کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7599540 | 1492141 | 2014 | 29 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A comparative study of the antioxidant scavenging activity of green tea, black tea and coffee extracts: A kinetic approach
ترجمه فارسی عنوان
بررسی تطبیقی فعالیت آنزیمی ضد چرکین چای سبز، چای سیاه و قهوه: رویکرد جنبشی
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
چکیده انگلیسی
The antioxidant activities of three beverages, coffee, black tea and green tea, along with their major components, were investigated in terms of their reaction with the stable radical 2,2â²-diphenyl-2-picrylhydrazyl (DPPH). We used a kinetic approach in parallel with quantification methods based on a fixed end-point to determine the scavenging efficiency of compounds abundant in these beverages during their reaction with DPPH using a stopped-flow spectrophotometer-based method. Ascorbic acid, (+)-catechin, (â)-epigallocatechin, tannic acid, and caffeic acid were selected as model antioxidants to study in coffee, black tea and green tea. We applied a second-order model to demonstrate similarities in the kinetics behavior of beverages and related compounds. Our findings showed the slopes k2â²((mol/L)-1s-1) and k2maxâ²((mol/L)1s-1) exhibited similar and correlated values; we suggest the variation in k2â² as a function of time is more informative about antioxidant properties than reaction with DPPH alone. We also used IC100 to test the reliability of the relative stoichiometry using a new comparative parameter “n”, which was calculated as: n=c0DPPHIC100 (mol/L (mol/L)â1, (mol/L) ml mgâ1 or mol gâ1).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 150, 1 May 2014, Pages 438-447
Journal: Food Chemistry - Volume 150, 1 May 2014, Pages 438-447
نویسندگان
Jaouad Anissi, Mohammed El Hassouni, Abdelkrim Ouardaoui, Khalid Sendide,