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پژوهشهای علوم و صنایع غذایی ایران - سال دوازدهم شماره 2 (پیاپی 38، خرداد و تیر 1395)

نشریه پژوهش های علوم و صنایع غذایی ایران
سال دوازدهم شماره 2 (پیاپی 38، خرداد و تیر 1395)

  • تاریخ انتشار: 1395/04/25
  • تعداد عناوین: 12
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  • مقاله پژوهشی فارسی
  • بهروز علیزاده بهبهانی، علی الغونه، فریده طباطبایی یزدی، فخری شهیدی، محبت محبی صفحات 201-213
    در این پژوهش اثر حلال های آب، اتانول، متانول و گلیسیرین هر کدام در پنج سطح (صفر، 25/31، 33/83، 125 و250 میلی لیتر) با استفاده از هندسه مخلوط برای استخراج عصاره برگ گیاه حرا استفاده شد. از مدل چند جمله ای شف و بهینه سازی عددی به منظور مدل سازی و بهینه سازی عصاره استفاده گردید. مدل چند جمله ای شف به طور معنی داری قادر به پیش بینی بازده حاصل از استخراج عصاره برگ حرا می باشد (میزان ضریب تبین و ضریب تبین اصلاح شده به ترتیب 94/0 و84/0 وغیر معنی دار بودن آزمون ضعف برازش و مقدار اندیس F ( 62/14) نشان دهنده صحت مدل برای پیش بینی بازدهی عصاره می باشد). به علاوه میزان ضریب تغییرات 6/14% محاسبه شد که نشان دهنده تکرار پذیری قابل قبول برای داده های آزمایشی است. میزان تابع مطلوبیت بهینه سازی 94/0 محاسبه شد که نشانگر صحت عملیات بهینه سازی می باشد. بر این اساس، فرمولاسیون بهینه حاوی گلیسیرین (صفر میلی لیتر)، آب (22/28 میلی لیتر)، متانول ( 83/59 میلی لیتر) و اتانول (95/161 میلی لیتر) بود. اثر ضد میکروبی عصاره های برگ گیاه حرا بر سه باکتری 33090 Listeria innocua ATTC، Enterococcus faecium ATTC 51559 وEscherichia coli ATTC 25992 به سه روش (انتشار در آگار به کمک دیسک، حداقل غلظت ممانعت کننده رشد و حداقل غلظت کشندگی) در هشت غلظت مختلف بررسی شد. نتایج نشان داد بیشترین اثر بازدارندگی بر Listeria innocua و بالاترین میزان مقاومت در برابر عصاره، مربوط به Escherichia coli بود، همچنین با افزایش غلظت عصاره ها قطر هاله باز دارندگی به طور معنی داری (05/0p
    کلیدواژگان: گیاه حرا، بهینه سازی، هندسه مخلوط، قطر هاله عدم رشد
  • محمد مهدی حیدری فروشانی، سید مهدی نصیری صفحات 214-225
    در این تحقیق روند تغییرات ویژگی های بافتی گلابی در تیمارهای مختلف خشک شدن به صورت لایه نازک در یک خشک کن قفسه ای در تیمارهای مختلف دما و سرعت هوای خشک کن مورد بررسی و مقایسه قرار گرفتند. آزمایش های خشک کردن در سه سطح دما (40، 50 و 60 درجه سانتی گراد) و سه سطح سرعت هوا (5/0، 1 و 5/1 متر بر ثانیه) انجام گرفت و ویژگی های بافتی نمونه های گلابی در پنج سطح محتوای رطوبتی (82، 66، 51، 35 و 20 درصد بر اساس وزن مرطوب) در شرایط مختلف خشک کردن اندازه گیری شد. در این پژوهش از یک سیستم داده برداری بر- خط برای جمع آوری اطلاعات استفاده شد. نتایج حاکی از آن بود که ویژگی های بافتی نمونه ها در طول فرایند خشک کردن تغییر کرده و این تغییرات مرتبط با شرایط خشک کردن است. با کاهش رطوبت محصول طی فرایند خشک شدن سختی بصورت نمایی و پیوستگی بصورت خطی کاهش و قابلیت ارتجاعی و چسبندگی به صورت خطی افزایش یافت. قابلیت جویدن در دامنه رطوبت اندازه گیری شده روند سهمی شکل از خود نشان داد به نحوی که بیشترین مقدار آن در محدوده رطوبت 40 تا 50 درصد مشاهده شد. تجزیه واریانس نشان داد تاثیر دما بر ویژگی های سختی، قابلیت ارتجاعی و قابلیت جویدن معنی دار (01/0> p) بود در حالی که بر پیوستگی و چسبندگی معنی دار نبود. افزون بر آن، مشخص شد که اثر سرعت هوا بر تمام این ویژگی ها معنی دار است. از آنجا که بر اساس نتایج به دست آمده کمترین مقدار قابلیت جویدن (46/0 ژول) مربوط به دمای 40 درجه سانتی گراد و سرعت 1 متر بر ثانیه بوده این تیمار بعنوان مطلوب ترین تیمار خشک کردن گلابی پیشنهاد می گردد. مدت زمان خشک شدن در این تیمار در حدود 5/33 ساعت بود که از کمترین زمان خشک شدن در شرایط 60 درجه سانتی گراد و 5/1 متر بر ثانیه تقریبا 24 ساعت طولانی تر و از بلندترین آن در شرایط خشک شدن 40 درجه سانتی گراد و 5/0 متر بر ثانیه در حدود 5/6 ساعت کوتاه تر بود.
    کلیدواژگان: گلابی، خشک شدن، خواص بافتی، خشک کن قفسه ای
  • اعظم ایوبی، ناصر صداقت، مهدی کاشانی نژاد، محبت محبی، مهدی نصیری محلاتی صفحات 226-238
    این پژوهش با هدف بررسی تاثیر شرایط خشک کردن (دمای خشک کردن در سه سطح (60، 70 و 80 درجه سانتیگراد)، سرعت جریان هوا در دو سطح (5/1 و 5/2 متر بر ثانیه) و پیش تیمار آماده سازی در چهار سطح (کربنات پتاسیم و روغن سبزه، روغن زیتون، آب داغ و بدون پیش تیمار آماده سازی)) بر شدت خشک شدن انگور و ویژگی های کیفی کشمش شامل بازجذب آب، چروکیدگی، سفتی بافت و شاخص قهوه ای شدن انجام شد. نتایج نشان داد که پارامترهای دما، سرعت هوا و پیش تیمار آماده سازی اثرات معنی داری بر شدت خشک شدن انگور و کیفیت کشمش دارند. افزایش دما و سرعت هوای خشک کردن و نیز استفاده از پیش تیمار آماده سازی موجب افزایش شدت خشک شدن انگور شد. مطلوب ترین مقادیر سفتی (73/0 نیوتن)، چروکیدگی (04/81 درصد) و کمترین شاخص قهوه ای شدن (157/0) مربوط به کشمش خشک شده در دمای 60 درجه سانتیگراد و بیشترین بازجذب آب (266/1) مربوط به کشمش خشک شده در دمای 70 درجه سانتیگراد بود. تاثیر سرعت جریان هوا، تنها بر شاخص قهوه ای شدن معنی دار شد. افزایش سرعت جریان هوا، کاهش شاخص قهوه ای شدن را به دنبال داشت. در بین پیش تیمارهای به کار رفته نیز، پیش تیمار کربنات پتاسیم و روغن سبزه نتایج فیزیکوشیمیایی بهتری را سبب شد.
    کلیدواژگان: کشمش، خشک کردن، سرعت هوا، شدت خشک شدن، شاخص قهوه ای شدن
  • سمانه پژوهان مهر، رضا فرهوش، رضا اسماعیل زاده کناری، علی شریف صفحات 239-249
    در این تحقیق، پایداری اکسایشی روغن تخلیص شده ماهی کیلکا (Clupeonella cultiventris caspia) در حضور روغن های مغز و پوست بنه (2-1 درصد وزنی/ وزنی) و اجزاء صابونی ناشونده آنها (5/1-1 درصد وزنی/ وزنی) بررسی و با اثر آنتی اکسیدان های سنتزی رایج نظیر آلفاتوکوفرول و بوتیل هیدروکسی تولوئن (BHT) (100 پی پی ام) با استفاده از روش رنسیمت در دمای 60 درجه سانتی گراد مقایسه شد. تغییرات شاخص پایداری اکسایشی نمونه ها در دمای 60 درجه سانتی گراد (60OSI، ساعت) بعنوان معیار سنجش پایداری اکسایشی در نظر گرفته شد. نتایج بر اساس داده های شاخص پلی ان و میزان ترکیبات صابونی ناشونده، توکوفرولی، فنلی و استرولی مورد تجزیه و تحلیل قرار گرفت. اجزاء تشکیل دهنده ترکیبات صابونی ناشونده روغن های مغز و پوست شناسایی و تعیین مقدار شدند. بیشترین میزان اجزاء تشکیل دهنده مواد صابونی ناشونده مغز و پوست بنه به ترکیبات توکوفرولی و توکوتری انولی تعلق داشت. 60OSI نمونه های شاهد (66/1 ساعت) در حضور کلیه ترکیبات آنتی-اکسیدانی افزایش یافت. به طور کلی ترکیبات صابونی ناشونده مغز بیشترین اثر آنتی اکسیدانی را از خود نشان داد، بطوری که 60OSI در حضور غلظت 5/1 درصد از این ترکیب تا 12/8 برابر افزایش یافت (60OSI برابر با 48/13 ساعت) (05/0p
    کلیدواژگان: پایداری اکسایشی، تری آسیل گلیسرول، روغن بنه، کیلکا، اجزاء صابونی ناشونده
  • محمد فرهادی چیتگر، مهدی وریدی، محمد جواد وریدی، احمد بالندری صفحات 250-260
    کسب اطلاعات در مورد گیاهان بومی بعنوان منابع غذایی عملگر (فراسودمند) رو به افزایش است. یکی از این گیاهان، گونه های وحشی زرشک(Berberis. spp.) می باشد که بررسی خصوصیات فیزیکی و شیمیایی آنها می تواند زمینه کاربردشان را در صنایع غذایی و دارویی فراهم کند. لذا در این پژوهش به منظور معرفی بیشتر این گیاه ارزشمند بومی، سه ژنوتیپ موجود در باغ کلکسیون زرشک پژوهشکده علوم و صنایع غذایی درسال 1390جمع آوری و برخی از خواص فیزیکی و شیمیایی آنها مورد بررسی قرار گرفت. نتایج حاکی از آن بود که بین خصوصیات فیزیکی بررسی شده فقط در طول میوه سه ژنوتیپ اختلاف آماری معنی داری در سطح 5 درصدوجود داشت. هر سه ژنوتیپ حاوی میزان بالای چربی، پروتئین، کربوهیدرات و خاکستر بودند. ژنوتیپ نوشین دارای بالاترین قند احیاکننده (222/0±03/8) و در نتیجه دارای مزه شیرین تری نسبت به دو ژنوتیپ دیگر بود. هر سه ژنوتیپ در مقایسه با سایر میوه ها رنگی نظیر شاتوتو زغال اخته حاوی مقادیر قابل توجهی آنتوسیانین (60/3927-17/950 میلی گرم/ لیتر) و ترکیبات فنلی (35/12-75/9 گرم/ لیتر) بودند که بیانگر خواص سلامت بخش این میوه های خودرو و بومی می باشد. بلحاظ مواد معدنی هر سه ژنوتیپ غنی از ریزمغذی های مورد نیاز بدن انسان نظیر پتاسیم، کلسیم، منیزیم و روی بودند.
    کلیدواژگان: آنتوسیانین، زرشک، خواص فیزیکوشیمیایی، فراسودمند
  • بابک قنبرزاده، اکرم پزشکی، حامد همیشه کار، محمد مقدم صفحات 261-275
    درون پوشانی ترکیبات آب گریز از جمله ویتامین های محلول در چربی در ساختارهای لیپوزومی، روشی بالقوه موثر جهت حفظ آنها در برابر واکنش های مخرب در طی دوره ی نگهداری، معرفی شده است. از جمله مزایای بالقوه ی لیپوزوم ها، امکان درون پوشانی هر سه دسته مواد محلول در آب، محلول در چربی و ترکیبات آمفی فیل و به کارگیری مواد طبیعی غذایی با اثرات مفید درمانی مانند لستین در تولید آنهاست. در این پژوهش، به تعیین ویژگی های نانولیپوزوم های حاوی ویتامین A پالمیتات تولید شده به روش هیدراسیون لایه ی نازک و به کمک امواج فراصوت و با استفاده از غلظت های متفاوت لسیتین-کلسترول (شامل60 -0، 50 -10، 40 -20و 30-30 میلی گرم) پرداخته شده است. به منظور تعیین خواص کاربردی نمونه ها، آزمون های تعیین اندازه و توزیع اندازهذرات، پتانسیل زتا، بررسی ریزساختار، کارایی درون پوشانی و پایداری نانولیپوزوم ها در طی مدت نگه-داری انجام گردیدند. اندازه ی ذرات در محدوده 76-115 نانومتر و توزیع اندازه ی ذرات باریک و تک مد (اسپن = 88/0 - 6/0) بود. افزودن کلسترول اثر معنی داری بر اندازه ی ذرات نشان نداد ولی مقادیر زیاد کلسترول موجب کاهش کارایی درون پوشانی گردید. با ورود کلسترول و هم چنین ویتامین به ساختار نانولیپوزوم، پتانسیل زتا از 29- به 58- میلی ولت افزایش یافت که نشان دهنده ی بهبود پایداری الکترواستاتیک نانولیپوزوم ها بود. در کل، غلظت 50 به 10 میلی گرم لستین به کلسترول، به عنوان غلظت مناسب در تولید فرمولاسیون بهینه نانولیپوزوم ها با توزیع ذره یکنواخت و تک مد (اسپن = 74/0) وکارایی درون پوشانی 8/15 % شناخته شد.
    کلیدواژگان: نانولیپوزوم، ویتامینA پالمیتات، درون پوشانی، پایداری، نانوحامل کلوئیدی
  • محبوبه کشیری صفحات 276-285
    بسته بندی ضدمیکروبی یک فناوری نوین نگهداری است که بر اساس رهایش عوامل فعال ترکیب شده با پلی مر بسته بندی، به درون محصول غذایی یا محیط اطراف بسته بندی برای افزایش کیفیت و امنیت غذایی طراحی شده است. با هدف استفاده از اسانس گیاهان بعنوان ترکیبات ضدمیکروبی طبیعی، فعالیت ضدباکتریایی اسانس آویشن شیرازی (.Zataria multiflora Boiss) درمحیط مایع (تماس مستقیم) و جامد ( فاز بخار) علیه Escherichia coli و listeria innocuaمورد مطالعه قرار گرفت. فیلم های زیست فعال زئین حاوی 5 و 10% وزنی اسانس آویشن شیرازی تولید و فعالیت ضدباکتریایی فیلم ها در محیط مایع و جامد آزمایشگاهی ارزیابی شدند. فعالیت ضدباکتریایی فیلم های زئین دارای 10% اسانس آویشن شیرازی برای بسته بندی سالاد الویه بعنوان یک مدل غذایی طی مدت 6 روز مورد ارزیابی قرار گرفتند. نتایج این پژوهش نشان داد که خواص ضد باکتریایی اسانس آویشن شیرازی در تماس مستقیم در مقایسه با فاز بخار از کارایی بهتری برخوردار بود. از لحاظ آماری اختلاف معنی داری در سطح آماری 5 درصد بین اندیس کاهش لگاریتمی فیلم زیست فعال زئین حاوی 5% اسانس آویشن در تماس مستقیم علیه Escherichia coli و listeria innocua وجود نداشت. هم چنین با افزایش غلظت اسانس در فیلم زیست فعال زئین اندیس کاهش لگاریتمی باکتریایی در محیط مایع افزایش یافت. علی رغم نتایج مطلوب ضدباکتریایی اسانس آویشن شیرازی در فیلم های زئین در تماس مستقیم، فیلم های زیست فعال زئین جهت کاهش آلودگی سالاد الویه بسته بندی شده از کارائی لازم برخوردار نبودند.
    کلیدواژگان: بسته بندی ضد میکروبی، زئین، اسانس آویشن شیرازی، سالاد الویه
  • مریم عزیزخانی، فهیمه توریان، مریم بریری صفحات 286-295
    با توجه به تاثیرات منفی نگهدارنده های شیمیایی بر سلامت مصرف کنندگان، توجه مراجع قانونی و صنایع غذایی بر کاربرد اسانس ها و عصاره های گیاهی بعنوان نگهدارنده های طبیعی در مواد غذایی متمرکز شده است. در این پژوهش تاثیر اسانس های ریحان و مریم گلی کبیر بر رشد لیستریا مونوسیتوژنز و آسپرژیلوس فلاووس طی دوره نگهداری پنیر سفید ایرانی مورد مطالعه قرار گرفت. روش های بکار رفته در این تحقیق مشتمل بر تعیین حداقل غلظت مهارکنندگی رشد (MIC)، حداقل غلظت باکتری کشی (MBC) و حداقل غلظت قارچ کشی (MFC) اسانس ها، تعیین تاثیر غلظت های مختلف اسانس ها بر رشد لیستریا و آسپرژیلوس در پنیر طی دوره نگهداری محصول بود. ترکیبات اصلی اسانس مریم گلی کبیر شامل لینالیل استات، لینالول و اسانس ریحان شامل لینالول و آلفا-کادینول بود.MIC و MBC اسانس مریم گلی، به ترتیب، معادل 015/0% و 02/0% و اسانس ریحان برابر با 05/0% و 06/0% برای لیستریا بود. همچنین، MIC و MFC در برابر آسپرژیلوس برای اسانس مریم گلی معادل 5/0% و 65/0% و برای اسانس ریحان برابر با 6/0% و 8/0% بدست آمد. غلظت 35/0% اسانس مریم گلی و 5/0% اسانس ریحان از تولید اسپور توسط قارچ در محیط کشت جلوگیری نمود. اسانس مریم گلی در غلظت 1% طی دوره نگهداری پنیر از رشد آسپرژیلوس بطور کامل بازداری نمود و جمعیت لیستریا را نسبت به شاهد log 6 کاهش داد. اسانس ریحان تاثیر ضدمیکربی ضعیف تری نسبت به اسانس مریم گلی کبیر نشان داد.
    کلیدواژگان: آسپرژیلوس فلاووس، پنیر، ریحان، لیستریا مونوسیتوژنز، مریم گلی کبیر
  • فریده شریفی، لطیفه پوراکبر صفحات 296-307
    گیاه زرشک (Barberry) متعلق به خانواده یBerberidaceae می باشد که بدلیل اثرات کاهش قند و فشار خون در طب سنتی استفاده می شود. هدف از این تحقیق بررسی مقایسه ای مقدار ترکیبات فنلی، فلاونوییدی، ظرفیت آنتی اکسیدانی، سنجش قدرت احیای آهن، سنجش MDA، توان پاک کنندگی رادیکال نیتریک اکساید درعصاره های الکلی وآبی زرشک) Berberis (integerrima×Vulgarisبود. بعد از جمع آوری میوه زرشک در آبان 1391 از منطقه قمچقای واقع در45 کیلومتری شهرستان بیجار استان کردستان تا زمان سنجش در فریزر نگهداری شد. سپس عصاره اتانولی، متانولی و آبی آن تهیه گردید. سنجش میزان فنل و فلاونوئید تام به روش اسپکتروفتومتری ، فعالیت آنتی اکسیدانی عصاره ها با استفاده از رادیکال آزاد DPPH و قدرت احیای آهن به روش FRAP اندازه گیری شد. نتایج بدست آمده نشان داد که عصاره آبی دارای بیشترین میزان فنل (49/0 ± 98/48 میلی گرم در گرم وزن تر)، بیشترین میزان فلاونوئید متعلق به عصاره متانولی (033/0±93/1، میلی گرم در گرم وزن تر)، بالاترین ظرفیت آنتی اکسیدانی در عصاره متانولی (99/0±62/44 درصد)، بیشترین قدرت سنجش احیا در عصاره متانولی (42/0±89/5 میلی مول در گرم وزن تر) ، بیشترین میزان مالون دی آلدئید در عصاره متانولی (79/0±12/37 میلی مول بر گرم وزن تر) و بالاترین قدرت پاک کنندگی رادیکال نیتریک اکساید در عصاره آبی (56/64±60/723 درصد) دیده شد. نتایج نشان داد که عصاره های آبی و الکلی زرشک می تواند به عنوان آنتی اکسیدان طبیعی عمل نموده و پس از آزمایش های تکمیلی در صنایع غذایی و دارویی به کار رود.
    کلیدواژگان: زرشک (DPPH، (Barberry، فلاونوئید، FRAP
  • افشین فریدی اسفنجانی، سید مهدی جعفری، الهام اسدپور، حبیب الله میرزایی صفحات 308-317
    هدف از این پژوهش بررسی سینتیک رهایش پیکروکروسین، کروسین و سافرانال نانوریزپوشانی شده در فاز آبی داخلی امولسیون دوگانه آب در روغن در آب (W/O/W) به فاز آبی بیرونی آن بود. ترکیبات موثره ی زعفران به روش غرقابی استخراج و وارد امولسیون دوگانه گردیدند. برای این منظور، ابتدا میکروامولسیون عصاره ی زعفران در روغن به روش میکروامولسیون تشکیل و سپس این سامانه در فاز آبی شامل پروتئین آب پنیر و مالتودکسترین به صورت تک لایه و پروتئین آب پنیر-پکتین و مالتودکسترین به صورت دولایه دوباره امولسیونه شد. به منظور بررسی سینتیک رهایش ترکیبات موثره ی زعفران به فاز آبی بیرونی امولسیون دوگانه، ابتدا مدل های تجربی درجه صفر، درجه اول، هیگوچی و هیکسون-کراول در نظر گرفته شدند. با بررسی داده های آزمایشگاهی مشاهده شد که امولسیون دوگانه پایدار شده با کنسانتره پروتئین آب پنیر و پکتین دارای بیش-ترین گرانروی و کم ترین درصد رهایش پیکروکروسین، کروسین و سافرانال در طی 22 روز نگهداری بود. در مورد رهایش کروسین، بهترین مدل مربوط به مدل مرتبه اول و در مورد رهایش پیکروکروسین و سافرانال بهترین مدل مربوط به مدل مرتبه صفر بود. مبنای مقایسه مدل های بررسی شده، ضریب برازش (R2) ، مربعات خطا (SSE) و ریشه میانگین مربعات خطا (RMSE) بود.
    کلیدواژگان: رهایش، نانوریزپوشانی، امولسیون دوگانه آب در روغن در آب، زعفران
  • نسیم پورابراهیم، مسعود یاورمنش صفحات 318-329
    هدف از این پژوهش، بررسی رابطه احتمالی بین حضور کپک آسپرژیلوس و ژن های مولد آفلاتوکسین با شمارش کپک و مخمر، شمارش کلی میکرارگانیسم های مزوفیل و درصد رطوبت در پسته خام بود. بدین منظور نمونه برداری از مناطق مختلف کشت پسته درشهرستان های گناباد و فیض آباد انجام شد. در این تحقیق، 30 جدایه قارچی متعلق به جنس آسپرژیلوس شناسایی و به کمک روش های مبتنی برکشت و با استفاده از محیط کشت پوتیتو دکستروز آگار خالص سازی شدند. شناسایی جنس آسپرژیلوس با استفاده از واکنش زنجیرهای پلیمراز توسط جفت آغازگر اختصاصی Asp1/Asp2 جهت تکثیر ناحیه 18S rRNA انجام گردید. همچنین ردیابی ژنهای دخیل در مسیر تولید آفلاتوکسین توسط 3 جفت آغازگر APA-450/APA-1482،ver1/ver2 و OMT-208/OMT-1232 صورت گرفت. از میان 30 جدایه قارچی، 12 نمونه حاوی ژن omtA و 4 نمونه حاوی ژن ver1 بودند. در هیچیک از جدایه های قارچی ژن تنظیمی aflR مشاهده نشد. نتایج بدست آمده نشان داد که هرچند بعضی از جدایه ها یک یا دو ژن ساختاری دخیل در مسیر بیوسنتز آفلاتوکسین را دارند ولی با توجه به عدم حضور ژن تنظیمی aflR، بصورت بالقوه قادر به تولید آفلاتوکسین نمیباشند. جهت بررسی رابطه احتمالی بین حضور کپک آسپرژیلوس و ژنهای مولد آفلاتوکسین در پسته، ضریب همبستگی محاسبه گردید. نتایج بررسی های آماری نشان داد که همبستگی بالایی بین حضور کپک آسپرژیلوس و ژنهای ver1 و omtA بر اساس دامنه رطوبت وجود دارد (05/0p
    کلیدواژگان: آسپرژیلوس، آفلاتوکسین، پسته، ژن های مولد آفلاتوکسین، واکنش زنجیره ای پلیمراز
  • سعید میرعرب رضی، محبت محبی، محمدحسین حداد خدا پرست، آرش کوچکی صفحات 330-339
    در این پژوهش اثر مقادیر مختلف ژلاتین (1، 2 و 3گرم) و سدیم کازئینات (1، 2 و 3 گرم) بر ویژگی های حسی و رئولوژیکی نمونه های موس شکلات بررسی شد. همچنین از روش تجزیه به مولفه های اصلی جهت تعیین روابط پارامترهای حسی و بدست آوردن مولفه های اصلی استفاده گردید. مشاهدات نشان داد نمونه موس شکلات حاوی دو گرم ژلاتین و سه گرم سدیم کازئینات بهترین ویژگی های حسی را داشت. نتایج حاصل از برازش داده نشان داد که مدل پاورلا با داشتن R2 بالا (99/0R2>) و RMSE پایین بهترین مدل جهت توصیف رفتار جریان می باشد. ضریب قوام در نمونه ای از موس شکلات که سه گرم ژلاتین و سه گرم سدیم کازئینات را دارا بود، بیشتر بود. دانسیته نیز با افزایش مقدار پروتئین و کاهش مقدار ژلاتین، کاهش یافت. همچنین با استفاده از روش تجزیه به مولفه های اصلی مشخص شد پذیرش کلی نمونه ها همبستگی بالایی با نرمی، پوشش دهانی و ژله ای بودن داشت.
    کلیدواژگان: موس شکلاتی، پروتئین، PCA
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  • Behrooz Alizadeh Behbahani, Ali Alghooneh, Farideh Tabatabaei Yazdi, Fakhri Shahidi, Mohebbat Mohebbi Pages 201-213
    Introduction
    Avicennia marina, commonly known as gray or white mangrove, is a specie of mangrove tree classified in the plant family Acanthaceae. It is distributed along Africa's east coast, south-west, south and south-east Asia, and southern Iran along the Persian Gulf coast. It grows as a shrub or tree to a height of three to ten meters. Mixture design is one of the most popular smart systems which is based on simulation of linear and non-linear systems using mathematical and statistical techniques, and a useful tool for dealing with completely unknown systems. Chemical preservatives are commonly used for inhibition of pathogens in foods, people are concerned about the side effects of preservatives on their health. Replacement of chemical preservatives with natural substances have a great importance in food preservation. Natural preservatives, as well as, essential oils and plant extracts are suitable alternatives for chemical preservatives. The main purposes of this study are the evaluation of the effects of different combinations of four solvents (water, ethanol, methanol and glycerin) on the efficiency of mangrove leaf extraction using response surface method with mixture optimal design, the optimization of solvent formulation for mangrove leaf extraction, and, finally, the evaluation of the in vitro inhibitory and bactericidal effects of mangrove leaf extract on Listeria innocua ATTC33090 ¡ Enterococcus faecium ATTC 51559 and Escherichia coli ATTC 25992.
    Materials And Method
    Fresh mangrove leaves were prepared from Qeshm Island, Persian Gulf, Iran, in August 2012. Water, ethanol, methanol and glycerin extracts were prepared by adding 50 g of powdered mangrove leaf to 250 mL of the solvent. Extraction was carried out for 48h, in ambient temperature. The mixture of extract and leaf powder was separated by Watman filter paper, then the filtrate was centrifuged in 3000g for 10 minutes and filtered using a 0.45 µm Millipore filter. Finally, in order to separate the solvent and concentrated extract, the solutions were evaporated using a rotary vacuum evaporator. The concentrated extract was stored in dark aluminum containers at 4°C. In this study, the effects of water, ethanol, methanol and glycerin at five levels (0, 31.25, 83.33, 125 and 250 ml) on efficiency of mangrove leaf extraction by mixture optimal design has been investigated. Modeling and optimization has been carried out by Scheffe polynomial. The antimicrobial activity of mangrove leaf extract was evaluated using disk diffusion method. The minimum inhibitory concentration (MIC) of mangrove leaf extract was determined using serial dilution tubes. For each extraction method (based on solvent, Water, Ethanol, Methanol and Glycerin), 8 serial concentrations (2, 4, 8, 16, 32, 64, 128, 256 mg/mL) and 1 control tube of mangrove leaf extract were prepared in Mueller-Hinton broth. The minimum bactericidal concentration (MBC) of mangrove leaf extract was determined using serial dilution tubes.
    Results And Discussion
    The Results indicated that Scheffe polynomial model was highly significant for prediction of efficiency of mangrove leaf extraction (R2 and R2adj values equal to 0.940 and 0.8447, respectively and The lack-of-fit tests did not result in a significant, also F-value (14.62) indicated that the model is sufficiently accurate). The optimum formulation was found as following: glycerin (0 ml), water (28.22 ml), methanol (59.83ml) and ethanol (161.95 ml) respectively. Maximum of antimicrobial effect on Listeria innocua and highest resistance against mangrove leaf extract on Escherichia coli were observed. Increasing concentration of mangrove extracts had a significant effect (p
    Conclusion
    Finally, the results showed that mangrove leaf extract had a notable antimicrobial effect on the studied strains “in vitro”. More “in vivo” studies seem to be required in order to determine the best extract dosage which leads to inhibition of microbial infection.
    Keywords: mangrove plant, optimization, mixture design, inhibition zone diameter
  • Mohammad Mehdi Heydari, Seyed Mehdi Nassiri Pages 214-225
    Introduction
    Given that fruit drying is one of the best economical storing methods, in the present study attempt has been made to apply a commercial drying method, namely passing warm air through fruit in a cabinet drier, to pinpoint the change in textural properties of pear fruit during drying at different inlet air temperature and velocity levels. The outcomes of the study can be used for optimizing the drier operation during drying (intelligent driers) to keep suitable textural properties of final product for those who use sweet dried fruit as sweetener due to diabetic issues.
    Materials And Method
    Pear fruits, Shah Miveh cultivar, were collected form a garden near Isfahan city and carried to the laboratory carefully. Experimental samples with 2×2.5×2.5 cubic centimeter dimension were prepared from upper part of pear fruits. A conventional cabinet drier was used for drying the pear cubes with adjustable inlet drying air temperature and velocity. Air temperature and velocity were adjusted at three levels of 40, 50 and 60 oC, and 0.5, 1 and 1.5 m/s, respectively. Initial moisture content was measured by gravimetric methods and samples weight loss measured during drying by an online system comprising hooked type balance with ±0.001 accuracy. Dried samples were then subjected to texture profile analysis (TPA) with Instron (Santam-STM 20). Two-bite test was performed with 20 mm diameter aluminum probe, at 1 mm/s speed rate for 5 mm deformation. Textural properties of samples such as hardness, cohesiveness, adhesiveness, springiness and chewiness were drawn from force-time curve. Textural properties were measured at five sample moisture contents of 82, 66, 51, 35 and 20 percent (w.b.). Data were analyzed according to the factorial experiments based on completely randomized design by SPSS software (version 16), and the means were compared by Duncan multiple range test at 5 percent of significance.
    Results And Discussion
    Mean comparison of drying time significantly affected by air temperature and velocity, and the effect of temperature was more than air velocity. Results revealed that textural properties of samples have changed during drying process and these changes were related to drying conditions. Hardness decreased exponentially and adhesiveness decreased linearly as fruits were being dried, whereas springiness and cohesiveness increased linearly. Chewiness followed a parabolic trend, reached to the peak in the range of 40 to 50 % moisture content levels (wet basis). ANOVA showed that drying air temperature had significant influence on hardness, springiness and chewiness, while its influence on adhesiveness and cohesiveness was not significant. Moreover, it was found that air drying velocity affected all aforementioned properties. Having considered the results of dried pear chewiness, the minimum chewiness (0.46 J) took place at air drying temperature of 40 ˚С and velocity of 1m/s, and therefore it is recommended as the best drying condition. Drying time period at this condition was measured nearly 33.5 hours, which was approximately 24 hours more than the shortest one in the drying condition of 60˚С and 1.5 m/s and 6.5 hours lower than the longest one in drying condition of 40˚С and 0.5 m/s.
    Keywords: Cabinet drier, Drying, Pear fruit, Texture properties
  • Azam Ayoubi, Naser Sedaghat, Mehdi Kashaninejad, Mohebbat Mohebbi, Mehdi Nassiri Pages 226-238
    The purpose of this research was study effect of drying conditions (temperature at three levels of 60,70, and 80 oC, air velocity at two levels of 1/5 and 2/5 m/s, and four pretreatments including potassium carbonate and paksan oil, olive oil, hot water and no pretreatment (control)) on drying grape process and quality of raisin including rehydration, shrinkage, hardness and browning index. The results showed that temperature, air velocity and pretreatment have significant effects on drying rate and quality of raisin. Drying rate increased with increasing temperature and air velocity and with application of preatreatment. The best values of hardness (0.73 N), shrinkage (81/04%) and the least value of browning index (0/157) were related to dried raisin at 60 oC and most value of rehydration (1/266) was related to dried raisin at 70 oC. Air velocity just significantly affected on browning index. Increasing air velocity decreased browning index. Also between used preatreatments , potassium carbonate and paksan oil caused best physicochemical results.
    Keywords: Air velocity, Browning index, Drying, Drying rate, Raisin
  • Samaneh Pazhouhanmehr, Reza Farhoosh, Reza Esmaeilzadeh Kenari, Ali Sharif Pages 239-249
    Introduction
    Common Kilka (Clupeonella cultriventris caspia) is one of the most abundant and industrial fish in the Caspian Sea located in the north of Iran, and also the best source of long-chain polyunsaturated fatty acids, especially EPA and DHA [Fazli et al., 2009, Connor, 2000]. Due to high level of the ω3 : ω6 ratio and polyene index, the common Kilka oil is expected to be highly susceptible to oxidation [Pirestani et al., 2010]. The interesting antioxidative characteristics of the oils and unsaponifiable matter (USM) extracted from the kernel and hull of bene fruit (Pistacia atlantica subsp. Mutica) attracted our attention to use them as natural alternatives for stabilizing the common Kilka oil and compare with BHT and α-tocopherol [Farhoosh et al., 2012].
    Materials And Method
    The ripe bene fruits were collected from the fields of Islamabad in the Ilam province. After drying and also grounding to powder, the oils from the kernel (BKO) and the hull (BUO) of bene were extracted with n-hexane (1:4 w/v). Moreover, the USM content of the kernel (UKO) and hull (BHO) oils of bene were determined by the method described by Lozano et al, 1993. Chemical compositions of the bene oils’ unsaponifiable matter were determined by a thin-layer chromatography [Lercker and Rodriguez-Estrada, 2000]. Crude Kilka oil was purified by a multilayer column chromatography to eliminate the majority of pro-oxidant and antioxidant compounds normally present in it. The purified Kilka oil (PKO) was blended separately with 1 and 2% (w/w) of the antioxidative oils (BKO and BHO), 1 and 1.5% (w/w) of the oils’ unsaponifiable matter (UKO and UHO), and 100 mg/kg α-tocopherol and BHT and then exposed to the following stability test. Fatty acid composition of the oil samples was determined by gas-liquid chromatography [Sharina and Jumat, 2006]. The iodine value (IV) was measured according to the AOAC Official Method 920.158 [AOAC, 2005]. A colorimetric method was used to determine total tocopherols (TT) content [Wong et al., 1988]. Total phenolics (TP) content was spectrophotometrically determined using Folin–Ciocalteau’s reagent [Capannesi et al., 2000]. A Metrohm Rancimat model 743 (Herisau, Switzerland) was used for the oil/oxidative stability index (OSI) measurement in airflow rate of 20 L/h. The temperatures in measuring of the OSI were 60 °C for the PKO, OSI60, and 120 °C for the BHO and BKO, OSI120 [Farhoosh et al., 2008a; Mendez et al., 1996]. The analysis of variance (ANOVA) was carried out according to MStatC and SlideWrite software. Significant differences between means were determined by Duncan’s multiple range tests; p values less than 0.05 were considered statistically significant.
    Results And Discussion
    The initial quality parameters of the PKO, BHO and BKO are shown in Table 1. The PKO was mainly constituted of MUFA, followed by the SFA and PUFA, and there was no measurable contents of TP, TT and USM fractions in it. The PKO showed a PUFA/SFA ratio higher than the minimum value recommended by the UK Department of Health (0.73 vs. 0.45) [HMSO. UK., 1994]. The ω3/ω6 ratio of the PKO was relatively similar to that of Indian mackerel (Rastrelliger kanagurta) (1.60 and 1.67, respectively) (Table 1) [Osman, Suriah, & Law, 2001].
    The IV, as an indicator of the oil unsaturation and resistance to oxidation, for the PKO (114.99) was much lower than sardine (156.2) and salmon (165.8) oils [Frankel, 1998; Endo, Tagiri-Endo, & Kimura, 2005].
    As can be seen in Table 1, the BKO had higher contents of the USM, tocopherols and phenolic compounds than the BHO. The valuable effects of minor components especially polyphenols and tocopherols of the BHO and BKO on the oxidative stability of vegetable oils have been shown in the previous studies [Farhoosh et al., 2012]. The differences in the fatty acid composition and the amounts of minor components led to the greater OSI120 of the BKO than the BHO (9.46 vs. 7.91 h).
    The major constituents of the UHO and UKO were tocopherols and tocotrienols (Table 2). These compounds, which are particularly important functional constituents of the USM of vegetable oils, have nutritional importance for human health and render antioxidative properties [Lercker and Rodriguez-Estrada, 2000].
    The OSI60 values of the PKO as affected by the antioxidative compounds are presented in Fig 1. As shown in Fig. 1, the OSI60 of the PKO (1.66 h) significantly increased in presence of the antioxidants added. Moreover, the highest significant stabilizing effect belonged to the UKO 1.5%, so that it was able to increase significantly the OSI60 up to 8.12 fold (OSI60, 13.48 h) (p
    Keywords: Oxidative stability, triacylglycerols, bene oil, Kilka, unsaponifiable matter
  • Mohammad Farhadi Chitgar, Mehdi Varidi, Mohammad Javad Varidi, Ahmad Balandari Pages 250-260
    Introduction
    Extensive researches into native plants as a source of functional food have been conducted over the resent years. Meanwhile, barberry has been utilized as one of the main medicinal plants in Iran and many other countries, from the past decades. Currently, it has been known pharmaceutical active ingredients like berberin have wide application in pharmaceutical industry. The genus of Berberis includes about 450–500 species of deciduous or evergreen shrubs in which four species B.integerrima, B.crataegina, B.vulgaris and B.orthobotrys are found in Iran. Iran is the first largest producer of barberry (B.vulgaris) in the world. Apart from that, other species in different parts of Iran grow in wild conditions. B. Integerrima is a thorny shrub with fragile branches to a height of 1 to 3 meters. Its fruits are small and red with a mild sour taste. There are 1-4 small oblong seeds inside. The changes in this species are important and can produce hybrid with other species. B. Integerrima fruits are consumed fresh or used in the preparation of traditional foods. Barberry fruit, which contains large amount of anthocyanins, can be used as an alternative to synthetic colorants. In addition, aqueous extract of barberry has beneficial effects on both cardiovascular and neural system suggesting a potential use for treatment of hypertension, tachycardia and some neuronal disorders, such as epilepsy and convulsion. The physical properties of barberry genotype are important to design the equipment for sorting, transportation, separation, processing and packaging. Identification of the chemical characteristics of Berberis genotype can lead in using them in the pharmaceutical or food industries. Therefore, in order to introduce these native species, physicochemical characteristics of three wild barberries were evaluated
    Materials And Method
    Three native seed genotypes from Semnan province were manually collected from Research Institute of Food Science and Technology (Mashhad). The harvested fruits were instantly stored inside ice box to minimize damages and transported to the laboratory. Over ripened and damaged fruits were separated. Some physical properties (size, geometric mean diameter, sphericity, area, mass and the weight ratio of seeds to fruit) of fruits were determined using 100 repetitions at the natural moisture content of fruits. Chemical properties of samples were determined as follows: total anthocyanin content by the pH differential, total phenolic content by modified Folin–Ciocalteu method, mineral elements amounts such as Potassium(K), Sodium (Na) and Calcium (Ca) by Flame Photometer and microelements (Fe, Cu, Mg, and Zn) by Atomic Absorption Spectrophotometer, Moisture, crude oil, crude protein, ash, reducing sugar, water-soluble extract, pH and acidity were determined according to Indrayan et al,1989 and Iranian National Standard No. 2685. All experiments (except physical properties) were repeated at least three times and results were expressed as mean ± SD. The significant differences between mean values of juice samples were determined by analysis of variance (one way-ANOVA) using Duncan’s test at a significance level of p
    Results And Discussion
    Results showed that in physical properties such as, fruit length there was statistically difference between genotypes. The number of seeds in the three genotypes varied between 1 and 4 numbers. The weight ratio of seeds to fruit was 11.88%, 10.84% and 10.68 in Noshin, Negarin and Parchin genotypes, respectively. All three genotypes contained high amount of protein, total carbohydrate, fat and ash (3.82-5.255%, 21.68-23.97%, 2.04-2.70% and 0.94-1.27%). Noshin contained the highest reduced sugar (8.03±0.222). So, it is sweeter taste than others. In accordance with result, the amount of anthocyanins (950.17-3927.60mg/L) and total phenol (9.75-12.35gr/L) were higher than these fruits in comparison to the other fruits like mulberry and blueberry that represents the health benefits of these wild plants. All the three genotype emerged as good source of minerals, especially K, Ca, Mg and Zn.
    Keywords: Anthocyanin, Barberry, Functional, Physical, Chemical Properties
  • Babak Ghanbarzadeh, Akram Pezeshki, Hamed Hamishekar, Mohammad Moghaddam Pages 261-275
    Introduction
    The encapsulation of hydrophobic nutraceutical compounds such as fat soluble vitamins in nanoliposomes is a potentially effective way to protect them from from light, oxygen and chemical degradation during the maintenance. One of the potential benefits of liposomal structures is encapsulation of three water-soluble, fat-soluble and amphiphilic compounds and use of natural food ingredients such as lecithin with beneficial effects, in their production. In this study, the effect of lecithin-cholesterol concentrations on particle size, particle size distribution, encapsulation efficiency (EE) and physical stability of vitamin A palmitate loaded nanoliposome during the storage time were explored to get the optimized formulation
    Materials And Method
    Materials: Phospholipid (L-α-granular Lecithin) with purity of 99% was obtained from Across (USA). Cholesterol with 95% purity was supplied by Merck (Germany). Other chemicals were analytical grade and procured from Sigma (Merck¬ Chemical Co. Darmstadt, Germany).
    Methods
    Nanoliposomes were prepared from different concentrations of lecithin–cholesterol (60:0, 50:10, 40:20 and 30:30 mg) by thin-film hydration–sonication method. Lecithin and cholesterol were dissolved in absolute ethanol and then dried with vacuum evaporator. Prepared dried lipid film hydrated by aqueous phase. The resultant suspension was mixed for some time (Hydration-dehydration). Due to existence of water inside the lipid film, osmotic pressure runs the water into bilayer membrane and causes separation of lipid film and then liposomes were produced. In this method, mixture of Multilamellar Vesicles (MLVs) and Small Unilamellar Vesicles (SUVs) liposomes were produced. Reduction in particle sizes of prepared liposomes was done by ultra sound probe sonicator. The average diameter and span value of the particles were determined using particle size analyzer (Wing SALD 2101, Shimadzo, Japan), at 25°C and was calculated according to the DeBroukere mean in the Equation (1): The span value is an index helpful to evaluate the particle size distribution and calculated applying the following Equation: Morphology of the nano-carriers was observed using trans- mission electron microscopy (Zeiss-Leo 906 TEM (Germany). To determine the zeta potential of nano liposomes loaded vitamin A, Zeta siyzer device (Nano-ZS -Malvern England) was used at 25◦C temperature. Estimation of encapsulated vitamin in nanoliposomes (%EE) was carried out using HPLC (Knauer,Germany) equipped with a UV detector, C-18(10 mm 25mm_4.6 mm) column and acetonitrile– methanol (70:30%,v/v) as mobile phase and was calculated using the below equation %EE= (Encapsulated Vitamin A)/(Total Vitamin A) ×100
    The stability of vitaminA loaded-nanoliposomes was assessed by determining the average particle size at 4 °C over storage time and studying the leak out of the vitamin from the nanoliposomes after one month(1,7, 15and 30days)of storage at 4 °C by the below equation %Stability = (Remained Vitamin A)/(Initial encapsulated Vitamin A) ×100
    Results And Discussion
    Results showed use of sonication in completion thin-film hydration method, induced production of monomodular nanoliposomes with uniform distribution The particle size was in the range of 76-115nm and particle size distribution was monomodular (span= 0.6- 0.88). In agreement with particle size results, TEM image showed that the vesicles are in the form of small unilamellar vesicles by bilayer nature. In all concentrations of lecithin-cholesterol, obtained EE was low and by increasing the lecithin concentration, loading capacity of nano liposomes increased. By increasing the lecithin concentration, more vesicles are produced which causes increase in internal volume of liposomes and bio actives concentrate, consequently loading capacity of nano liposomes increased. By tightening of the membrane by cholesterol, entrapment efficiency of hydrophobic active compounds such as vitamin A palmitate reduces. Also probably existence of cholesterol in liposome membrane inhibits of rupture and changes in liposome membrane. Overall, increasing the ratio of cholesterol /lecithin had no significant effect on particle size but decreased encapsulation efficiency of vitamin A palmitate to 10.23%. Addition of cholesterol effected on stability of the particle size of nanoliposomes and also led to reduction encapsulation efficiency of vitamin A palmitate. Incorporation of cholesterol and vitamin A palmitate into the liposome structure was increased the zeta potential from -29 to -58 mv and improved electrostatic stability. 50-10 mg ratio of lecithin-cholesterol concentration was used for preparation of optimum formulation of nanoliposome by monomodular and small size distribution (76 nm, span=0.74) and encapsulation efficiency (15.8%). Stability of vitamin A in nano liposome with 50-10 mg lecithin-cholesterol, was almost low (32% reduction during storage time), may be due to increasing fluidity of membrane. Permeability of vitamin A into phospholipid chains causes reorientation of acyl chains which leads to fluidity of membrane and exit active compound from nano carrier and more its hydrolytic degradation and oxidation. While the use of thin film hydration method using ultrasonic waves, is successful way in producing nanoscale particles of vitamin A palmitate nanoliposomes that are stable and decrease over time, but due to low efficiency and low sustainability of encapsulation, use of other nanocarriers for encapsulating of vitamin A palmitate is recommended
    Keywords: nanoliposome_vitamin A palmitate_encapsulation_stability_nano carrier
  • Mahboobeh Kashiri Pages 276-285
    Introduction
    Antimicrobial packaging is a novel preservation technology that is designed base on releaseing of active agents incorporated with the packaging polymer into the packaged food or the surrounding environment for improveing the quality and food safety. Zein, water insoluble proteinof cornof corn, reported to be thermoplastic material with high tensile strength, excellent hydrophobic film, biodegradability.Zataria multiflora Boiss. (Z) is a thyme-like plant belonging to the Laminaceae family that geographically grows wild in central and southern parts of Iran. Antimicrobial activity of Z essential oil (ZEO) has been successfully tested against foodborne pathogens. Most of the studies on antimicrobial packaging mainly focused on the initial screening of newly developed films for ZEO in laboratory media and quantifying the bacterial reductions obtained during storage for different types of packaged food products. it is really important to know the variation in antibacterial activity of the agents when incorporated into the packaging film from its original activity in order to establish the levels that need to be incorporated for effective bacteria inhibition, hence The aims of the present study were to investigate the antimicrobial potential of ZEO incorporated zein film against pathogenic microorganisms inoculated in olivier saladto provide evidence of their applicability in the design of active food packaging systems.
    Materials And Method
    Z was collected in the Shiraz province of Iran and extected by using clevenger type apparatus. Chemical composition ZEO was analyzed by gas chromatography.Antibacterial activity of ZEO was studied in the liquid (direct contact) and solid media (vapour phase) against Listeriainnocua and Escherchia coli . Zein powder was dissolved in a hydro alcoholic solution to obtain 16% (w/w) films forming solutions. The solution was stirred for at 80 °C using a magnetic stirrer hotplate. Glycerol (15%) was added to the solution and stirred again for 8 min at 30°Cm, then ZEO was added to the polymer solutions in 5% and 10% with respect to polymer content and stirred for 8 min. Films were obtained by casting, the film forming solutions were extended over it using an extension bar and introduced in a drying tunnel equipped with a heat of 2500 W during 20 min. Control zein films were prepared without active agent. To evaluate the efficacy of developed zein films was tested against two bacteria. Prior to the experiment, a loop of each strain was transferred to 10 ml of TSB and incubated at 37 ˚C for 18 h to obtain early stationary phase cells and100 µl of microorganism were inoculated into tubes with 10 ml of TSB. The tubes were then incubated at 37 °C for 18 h and 4 °C for 5 days. As control, zein film without active agent was also used in every experiment. Antibacterial activity of zein films containing 10% ZEO were evaluaterd for packaing of olivier salad as a real food model for 6 days, by performing serial dilutions with peptone and subsequent plating in Palcam Listeria Selective Agar and Brilliant Green Agar for ListeriainnocuaandEscherchia colirespectively. Plates were incubated at 37 °C for 48 hours.
    Results And Discussion
    GC–MS analysis showed thatthe major compound of ZEO was carvacrol (45.22%). The antimicrobial effects of ZEO in the vapor phase against Escherchia coliand Listeriainnocuaby using the disk diffusion methodshowed that the25 µg of ZEO produced a visible decrease in microbial density retraction zone (). No inhibition was observed with the addition of lower amounts of the antimicrobial agents, therefore 25 µg was the minimum inhibitory concentration (MIC).Activezein films containing 5% ZEOweren’t able to inhibit the growth of the two bacteria in the vapour pase.. When the concentrations of ZEO was increased to 10%, only active films with a diameter of 80 mm (50.24 cm2)provided a retraction zone () against Listeriainnocuaand E. coli. These values were indicative that incorporation of the agent in the zein films produced weaker vapor phase inhibition than its incorporation in the paper disk.The results of this studied showedthat films with 5% ZEO caused a growth reduction of 1.17 log againstListeriainnocuaand 1.14 log against Escherchia coli, while 10% ZEO produced reductions of 2.16 and 2.64 log against Listeriainnocua, Escherchia colirespectively. There was no significantdifference betweenlog reduction values of ZEO incorporated in zein films against Listeria innocuaand Escherchia coli. And also in the liquid media with increasing the concentration of ZEO in zein films, the log reduction values were increased against both bactreia. Despite of the excellent antibactrerial effect of ZEO in zein films in direct contact, bio active zein films were not effective enough for reducing the contamination of packaged Olivier.
    Keywords: Antibacterial packaging, Zein, Essential oil
  • Maryam Azizkhani, Fahimeh Tooryan, Maryam Boreiry Pages 286-295
    Introduction
    Mold growth on cheese is a common problem for cheese manufacturers during ripening and curing, as well as for the retailer and consumer during refrigerated storage. Listeria monocytogenes has gained increasing attention as a pathogen of public health importance owing to large numbers of foodborne outbreaks of listeriosis. Ingested by mouth, Listeria is among the most virulent of foodborne pathogens with up to 20% of clinical infections resulting in death. Various types of foods, mostly dairy products such as cheese, have been associated with these outbreaks and there is considerable interest in stopping this upward trend. As a result of the negative consumer perception of chemical preservatives, attention is shifting towards natural alternatives. A technique that has been used since ancient times to prevent fungal growth on foods such as cheese involves physically rubbing the product with certain herbs or spices or their oils. Therefore, 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. In this research, the effect of salvia and basil essential oils (EOs) on Listeria monocytogenes and Aspergillus flavus in Iranian white cheese has been investigated.
    Materials And Method
    Commercially available EOs from basil and salvia were used in this study (Pranarôm International, Ghislenghien, Belgium). EOs were analyzed by gas chromatography mass spectrometry (GC-MS). A broth microdilution assay was employed to determine the lowest concentration (MIC) in which visible growth of the bacterium is inhibited. The concentration of EO present in those wells that yielded plates with no visible colonies was considered to be the minimum bactericidal concentration (MBC). The effects of EOs on radial growth of fungal mycelium were assayed using an agar dilution method. The lowest concentration which inhibited the growth of the fungus was considered to be the minimum inhibitory concentration (MIC) whereas the lowest concentration of EO which killed the fungus (no growth observed on fresh medium) was taken to be minimum fungicidal concentration (MFC). Iranian ultra-filtered white cheese was produced in a commercial factory with different concentrations of EOs and the effects of EOs on bacterial and fungal growth in cheese during shelf-life were determined. Also, eight trained panellists performed sensory analyses. The panellists scored for colour, odour, flavour, overall acceptability and texture using a 9-point hedonic scale (1, dislike extremely to 9, like extremely).
    Results And Discussion
    Main components of salvia EO included linalyl acetate and linalool and of basil EO consisted of linalool and α-cadinol. The MIC and MBC of salvia were obtained %0.015 and %0.02 and of basil %0.05 and %0.06, respectively, against L. monocytogenes. In the current report, L. monocytogenes was neither eliminated nor completely inhibited by basil EO, but salvia EO was able to inhibit its proliferation in cheese. The effect was even more pronounced with 1% salvia oil compared to 0.5% or 0.75%. Basil EO at a concentration of 1% caused a 7-day delay in the growth of L. monocytogenes. A growth delay of this type is particularly useful in terms of food safety for the short-term storage of products but not on prolonged storage as Listeria may reach high levels in foods over longer periods. MIC and MFC of salvia were %0.5 and %0.65, and of basil % 0.6 and %0.8, respectively, against A. flavus. At %0.35 and %0.5 the sporulation was inhibited by salvia and basil EOs, respectively. In the present study, no growth of A. flavus was observed in the presence of 1% of salvia EO, and colony diameter attained less than 5mm by the 21st day of cold storage in cheese samples treated with 1% basil EO. Also, the bacterial growth reduced up to 6 log cfu/g of cheese. EO of basil showed weaker antimicrobial effect compared to salvia EO. Cheese samples with different concentrations of EOs were evaluated and compared to the control sample to ascertain consumer acceptability for it. Significant differences were detected among samples containing EOs and the control sample in odour, color and texture, but the samples containing 0.75% and 1% of salvia EO were significantly impaired in both odour and taste as compared with the other samples. With regard to the overall acceptability, the cheese sample containing 0.75% of basil EO was the highest acceptable sample. Generally, it is well known that in complex systems such as cheese, several ingredients interact with each other and affect the sensory properties.
    In conclusion, the EO of salvia showed the greatest effect on limiting microbial growth. Both EOs could have potential for commercial use in improving the preservation of these products without the need for propionates or other synthetic additives. Further research could examine the utility of the combined application of basil and salvia EOs in different dairy products such as different types of cheese, as well as the use of different quantities/ratios for optimization of their antimicrobial effects.
    Keywords: Cheese, Ocimum basilicum, Salvia sclarea, Listeria monocytogenes, Aspergillus flavus
  • Farideh Sharifi, Latifeh Pourakbar Pages 296-307
    Introduction
    Numerous biochemical reactions in human body produce active oxygen which is able to destroy biomolecules. This destructive effect of free radicals can be blocked by antiradicals. The role of free radicals in causing a noticeable number of disease has been proved. Anti-oxidants defend against these oxidative destructions. One of the best natural resources of oxidants are phenolic compounds in plants. Phenolic compounds by giving electrons to free radicals, restrain lipid oxidative reactions. Chemical antioxidants have been using a lot in food industrysuch as BHT, BMA, TBHQ and propyl gallate that their destructive and carcinogenesis effects on human body have been proved. Therefore, nowadays, the consumption of medicinal plants and their phenolic compounds as natural resources of antioxidants has been highly recommended. Different solvents and a variety of extraction methods can be used for extracting anti-oxidative compounds from plant tissues. Polarization degree of different solvents will effect on the amount of extracted phenolic compounds. Berberidacease family has a significant use in medicine and industry. There are biological activities in Barberry and it's highly used in food and medical industries. The main alkaloid of barberry is Barberine which has the anti-oxidative and anti-inflammatory properties and decreases blood pressure, hypoglycemia and lipid. Phenolic compounds and anthocyanins are the most important secondary active nutrients in Barberry. Barberry's extract and its bark root are rich in anti-oxidative and phenolic compounds. Berberis Integerrima × vulgaris has been studied in this research. The aim of this study was to determine the best solvent for extraction, the amount of phenolic compounds, anti-radical activity and anti-oxidative capacity in different extracts of fresh barberry which is gathered from Qamchoqai zone, Bijar, kordestan province.
    Materials And Method
    For this study, Barberries were collected from Qamchoqai zone located in Bijar, Kurdistan, Iran. They had been maintained in freezer till we started to examine them. Then, we prepared the ethanol, methanol and water extracts of these frozen Berberis. The total Phenol and Flavonoid contents of extracts according to the method of UV-VIS, Total antioxidant activity content of extracts by using three different methods including scavenging activity of DPPH , NO, reducing power assay and the capacity of inhibit lipid peroxidation by thiobarbituric acid were determined.
    Results And Discussion
    In conclusion, this investigation demonstrates that Barberry is a rich source of phenolic compounds and antioxidant capacity. The aqueous extract showed the highest total phenol content (48/98±0/49 mg/g (wet weight)) and scavenging power of Nitric Oxide radical activity(%723/6±64/56) and the methanol extract showed the highest flavonoid content (1/93±0/033 mg/g(wet weight)), DPPH scavenging effect (%44/62±0/99), reducing power (5/89±0/42 mmol/g(wet weight)) and MDA content (37/12±0/79 mmol/g(wet weight). The type of solvent used for extraction has significant effect on phenolic compounds and flavonoids. Methanol extract has the minimum amount of phenol in fresh barberry, but methanol is a good solvent for flavonoids in barberry. The result of anti-oxidative effects in different extracts of barberry according to MDA scale shows that the water extract has the maximum amount of anti-oxidative activity. These activities in extracts are because of the existence of phenols which prevent lipid oxidation by removing free radicals and stop the increase of Malondialdehyde. In this study, Methanol extract has the maximum amount of anti-radical activity. These different results in extracts are due to the different phenolic compounds and flavonoids in them. Among extracts, water exract has the maximum capacity in trapping nitric oxide radical. Anti-radical activity against NO radicals probably is done by anti-oxidative compounds in barberry which competes with O2 over NO. In term of reduce power, extracts didn’t have significant difference with each other. FRAP and DPPH method was the same result. This means that the methanol extract than other extracts showed higher antioxidant activity. In the extraction of phenolic compounds, Organic solvents especially methanol, was more effective than water and possibly "phenolic compounds derived regenerative better by methanol extract. Results showed that aqueous and alcohol extracts of Berberis Integerrima×Vulgaris can act as a natural antioxidant and after complimentary expriments, it can be used in food and medecine industry
    Keywords: Berberis Integrrima×Vulgaris, DPPH, Flavonoid, FRAP
  • Afshin Faridi Esfanjani, Seid Mahdi Jafari, Elham Assadpoor, Habibollah Mirzaei Pages 308-317
    Introduction
    Controlling and targeting release of bioactive compounds have a key role in improving their functional properties such as antioxidant and anti-disease activities. Encapsulation is one of the best methods for protection and controlling release of bioactive ingredients. Indeed, in this process, protection and controlling release of ingredients as core materials are performed by surrounding of them via variety of wall materials. Emulsions are most popular encapsulation systems that are classified in variety types such as single layer emulsion, multi-layer emulsion, doubleemulsion, and etc. Hydrophilic bioactive compounds can be loaded in inner aqueous phase of water in oil in water (W/O/W) double-emulsions. The stability of doubleemulsions is low due to presence of two interfaces in them.Applying a thermodynamically stable W/O emulsion (e.g., micro-emulsion) as a primary emulsion and using of complex biopolymers as emulsifier and stabilizer in outer phase of doubleemulsions can improve their stability (Dickinson, 2011; Boyer et al, 2012).
    Saffron bioactive compounds include crocin, picrocrocin, and saffranal are widely used for a variety of functional and healthy goals in food and pharmaceutical industries. These compounds have many different functions, including anti-carcinogenic, anti-oxidant, anti-depressant, anti-apoptotic, anti-tussive, anti-nociceptive, anti-inflammatory and anti-thrombotic properties (Moraga et al, 2004).
    In the present study, our main goal was kinetically evaluated release of crocin, picrocrocin and saffranal from inner phase to outer phase of doubleemulsion during 22 days storage by Zero order, Fist order, Higuchi, and Hixson-Crowell.
    Materials And Method
    Saffron was provided from Torbatheydariyeh farms, Khorasan-e-razavi, Iran. Sunflower oil and sodium azide were purchased from FRICO (Sirjan, Iran) and Sigma-Aldrich (St. Louis, USA), respectively. Whey protein concentrate (80% protein) and sorbitanmonooleate (span 80) were obtained from Sapoto cheese (USA) and Merck (Germany), respectively. Maltodextrin was obtained from Qinhuangdao starch Co. (DE 16-20, China) and citrus pectin with a degree of methyl esterification of 71.1% and galacturonic acid >65% was purchased from MP biomedical (Netherland). All other chemicals used in this study were of analytical grade.
    For extraction of crocin, picrocrocin and saffranal, a total of 10 grams of saffron sample was macerated in 150 mL of water in a glass bottle, covered with aluminum foil (to prevent direct exposure to light), and was placed in an incubator shaker (Kavooshmega, Iran) for 24 hours at 30oC. Then, this solution was homogenized (10000 rpm for 10 minutes, HeidolphSilentcrusher, Germany) for maximum extraction of saffron compounds. Finally, the extract was filtered under vacuum by using a Whatman No. 1 (11 mm) filter paper, and kept in the freezer at -18oC prior to any examination. ISO/TS 3632 procedure (2003) was used for the measurement of saffron compounds.
    The doubleemulsions were prepared in two-step: (a) Frist, primary W/O micro-emulsions were produced by two formulations: 60:30:10% and 62:33:5% of sunflower oil, span 80, and saffron extract, respectively.
    (b) Then, the W/O micro-emulsions was gradually added into the outer aqueous phase contains why protein concentrate (WPC)/maltodextrin or WPC/pectin/maltodextrin while blending by a homogenizer (12000 rpm for 5 minutes at 10oC, HeidolphSilentcrusher, Germany) and then these coarse emulsions were further emulsified using mentioned homogenizer (15000 rpm for 8 minutes at 10oC). All doubleemulsions were composed of 25% primary emulsion and 75% outer aqueous phase
    Droplet size of doubleemulsions after one day and 22 days storage weremeasured using Zetasizer (Malvern Instruments, Worcestershire, UK).
    The released components in the outer aqueous phase were measured by evaluation of encapsulation efficiencyof the ratio of crocin, picrocrocin, and saffranalat a specific time: E (%) = 100- (C2×100/C1) (1)
    Where C2 is the percentage of crocin, picrocrocin and saffranal in outer aqueous phase and C1 equals to the percentage of compounds in inner aqueous phase.
    C2 is a released into outer aqueous phase relative to the total amount present in the outer aqueous phase if all compounds were released (M ∞).
    The viscosity of emulsions was measured using a programmable viscometer (model LVDV -II Pro, Brookfield Engineering Laboratories, USA) and by a ULA spindle.
    The released are kinetly evaluated by Zero order, Fist order, Higuchi, and Hixson-Crowell.
    The experiments were all carried out in triplicate. The collected data were analyzed by one-way ANOVA; the means were compared by the Duncan's multiple range tests at the 5% level through SPSS version 21 (IBM, USA).
    Results And Discussion
    As shown in fig. 1, the droplet size of produced W/O micro-emulsions were lower than 200 nm. In fact, these droplets are water droplets containing bioactive compounds of saffron dispersed within oil phase that surrounded with Span 80 (Fig. 2).Also, it was found that by increase of saffron extract (from 5% to 10%) as dispersed phase in W/O micro-emulsions, droplet size and poly-dispersityindex (PDI) weresignificantly (P
    Keywords: Release, Nanoencapsulation, W, O, W double emulsion, saffron
  • Nasim Pourebrahim, Masoud Yavarmanesh Pages 318-329
    Introduction
    Pistachio nut is one of the popular tree nuts. Among the different species of the genus Pistacia, only the fruits of Pistacia vera attain optimal size to be acceptable to consumers as edible nuts. Contamination of pistachio by Aspergillus species and their mycotoxins is the most important problem for consumption and export of this product. Aflatoxins are potent toxic, carcinogenic and mutagenic secondary metabolites primarily produced by two fungal species, Aspergillus flavus and Aspergillus parasiticus. Aspergillus flavus produces AFB1 and AFB2, while Aspergillus parasiticus produces AFB1, AFB2, AFG1 and AFG2. Among four main groups of aflatoxins, AFB1 is the most potent carcinogenic compound. Therefore, identification of toxigenic fungi is necessary for evaluating the foods quality and the presence of mycotoxins. The current methods being used for assessing fungi presence in foods based on cultivation methods and microscopic characteristics are time-consuming and labor-intensive. Recently, molecular techniques such as polymerase chain reaction (PCR) due to high sensitivity, specificity and rapidity has been introduced as powerful tools for detecting toxigenic fungi. Many genes involved in the biosynthesis of these mycotoxins have been identified and their DNA sequences have been published. PCR methods can be used to detect of aflatoxigenic Aspergilli based on structural genes (nor1, ver1 and omtA) encoding key enzymes in aflatoxin biosynthesis pathway and the regulatory gene aflR.
    Materials And Method
    Pistachio samples were collected from different cultivation regions of two towns including Gonabad and Feyzabad. Samples were packed in sterile plastic bags and immediately transferred to the laboratory. The moisture content of samples was determined using thermal method and drying in at 95-100°C. Among fungal isolates 30 Aspergillus genus were detected and purified by cultural-based methods using PDA (potato dextrose agar) medium. Colonies of the fungus were transferred to PDB (potato dextrose broth) medium and incubated for 5 days at 28°C with shaking at 150 rpm. The mycelium was frozen in liquid nitrogen and ground to a powder for later DNA isolation. DNA was extracted with CTAB (cetyl trimethyl ammonium bromide) extraction buffer, then was purified with organic solvents such as chloroform/isoamyl alcohol and finaly was precipitated by isopropanol. Aspergillus genus were detected using polymerase chain reaction by specific primer pair Asp1/Asp2 for amplification of 18S rRNA region. Furthermore, aflatoxigenic genes were detected by three sets of primers (APA-450/APA-1482, ver1/ver2 and OMT-208/OMT-1232). PCR was performed in a volume of 25 µl containing 0.5 µl of each primer, 12.5 µl of Taq DNA polymerase master mix red, 10.5 µl of sterile distilled water and 1 µl of genomic DNA as template. A PCR consisted of an initial denaturing step of 5 min at 94°C followed by 35 cycles (30 s at 94°C, 35 s at 65°C and 40 s at 72°C) finished by a final extension step at 72°C for 10 min. The PCR products were analyzed by electrophoresis on a 1% agarose gel in TBE.
    Results And Discussion
    Among fungal isolates 30 Aspergillus genus were detected using microscopic characterstics and colony color. Under the microscope, conidia were one-celled, spherical, hyaline or pigmented and they formed long chains. 12 and 4 out of 30 samples had omtA and ver1 genes respectively. No observation was found for aflR regulatory gene in the fungal isolates. The results showed that although some isolates had one or two structural genes in the aflatoxin biosynthetic pathway, they could not produce aflatoxin due to not having any aflR gene. Coefficient of correlation was calculated to find the relationship between the existence of Aspergillus molds and aflatoxigenic genes in pistachio. The statistical results indicated that there is a significant correlation between the enumeration of Aspergillus molds and the existence of genes (omtA and ver1) in different moisture domains (p> 0.05) while no significant correlation was identified between the enumeration of Aspergillus molds and the existence of genes in different domains of enumeration of mesophilic bacteria, yeasts and molds. Contamination of nut seeds by fungi occurs during growth, harvesting, transport and storage. The production of aflatoxin is affected by different factors, such as genetic properties of the producing fungi, temperature, moisture content, the chemical composition of food and antimicrobial agents produced by other microorganisms. Water stress and temperature are the most relevant environmental factors which influence fungal growth and mycotoxin production. Other studies showed that there was a good correlation between the expression of an early structural gene (aflD) and aflatoxin B1 production in peanut seeds. Also previous studies have shown that there was a significant relationship between A.flavus contamination in the peanuts and pistachio with high humidity (p> 0.05). Since other factors such as temperature, pH and chemical composition of pistachio can affect the existence of Aspergillus molds and expression of aflatoxigenic genes, the influence of these factors on existence of Aspergillus molds and genes involved in aflatoxin biosynthesis pathway need to be investigated.
    Keywords: Aspergillus, Aflatoxin, Pistachio, Aflatoxigenic genes, Polymerase chain reaction
  • Saeed Mirarab Razi, Mohebbat Mohebbi, Mohammad Hosein Haddad Khoda Parast, Arash Koocheki Pages 330-339
    Introduction
    Proteins are widely used in food industry because it has functional properties such as formation and stabilization of foam systems. These molecules had surface-active properties. They rapidly adsorb at interface during the foaming processes and form a film around gas bubbles. The bulk properties has important role in the stabilization foam system. It has been shown that protein adsorption is influenced by molecular properties, such as size, shape, surface hydrophobicity, conformation, and charge and conditions in the bulk solution, such as bulk concentration, pH and ionic strength. The foaming properties depend on many intrinsic factors (size, structure of protein, hydrophobicity, surface potential, charge, etc.); and environmental and processing factors (protein concentration, pH, temperature, addition of other ingredients, etc.) Foams are colloidal systems in which gas phase dispersed in an aqueous continuous phase. Foaming operation is usually devoted to produce lighter products, modify the appearance and the texture of food products, therefore, it be used to production new products adapted to consumer choice and needs, using air as a zero-cost component. Microstructure has fundamental role in foam properties. At foam based products, bubble size is of most importance at the foam properties, because it influences on texture, the mouth-feel and the stability of the aerated product. Many food products have aerated structure. In these foods, the gas phases, forms small bubbles that modify microstructure and mouth feel properties of product. Aerated desserts have shown a great market potential, which is dependent on consumer behavior, interested in lighter and healthier products. Food products based on foam structure such as chocolate mousse have good marketing; therefore deep knowledge about their properties is important. Mousse is an aerated dessert with stabilized foamy structure which little attention has been paid to industrial production. Although, the most popular mousse flavor is chocolate, orange, lemon and strawberry have good marketability.
    Materials And Method
    This study follows two important objectives; first, the effect of different amount of gelatin concentration and sodium caseinate on rheological, physical and sensory properties of chocolate mousse is investigated. Then, the relationship this parameters was discussed on the basis of laboratory results using PCA method. Chocolate mousse was include of, Gelatin(Bangladesh, type B, bloom 160-180), Cacao powder(Cargill Co., Netherlands), Whipped cream(Mahrang sahar shargh CO., Iran 27% fat), Sugar(Fariman, Iran) and Sodium caseinate (Milad, Iran). Chocolate mousse samples were prepared with different amount of gelatin (1, 2 and 3 gr) and sodium caseinate (1, 2 and 3 gr) concentrations. Gelatin was first dissolved in hot water. Next, cacao powder and sugar were stirred in hot water and added to whipped cream agitated by Gosonic home mixer with speed 5400 RPM for 3 minutes. Then, Sodium caseinate was mixed in distilled water for 2 minutes and added to mixture prepared. Finally, mousse was placed in refrigerator after stirring with gelatin solution. The samples were stored in a refrigerator for 24 hours.
    Results And Discussion
    In this work, physical, sensorial and rheological properties of chocolate mousse were investigated. Rheological measurements were carried out using a rotational viscometer (Bohlin Model Visco 88, Bohlin Instruments, UK) equipped with a heating circulator (Julabo, Model F12-MCand, Julabo Labortechnik, Germany) and C30 spindle. All the experiments were performed at 25°C±0.2. A pre shearing of 10-15 s at 14.1 s was applied to all samples. Sample flow was measured by registering the shear stress/ shear rate data at an increasing trend from 14.1 to 300 s. To describe the time independent flow behavior, the experimental data (shear stress-shear rate) were fitted by Herschel- Bulkley, Bingham, power law, and Casson models. Sensorial properties were tested at the same optical condition and environmental temperature. Chocolate mousses were evaluated using hedonic analysis procedures by a sensory panel of ten assessors, who had been selected and trained. Sensorial properties were evaluated based on 1 to 9 scores. The gas hold-up was calculated by comparing the density of the aerated chocolate with the gas-free density of solid chocolate. PCA method was used for determination of the relation of sensory attributes and main component.
    Conclusion
    Results showed that chocolate mousse incorporating 2 gr gelatin and 3 gr sodium caseinate had the best sensory properties. According to the R2 (R2>0/99) and RMSE values, it is obvious that the Power-law models can properly describe non-newtonian flow behavior of samples. Behavior index (n) and consistency coefficient (k) were obtained from fitting power-law model. Consistency coefficient was high in the sample containing 3 gr gelatin and 3 gr sodium caseinate. Density values decreased with increase in protein content and decrease in gelatin content. Based on PCA results, total acceptance of samples was severely related to the smoothness, jelly and melting rate attributes.