Effect of Temperature on the Free Radical Scavenging Capacity of Extracts from Red and White Grape Pomace Peels
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- 作者：José ; A. Larrauri ; Concepció ; n Sá ; nchez-Moreno ; and Fulgencio Saura-Calixto
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：1998
- 出版时间：July 1998
- 年：1998
- 卷：46
- 期：7
- 页码：2694 - 2697
- 全文大小：102K
- 年卷期：v.46,no.7(July 1998)
- ISSN：1520-5118
文摘
Free radical scavenging capacity of the extracts from red and white grape pomace peels (RGPP,WGPP) and as a reference for two commonly used antioxidants (BHA (synthetic) and DL-
-tocopherol(natural) heated at processing temperatures (80, 100, and 120 
C) was evaluated using the 2,2-diphenyl-1-picrylhidrazyl (DPPH
) reagent. Kinetic behavior of the sample extracts did not changewhen they were heated, following a general multiplicative model in which remaining DPPH wasmore affected by temperature than the time needed to reach the steady state. The reduction ofthis property in the sample extracts heated at 120 C as compared to those at 20 C followed anincreasing order: BHA (15.3%) < WGPP (22.9%) < RGPP (28.3%) < DL--tocopherol (69.8%). Colorlosses were also measured by a tristimulus colorimeter HunterLab and two parameters were usedto express the sample extract color: hue angle (tan b*/a*)-1 and a*/b* ratio. The higher red colorlosses in RGPP extracts (12.9 times in hue angle) as compared to the yellow color losses in theWGPP extracts (1.5 times in a*/b* ratio) during heating may explain their differences in the freeradical scavenging capacity.Keywords: Grape pomace; extracts; free radical scavenging; temperature
-tocopherol(natural) heated at processing temperatures (80, 100, and 120 C) was evaluated using the 2,2-diphenyl-1-picrylhidrazyl (DPPH) reagent. Kinetic behavior of the sample extracts did not changewhen they were heated, following a general multiplicative model in which remaining DPPH wasmore affected by temperature than the time needed to reach the steady state. The reduction ofthis property in the sample extracts heated at 120 C as compared to those at 20 C followed anincreasing order: BHA (15.3%) < WGPP (22.9%) < RGPP (28.3%) < DL--tocopherol (69.8%). Colorlosses were also measured by a tristimulus colorimeter HunterLab and two parameters were usedto express the sample extract color: hue angle (tan b*/a*)-1 and a*/b* ratio. The higher red colorlosses in RGPP extracts (12.9 times in hue angle) as compared to the yellow color losses in theWGPP extracts (1.5 times in a*/b* ratio) during heating may explain their differences in the freeradical scavenging capacity.Keywords: Grape pomace; extracts; free radical scavenging; temperature