67D-13 |
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J. LEE, J. Chung, and E. Choe. Dept. of Food & Nutrition, Inha Univ., 253 Younghyundong Namgu, Incheon, 402-751, South Korea Soybean oil and sesame oil contain tocopherols and lignans. Blending of these oils can provide antioxidants such as tocopherols and lignans to the oil, but the antioxidants may be decomposed during heating. Heat susceptibility of antioxidants may depend on kinds of antioxidants and co-presence of other antioxidants. Antioxidants changes in the oil mixture at high temperature have not been reported. This study determined changes in tocopherols and lignans in soybean oil and sesame oil mixture during heating. Lignan and tocopherol contents in the oil were determined by high performance liquid chromatography. Volume ratios of sesame oil and soybean oil in the oil mixture were 0:100, 10:90, 20:80, 30:70, and 40:60. Oil mixtures in duplicate were continuously heated at 160oC for 25 h. Soybean oil contained tocopherols (113.14 ppm), and sesame oil contained lignans (117.93 ppm) and tocopherols (737.59 ppm). Lignans in the oil mixture consisted of sesamin, sesamolin, and sesamol in a decreasing order. Sesamin contents were relatively constant during heating and the stability was higher in the oil containing more soybean oil. Sesamol contents tended to increase after initial slight decrease regardless of the concentration of soybean oil in the oil mixture. Sesamolin contents decreased with heating time and soybean oil slowed down its decomposition. d-Tocopherol contents was the highest followed by g- and a- tocopherol in the oil mixture. Tocopherol contents decreased with heating time. d-Tocopherol was the most stable during heating. Tocopherol stability during heating was higher in the oil containing sesame oil. However, tocopherols in the oil containing 30% or 40% sesame oil were degraded a little faster than in the oil with 10 or 20% sesame oil. Theses results clearly showed that stability of tocopherols and lignans during heating were improved by blending of the soybean oil and sesame oil.
Session 67D, Food Chemistry: Lipid and carbohydrate chemistry
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