chest and lower abdomen) were obtained from ostrich breeding farm (Karaj, Iran). Oil extraction was carried out according to wet melting method by using rotary evaporator at 80°C for 2 hrs. Then some physical and chemical properties of the extracted oil such as fatty acid composition, cholesterol and total sterol, tocopherol composition, melting point, refractive index, color and induction period were investigated. The fatty acid composition of oils was determined by employing a gas chromatograph equipped with a DEGS capillary column (60 m × 0.25 mm i.d.) and a flame ionization detector. Sterols and tocopherols were identified by gas chromatography and high performance liquid chromatography methods respectively. Refractive index of oils was determined by using a refractometer and color of samples were analysed by application of Lovibond. The induction period was performed on a Metrohm Rancimat apparatus model 743 at 110 °C with an air flow of 20 L/h. All the experiments and/or measurements were carried out in triplicate order. The data were statistically analyzed using the Statistical Analysis System software package on replicated test data. Analyses of variance were performed by application of an ANOVA procedure. Significant differences between the means were determined using the Duncan multiple range test.

    Results and discussion

    Based on the results, the highest amount of oil extracted from the abdominal parts (62.45%), front of the chest (40.35%) and front of the heart (38.58%) respectively. The main saturated and unsaturated fatty acids of extracted oils were palmitic and oleic acids respectively. The results of total saturated and unsaturated fatty acids in oil samples indicated that the highest amount of total saturated fatty acids was observed in oil obtained from the front of the heart (34.59%) and the lowest amount was observed in lower abdominal oil (33.72%) (P<0.05). The highest amount of unsaturated fatty acids was related to the lower abdomen oil (66.28%) and the lowest amount was in the front of the chest oil (65.44%) (P<0.05). The ratio of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) in the oils of front of the heart, front of the chest and lower abdomen were 0.59, 0.61 and 0.65, respectively. The results of total sterol and cholesterol in the oil samples showed that the highest amount of total sterol (125.91 mg/100 g) and cholesterol (95.82 mg/100 g) were obtained in the oil of front of the heart. The highest levels of delta tocopherol (0.98 mg/100 g) were in the oil of anterior cardiac. The highest levels of alpha tocopherol (2.45 mg/100g) and beta tocopherol (0.87 mg/100g) were obtained in anterior thoracic oil. The samples were not different significantly in terms of gamma tocopherol and gamma tocotrienol. Melting point (29.31°C in all samples), refractive index (1.45 in all samples), yellow (35 Lovibond) and red (2 Lovibond) colors in the oils of the front of the heart, front of the chest and lower abdomen did not show significant differences. The highest induction period was obtained in the oil of front of the heart (11.58 hours) and the lowest stability was related to abdominal part (11.44 hours), Therefor no significant difference was observed between the induction period of the samples (P<0.05).

    Conclusion

    In this study, the results of the analysis of fatty acids in the studied oils showed that the composition of ostrich oil fatty acids in the lower abdomen, front of the heart and in front of the chest are the same and only their amounts were evaluated differently. According to the obtained results, ostrich oil can be considered as a valuable oil in the food industry due to its high content of essential fatty acids and tocopherol compounds, low cholesterol and good stability.

    Keywords: Oil, ostrich, Physical, chemical properties
  • Fakhreddin Salehi *, Mohammadamin Asadnahal Pages 59-71
    Introduction

    Fried food products are very popular due to their unique characteristics such as color, smell, taste and desirable texture. During the frying process, food is immersed in an oil bath at a temperature above the boiling point of water. This results in counter flow of water vapour (bubbles) and oil at the surface of the product. Colour changes measured may be used to predict both chemical and quality changes in a food. The colour parameters have previously proved valuable in describing visual colour deterioration and providing useful information for quality control in fruits and fruit products. The oil uptake problem associated with fried products can be decreased by using hydrocolloids as edible coating. Also, the sensorial examination results showed that the coated products with gums have total acceptability better than the uncoated samples. Using of hydrocolloids (gums) to decrease the oil uptake during deep-fat frying is one of the easy and most convenient way which does not needs changes in frying devises (Khazaei et al 2016; Salehi 2020a). The term “gum” is used to explain a group of naturally occurring polysaccharides. Gums have a good functional characteristic such as emulsifying, coating agents, packaging films, gelling, stabilizers, solubility and textural improvement (Salehi 2017). Gums influence on the gelatinization and retrogradation of starch and decreased the retrogradation of starch. Wild sage seed mucilage is a gum extracted from wild sage (Salvia macrosiphon L.) seeds. The performance of artificial neural networks (ANN) was reported by some researcher. They reported that these approaches are able to estimated characteristics of various fruits and vegetables with high precision. It has been shown that nonlinear approaches based on ANN are far better in generalization and estimation in comparison to empirical models. Determination of the best number of neurons in hidden layers of ANN models is generally carry out by trial and error. The genetic algorithm optimization method can be used to overcome this inherent limitation of ANN. Genetic algorithm is the search technique for optimal value, mimicking the mechanism of biological evolution. It has a high capability to find the optimum value of a complex objective function, without falling into local optima (Salehi 2020b; Amini et al 2021).

    Material and methods

    The cleaned wild sage seeds were firstly soaked in water at a seed/water a portion of 1:20, 25°C, and for 20 min. The mucilage extract was separated from the swollen wild sage seeds by passing the seeds through an extractor. Controlling frying conditions and using edible hydrocolloid coatings (gums) is one of the best ways in reduction of oil uptake, moisture retention and improving the appearance properties of fried foods. In this study, different concentrations of wild sage seed gum (0, 0.5, 1 and 1.5%) were used to coating of eggplant slices during deep frying at 150, 175 and 200°C and the relationship between process parameters and the quality of final product were modeled by genetic algorithm-artificial neural network method. To examine the changes in colour indexes including lightness (L*), redness (a*) and yellowness (b*), images were taken after the frying. In order to investigate the effect of frying temperature and wild sage seed gum concentration on the colour changes of fried eggplant, a computer vision system was used. Sample illumination was achieved with HP Scanner (Hp Scanjet 300). Neurosolution software (version 5, NeuroDimension, Inc., USA) was employed for making the GA-ANN model. In the hidden layers and output layer a sigmoid activation function was used (due to the highest r-values in comparison to the other functions, hyperbolic tangent and a linear).The Levenberg–Marquardt (LM) optimization method was applied to network training. The crossover probability and the mutation probability operators were adjusted equal to 0.9 and 0.01, respectively. Also, a sensitivity analysis was done to supply the measure of relative significance between the inputs of the ANN model and to show how the model output changed in response to input changes.

    Results and discussion

    The results of this study showed that coating with wild sage seed gum reduced the oil uptake of the final product. Coating pretreatment maintained the final product moisture and moisture content of the sample coated with 1.5% wild sage seed gum was higher than the other samples. This process was modeled by genetic algorithm-artificial neural network method with 2 inputs include wild sage seed gum concentration and frying temperature and 5 outputs includes oil percentage, moisture content, and three main color indexes (yellowness (b*), redness (a*), and lightness (L*)). The results of modeling showed that a network with 3 neurons in a hidden layer and using the sigmoid activation function can predict the physicochemical properties of fried eggplant slices.

    Conclusion

    Wild sage seed gum concentration and oil temperature are the process parameters which affect the parameters of eggplant slices during frying. Sensitivity analysis results showed that the changes in the concentration of wild sage seed gum had the highest effect on the moisture content and then on the oil content of fried eggplant slices. Also, the change of frying temperature has the highest effect on the lightness index of fried samples.

    Keywords: Coating, Eggplant slices, Frying, Sigmoid activation function, Wild sage seed gum
  • Maryam Ataee, Maryam Khakbaz Heshmati *, Jalal Dehghannya, Saeed Dadashi Pages 73-87
    Introduction

    The broccoli is a vegetable that belongs to family of Cruciferae and genus Brassica. It is a rich source of minerals such as potassium, phosphorus, calcium and sodium. Additionally, broccoli provides vitamins, especially vitamin C, vitamin A and folic acid. Also it has been reported as the one of main sources of natural antioxidants such as phenolic compounds, glucosinolates and isothiocyanates. Because of the high corruptibility of broccoli, it is very important to prevent broccoli from corruption to keep its effective components as much as possible. Drying is the most common method for enhance shelf life of food products. The foam mat drying method was developed in the 1960s. This method involves mixing pulp or fruit and vegetable juices with a foaming agent and a foam stabilizer to prepare a stable foam that is spread and dried on a tray, then the dried product is ground to a powdered product. In this technique, due to increasing of the material area, the drying rate is high. Convective hot air is generally chosen as the drying medium of the foam mat method. The disadvantage of this drying method is the poor heat transfer of the air around the foam. Microwave heating, with its ability to produce volumetric heat inside the material, can overcome this limitation. Microwave energy can penetrate directly into the foamed pulp to evaporate moisture inside the foam; continuously generated vapors stimulate foam bubbles, which expand the evaporation level and speed up the drying process even more. There are many strategies to improve the quality of microwave-dried products, such as combining microwave and convective hot air, intermittent drying, and microwave -vacuum drying. The combination of microwave and convective hot air has been used successfully for a number of agricultural products such as garlic, grapes, carrots, kiwis and blueberries. The combination of these two methods has a shorter drying time than single convective hot air, and the final sample will have higher quality.

    Material and methods

    Broccoli was purchased from the local market of Tabriz and its enzymes were inactivated by blanching. It was then pulped and stored in a freezer at minus 18°C. 3% (w/w) egg white as foaming agent and 0.5% (w/w) methyl cellulose as stabilizer agent were used to prepare the foam. Foam, with a thickness of 5 mm, was dried with different drying methods including convective hot air (at 40°C and air velocity of 1m/s), microwave (90w) and combination of microwave and convection as pre and post treatment (MW-CHA and CHA-MW) until it reached a constant weight. The moisture content of samples was measured at 10-min intervals (in CHA method) and at 2-min intervals (in MW method), and the drying process was terminated when moisture content of the samples reached 0.04 g water/g dry solids. The produced powders were then scratched off by a special spatula and were immediately ground in a crucible in order to prevent further moisture absorption.

    Results and discussion

    The combination of microwave and convective hot air (in both pre and post treatment) compared to microwave method, had lower effective moisture diffusivity coefficient and drying rate but higher energy consumption. The average of moisture content and moisture ratio was also affected by drying method and the combination of microwave and convective hot air (MW-CHA and CHA-MW). In MW-CHA, the average of moisture content and moisture ratio was higher than MW and CHA drying method, but in CHA-MW, the average of moisture content and the moisture ratio was the lowest obtained.

    Conclusion

    According to the least energy consumption, drying time, moisture content and the moisture ratio and most effective moisture diffusivity coefficient and drying rate, MW and CHA-MW were the optimum methods for drying the broccoli foam (with 0.88 and 0.7 desirability, respectively).

    Results and discussion

    The combination of microwave and convective hot air (in both pre and post treatment) compared to microwave method, had lower effective moisture diffusivity coefficient and drying rate but higher energy consumption. The average of moisture content and moisture ratio was also affected by drying method and the combination of microwave and convective hot air (MW-CHA and CHA-MW). In MW-CHA, the average of moisture content and moisture ratio was higher than MW and CHA drying method, but in CHA-MW, the average of moisture content and the moisture ratio was the lowest obtained.

    Conclusion

    According to the least energy consumption, drying time, moisture content and the moisture ratio and most effective moisture diffusivity coefficient and drying rate, MW and CHA-MW were the optimum methods for drying the broccoli foam (with 0.88 and 0.7 desirability, respectively).

    Keywords: Broccoli, convection, Foam mat, Hot air, microwave
  • Farid Bejaei, Sadegh Seyyedlou, Habibeh Nalbandi *, Hamid Reza Ghassemzadeh Pages 89-107
    Introduction

    Bread is one of the most important food sources for consumers, especially in developing and underdeveloped countries. Large quantities of bread are wasted every year because different factors affect the number of waste products include flour quality, bread production technology, and the storage condition of the bread. Among the factors affecting the quality of the flatbread, technological factors including the source and method of heating the dough and the type of baking bed are very important. Those factors affect the quality and staleness of the bread and the amount of energy consumed per ton of the produced flatbread. All of these issues depend on how heat and mass are transferred. At present, for the baking of the flatbread, direct heat transfer of the burner (torch) to the dough is utilized in the Iranian bread industry. The use of the direct heat method in baking causes non-uniform heat distribution and non-uniform baking of the flatbread. Also, it causes the deposition of some chemical compounds such as benzopyrenes on the surface of the bread due to incomplete combustion of fuel and gases from the burning process of fossil fuels. At present, the change in the structure of bread production from traditional methods to industrial methods is one of the most important factors in the production of safe and standard bread while improving its quality. The objective of this study was to improve existing systems and developed the new flatbread industrial baking machine to increase product quality and product storability.

    Materials and methods

    The design and construction of the oven were performed based on the existing machine in the bread industry. The final dimension of the bread baking machine was 250 ×250 cm, a height of 160 cm. Rotary bread baking machine with an indirect heating system was designed and heat exchangers of the machine were simulated. The uniformity of airflow velocity inside the exchangers and the distribution of heat on the dough on the baking bed were investigated. After achieving the most effective design, the exchangers were constructed and installed inside the baking machine. A rotary baking bed was constrained with cast iron with a diameter of 220 cm and a thickness of 18 mm that was able to rotate horizontally. A three-phase electric motor with a speed of 1400 rpm and a power of 1.5 kW was used for the rotation system of the bed and carousel assembly. Two heat exchangers with an optimized shape were constructed with SS310 coupled with 2 burners. Bread baking experiments with the developed machine and the existing conventional machines were conducted to evaluate the sensory and staling characteristics of the produced flatbreads from different baking machines.

    Results and discussion

    The simulation results indicated that the air velocity in the center of the middle pipes of the upper exchanger with a standard deviation of 0.05 was in the range of 1.552 to 1.72 ms-1, which means an acceptable uniformity. In the lower heat, there was a relatively uniform air distribution. The experimental validation of the developed simulator indicated that there is good agreement between the measured and predicted air velocity. In the top exchanger, R2 and RMSE were 0.9 and 0.36, respectively and in the top exchanger, they were calculated to be 0.97 and 0.218, respectively. The results indicated that the sensory qualities of the bread produced with the indirect heating system in the present study as well as uniformity of baking and sensory acceptability were superior compared to the bread produced from the conventional industrial machines with direct heating systems (with a total sensory score of 5.09 vs. 4.54). Mold was also observed in a few breads, with direct heating samples, after 168 hours of storage. However, no significant changes were observed in the quality of the bread cooked by direct heating methods after 48 hours of storage, and this type of flatbread lasted more than 168 hours without mold. It should be noted that mold is one of the most important quality deterioration factors and its weight in the quality assessment of the bread is greater than the other quality evaluation factors even though it has not been included directly in the evaluation standards. If the bread becomes moldy, it will be unsafe for consumption and fully wasted. Accordingly, the flatbread produced by the indirect heat was the best choice for long-term storage purposes and the reduction of food waste. Another feature that was evaluated in the bread was the uniformity of baking of all parts of the flatbreads. One of the main problems with the industrial direct heat baking machines is the fact that the outer edges of the flatbread burn due to the inadequacy and somehow incompatibility of the exchangers with the baking space, the dimensions of the flatbread, and incorrect design of the heat exchangers. The flatbread baked with indirect heat and the newly designed exchangers was very uniform with no signs of burning in the outer edges of the bread.

    Conclusion

    In general, the results of the current study indicated that the use of the simulation tools, the design and manufacturing of the new exchangers and uniform indirect heating of the baking bed resulted in the production of higher quality bread which could be stored for a longer period of time while reducing the food waste. Also, bread prepared using the new machine was free of any contaminants such as PAHs.

    Keywords: Conservation laws of momentum, Flatbread, Heating system, Industrial backing, Sensory evaluation, Simulation
  • Shahin Zomorodi *, Elham Azarpazhooh, Parvin Sharayei Pages 109-121
    Introduction

    Orange peel essential oil is used in various industries as a flavoring component due to its excellent organoleptic properties. These compounds are generally rich in active and sensitive components (antioxidant and antimicrobial compounds). These compounds typically have low physicochemical stability and lower solubility in water. Therefore, the use of a method that can protect these compounds against environmental factors is of particular importance. Microencapsulation is one of the methods of protecting chemical compounds with biological activity. Since the microencapsulation process of the active compounds is influenced by the core and wall material and drying method, it is expected to use suitable wall materials such as sodium alginate and beta-cyclodextrin with a suitable drying method such as freeze drying lead to the production of stable microcapsules. The aim of this study was to produce microencapsulation of orange peel essential oil extracted from Thomson cultivar with walls of sodium caseinate and beta cyclodextrin by freeze-drying method and to investigate its quantitative and qualitative characteristics.

    Materials and Methods

    Orange peel was subjected to ultrasound at a frequency of 20 kHz with 60% intensity for 19 minutes at 35 °C and then its essential oil was extracted by Clevenger method. The extracted essential oil was finely Microencapsulate using beta-cyclodextrin and sodium caseinate at concentrations of 5 and 10% by freeze-drying method at -70 ° C for 19 hours and then transferred to a freeze-dried dryer. Samples were dried in a freeze-dryer at -55 ° C with a pressure of 0.15 mm Hg (Azarpazhooh et al. 2018). Then the properties of capsulate essential oil including Microencapsulate efficiency, particle diameter size were used using laser light refraction method. moisture was measured using an infrared hygrometer at 105 ° C until reaching a constant weight. To determine the mass density, a specific volume of the sample, its weight and density were calculated by dividing the weight (g) by the volume of the sample (ml) in g/ cm3. The glass transition temperature was determined using a differential scanning calorimeter with a liquid nitrogen cooling system. To determine phenolic compounds, Folin–Ciocalteu method was used. The antioxidant activity of the samples was also measured using the DPPH test. Scanning electron microscopy was used to observe the microstructure of the prepared microcapsules. Stability kinetics of microcapsules were performed under different temperature and humidity conditions (temperature, 4 and 25 °C; relative humidity, 52 and 75% and storage time of 0, 7, 14, 21, 28, 35 and 42 days) in three replications. The results were analyzed using a completely randomized statistical design with 3 replications and MSTATC software.

    Results and discusses

    The results of statistical analysis of data showed that the effect of wall material on all properties of microcapsules was significant (p <0.05). Thus, all the characteristics of microcapsules prepared with beta-cyclodextrin wall except mass density were significantly higher than the characteristics of microcapsules prepared with sodium casinate wall. The low production efficiency of microcapsules containing sodium caseinate is probably due to the instability of the initial emulsion. Also, the lower moisture of these microcapsules is another reason for the low efficiency. Microcapsules with 10% beta-cyclodextrin and 5% sodium caseinate had the highest and lowest moisture and efficiency, respectively. Therefore, the type and concentration of wall material effectively affects the efficiency and final moisture of the microcapsules. The bulk density of microcapsules with beta-cyclodextrin wall was lower than that of sodium caseinate. Because of their greater porosity, beta-cyclodextrin-containing microcapsules will take up more volume than sodium caseinate microcapsules. As a result, their bulk density is lower. The small particle size of microcapsules containing sodium caseinate is related to the effective emulsifying properties of sodium caseinate and its hydrophobic and hydrophilic components (Moghimi et al. 2016). The large particle size of beta-cyclodextrin-containing microcapsules may be due to the lack of ionization of beta-cyclodextrin, which tends to accumulate in water, there is no repulsive force to prevent particle aggregation (Torres-Alvarez et al. 2020). Moisture and efficiency of microcapsules increased with increasing concentration of beta-cyclodextrin but decreased with increasing concentration of sodium caseinate. Also, with increasing the concentration of both walls, the density of the mass increased and the glass transition temperature and free radical scavenging decreased (p <0.05). Also, the glass transfer temperature of all microcapsules is higher than the ambient temperature. Therefore, none of the microcapsules prepared at ambient temperature reach the glass transition temperature, so it is not possible to release and transfer the core material out of the wall. As the concentration of both walls increased, the glass transition temperature decreased (p <0.05). The results of determining the microstructure of the microcapsuleed particles by electron microscopy showed that the resulting microcapsules did not have a definite geometric shape, which is probably due to the drying mechanism. Spherical capsules containing beta-cyclodextrin had a large indentation and pore, and microcapsules containing sodium caseinate had thin, uniform, non-porous walls. The results of the study of the stability of microcapsules indicate that during storage the amount of DPPH increased with increasing relative humidity but decreased with increasing temperature from 4 to 25 °C.

    Conclusion

    Orange peel essential oil capsules prepared with 10% beta-cyclodextrin wall had better physicochemical properties than other walls.

    Keywords: Essential Oil, Microencapsulate, Orange peel, Process by-product
  • Nooshin Noshirvani *, Hadi Fasihi Pages 123-138
    Introduction

    Preparation of edible coatings is considered as one of the effective ways to increase the shelf life of fresh fruits (Hashemi et al 2017). Edible films or coatings contain a continuous matrix of protein, polysaccharide or lipid (Cagri et al 2004). The use of edible coatings has an effect on the product by changing the atmosphere inside the package, reducing the microbial load and delaying weight loss and respiratory reactions, as well as protection against physical damages. CMC, as a cellulose-derived compound, is a biopolymer that has the ability to form gel and shows outstanding film-forming properties. Also other properties such as water solubility, transparency, odorless, tasteless, high viscosity, non-toxicity and flexibility with medium strength and permeability to moisture and gases make it a suitable option for coating preparation (Fasihi et al 2017). Active packaging involves the addition of specific compounds to the film or packaging coating or inside packaging containers in order to increase the shelf life of the product. The most important benefit of adding active compounds to films and packaging coatings is the slow release of antimicrobial compounds from the packaging material, which results in high concentrations of the active compound at the product surface for a long time. This method is more effective than adding antimicrobial agent directly by spraying its solution on the surface of the product (Noshirvani et al 2017a). Spices and herbs are widely used in the food industry as flavorings. Recently, a large number of spices or essential oils have been identified as antimicrobial and antioxidant compounds. Many natural compounds, such as essential oils and their constituents, are recognized by the US Food and Drug Administration (GRAS) as healthy ingredients. Ginger and savory have outstanding antimicrobial and antioxidant properties and many studies have been done on these properties. The use of savory and ginger essential oils as strong antimicrobial compounds in the structure of active coatings can improve the quality properties of fresh cucumber.

    Objective

    The aim of this study was to prepare active coatings based on CMC containing ginger and savory essential oils in two concentrations of 250 and 1000 ppm in order to preserve fresh cucumber.

    Material and Methods

    CMC based active coatings containing two levels (250 and 1000 ppm) of ginger and savory essential oils were prepared. In order to prepare coatings, CMC with two concentrations of 1 and 1.5% (w / v) was dissolved in distilled water and Tween 80 was added as emulsifier (25% w/w essential oil). Then different concentrations of savory and ginger essential oils (250 and 1000 ppm) were added after passing through the filtered syringe. Cucumbers were immersed in the solution for 3 minutes and then dried for 12 hours at 25°C. The samples were placed in polyethylene bags and stored at 10°C. To prepare the control sample, fresh cucumbers were placed in distilled water for one minute. The effect of coating on some properties of fresh cucumber such as weight loss, pH, acidity, total soluble solids, color, microbial count and sensory properties of coated cucumbers were examined during a 16-day storage period at 10°C. Fresh uncoated cucumbers were considered as control sample.

    Results and Discussion

    Based on the results, the use of active coatings containing ginger and savory essential oils significantly reduced weight loss and microbial growth in cucumber. The content of weight loss for the control sample was 13.6% after 16 days, while the samples containing the coating showed less weight loss. Weight loss is one of the most important changes after fruit harvest due to the migration of moisture from the surface of the fruit to the environment and its extent depends on the difference in water vapor pressure between the fruit tissue and the surrounding atmosphere (Sarker and Partners 2021). In addition, fruit respiration may lead to weight loss. Applying the coating on the fruit surface acts as a barrier against the passage of moisture from the fruit to the environment and reduces weight loss. Also, the reduction in fruit weight loss is probably related to the effects of the coating as a semi-permeable barrier against oxygen, carbon dioxide, moisture and solids, and thus will be associated with reduced respiration rate, weight loss and rate of oxidation reactions. The results indicated that in the treatments that used savory essential oil, the microbial spoilage of the fruit was reduced and the firmness of the fruit tissue was maintained. The treatment containing CMC coating was better controlled weight loss due to fruit moisture retention and increased the firmness of cucumber compared to the control sample at each stage of storage time. According to the results, the yellow color in all samples increased over time, which indicates a decrease in the green color of cucumber peel. However, the coated samples showed less yellow color than the control sample. Therefore, the presence of coating seems to reduce chlorophyll degradation by delaying fruit ripening and aging. The amount of total soluble solids, pH and acidity in the control sample changed more than the samples containing the coating due to the high rate of metabolic activities. The results of sensory evaluation indicated the lowest scores for control among the different samples, so that all scores obtained for this sample were below 3.5, which indicates that this sample is unacceptable in terms of the factors under study. The reason for the low score for the control sample is related to color changes (yellowing and browning), shrinkage due to high moisture loss and mold contamination. After the control sample, the samples coated with pure CMC in both concentrations used scored lower because of the microbial growth in these two samples after the storage period. Comparison of samples containing pure CMC coating and containing savory and ginger essential oils showed a higher score for samples containing essential oil. The presence of ginger and savory essential oils in the coating due to the antimicrobial effects of the essential oils used in the coating formulation prevents the activity of microorganisms, which leads to maintaining the quality of cucumber during storage. Comparison of samples with savory and ginger essential oils showed a higher score for savory compared to ginger essential oil, which is related to the stronger antimicrobial effects of savory essential oil than ginger.

    Conclusion

    Among the different coatings used in this study, the coating of CMC containing savory essential oil at both 250 and 1000 ppm concentrations showed a higher effectiveness in maintaining the quality of fresh cucumber. Due to the fact that CMC is a water-soluble biopolymer, so it is easily washed before consumption and no trace of coating will remain on the surface of the fruit. Based on the results, the use of CMC coating containing savory essential oil at both 250 and 1000 ppm concentrations indicated lower weight loss, desirable stiffness, better preservation of color, good microbial quality and sensory properties which is associated to strong antimicrobial properties of savory essential oil along with the presence of CMC coating.

    Keywords: Cucumber, Antimicrobial coating, Carboxymethyl cellulose, Savory essential oil, Ginger essential oil
  • Mohammad Aboonajmi *, Maryam Ganjdoost, Hossein Mirsaeedghazi, Keyvan Asefpour Vakilian Pages 139-152
    Introduction

    White edible button mushroom (Agaricus bisporus) is one of the most sensitive postharvest agricultural products physiologically. Poor management and high humidity of freshly harvested horticultural products have reduced their shelf life and thus increased biowastes, so increasing the shelf life of fruits and vegetables to reduce waste is one of the essential goals of postharvest management. The shelf life of button mushrooms with minimal processing is between two and four days at average ambient temperature due to enzymatic browning. A method in increasing the storage of edible mushrooms is using power ultrasonic washing along with other treatments. Ultrasonics is one of the practical methods of non-contact washing of vegetables and fruits with sensitive textures. Ultrasound pretreatment involves immersing the fruit in distilled water or aqueous solution and applying the ultrasound simultaneously. Ultrasound causes a series of rapid contractions and intermittent expansions. The objective of this study was to investigate the effects of using power ultrasound alone and in combination with other treatments such as hydrogen peroxide and ozone on improving the postharvest characteristics of ediblemushrooms.

    Materials and methods

    In this study, the button fungus (Agaricus bisporus) was used. The fungi were relatively the same size without physical damage and fungal infections. In order to create ultrasonic waves, a Unident Geneve ultrasonic bath machine made in Switzerland with a production power of 100 watts and a frequency of 20 to 35 kHz was used to wash the desired product. The application time of ultrasound for this study was 4 and 6 minutes and it was used at a constant temperature of 20 degrees Celsius. Also, in this research, the ARDA Ozone Plus series ozone generator was used to produce ozone. The amount of ozone produced by this device without oxygen capsule (mgr) is 200 ⁄h. In the present study, the effect of different treatments on increasing the storage of edible mushrooms, physical and chemical properties such as weight loss, pH, stiffness, soluble solids and microbial load were tested.

    Results and discussion

    Weight loss percentage is one of the most important factors in quality assessment in fruits and vegetables, which is directly related to the amount of moisture content in the samples. During the storage period, the lower the moisture release rate, the smaller this factor becomes, which indicates the retention of moisture in the sample and its quality stability. Comparison of samples During the storage period, there is an increasing trend in weight loss of samples that the amount of weight loss in the control sample is significantly higher than the samples washed by ultrasound. As the amount of maturation due to cell disintegration due to enzymatic activity increases, the firmness of the fruit tissue will also decrease. Tissue loss is the most important change during the storage period of fruits and vegetables and depends on the rate of metabolic changes and water. The reason for the increase in stiffness again is that the fruit and vegetable samples usually start to lose their water gradually. Obviously, this leads to an increase in their stiffness index. Changes in the texture of the fungal cap are an important criterion for determining the quality, amount of metabolic changes and the amount of water in its texture. Decreased strength and softening in the fungal cap tissue is related to the activity of microorganisms and enzyme production. Bacteria with enzymatic activity on the mushroom cause the interstitial material in the mushroom cap to break down and lead to cell destruction, resulting in the loss of tissue and shrinkage. At the end of the twelfth day of storage, the lowest stiffness is related to the ultrasonic treatment of 4 minutes and the highest stiffness is related to the treatment with washing with distilled water for 4 minutes, which shows the highest amount of wood and drying of the fungus. The reason for the decrease in stiffness during the storage period may be due to the breakdown of enzymes, water depletion or degradation of pectic substances in the fruit. The soluble solids from the fungus to distilled water are subjected to ultrasound. The results show that the treatments washed with sonication and hydrogen peroxide have a high performance in terms of microbial load control compared to the control mode and other treatments and have a significant difference at the level of 0.01. Ultrasonic treatment with hydrogen peroxide for 6 minutes of ripple on the first day of storage had 61 and at the end of the storage period had 87.5 cfu / g microbial load.

    Coclusion

    Ultrasonic washing of agricultural products is one of the ways to increase the shelf life of agricultural and horticultural products. The results of this study show that the samples of mushroom washed with sonication and hydrogen peroxide have a high performance in terms of microbial population control compared to the control mode and other treatments and have a significant difference. Ultrasonic treatment with hydrogen peroxide for 6 minutes on the first day of storage had 61 and at the end of storage period 87.5 cfu / g microbial load. Samples with ozone and ozone-containing treatments combined with sonication with ultrasound have a higher ability to maintain the strength of mushroom tissue. According to the studied treatments and traits, the obtained results show that the sonication treatment with ultrasound with hydrogen peroxide for 6 minutes has the best performance to increase the shelf life of the edible mushroom.

    Keywords: edible mushrooms, Hydrogen peroxide, power ultrasound, storage