29B-28 |
Optimization of bleaching conditions of roasted sesame oil |
E. CHOE1, I. KIM1, Y. LEE1, and M. Kim2. (1) Department of Food and Nutrition, The Inha University, 253 Yonghyundong, Namku, Incheon, 402-751, South Korea, (2) Food and Nutrition, Inha University, 256 Younghyundong Namgu, Incheon, 402-751, South Korea Roasted sesame oil is famous for its characteristic flavor and high contents of physiologically good components. However, its dark color and low smoke point limit its use in food industry. To make light colored roasted sesame oil with higher smoke point, bleaching conditions of sesame oil were optimized by determining smoke point, colors, free fatty acid and conjugated dienoic acid formation, carbonyl value, fatty acid composition, refractive index, viscosity, and contents of tocopherol, sesamol, sesamin, and sesamolin. Roasted sesame oil was mixed with activated acid clay (0.5, 1.0, and 3.0 %; w/w) at 70, 85, or 100 C for 20 min. The oil was centrifuged at 10,000 rpm and 4 C for 10 min. Bleaching of roasted sesame oil resulted in increase in smoke point and lightness in color. However, it decreased free fatty acid and conjugated dienoic acid contents, carbonyl values, refractive index, and viscosity suggesting that bleaching could improve physico-chemical quality of roasted sesame oil. The more the bleaching clay was used, the better the oil was. Unlike the amount of acid clay, bleaching temperature did not significantly affect the oil quality. Tocopherol, sesamol, sesamin, and sesamolin were remained relatively constant except in the oil bleached with 3% acid clay. They were not significantly different with respect to bleaching temperature. Among conditions carried out, 1% of acid clay and 85 C were thought to be the best bleaching condition to give good quality of roasted sesame oil with better oxidation indicators and higher contents of tocopherol, sesamin, sesamolin and sesamols.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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