67D-10 |
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K.-T. Lee, Department of Food Science and Technology, Chungnam National University, 220 Gung-Dong, Yusung-Gu, Taejon, 305-764, South Korea, J.-H. LEE, Department of Food and Nutrition, Chungnam National University, 220 Gung-Dong, Yusung-Gu, Taejon, 305-764, South Korea, and M. R. Kim, Department of Food Science & Nutrition, Chungnam National University, Taejon, 305-764, South Korea. Vegetable oil containing conjugated linoleic acid (CLA) could be beneficial to human since CLA was known to have physiological benefits. Structured lipids (SLs) would be one of the possible means to increase CLA content as triacylglycerol form in foods. SLs can be reconstructed from any lipid, changing fatty acid composition and/or their positional distribution in triacylglycerol molecules by enzymatic or chemical processes. Therefore, CLA (in the free fatty acid form) can be incorporated into triacylglycerol molecules (such as SLs) to provide individuals with physiological benefits Oxidative status of SL was investigated with rosemary extracts used as a natural antioxidant. Also, amounts of tocopherol and color changes in SL were determined. Moreover, volatiles and flavor characteristics analyzed by SPME along with GC-MS and electronic nose were studied. Structured lipid (SL) of soybean oil with CLA was produced through a lipase-catalyzed acidolysis. After isolation, analysis by HPLC, GC, electronic nose, and GC-MS was conducted. 24.4 mol% CLA isomers were incorporated in SL-soybean oil after the 24h reaction. The removal of tocopherols (73~84% loss from original soybean oil) and change of color (more yellowish) in SL-soybean oil were removed. The oxidative stability of SL-soybean oil was lower than that of soybean oil showing higher peroxide values, ¥ñ-anisidine values, and 2-thiobarbituric acid-reactive substances during 20-day study. However rosemary extract, an antioxidant with a different amount (100 to 300 ppm) reduced the oxidative deterioration in SL-soybean oil as well as soybean oil. Electronic nose with metal-oxide semiconducting sensor and GC/MS along with solid-phase microextraction provided the different volatile characteristics between SL-soybean oil and original soybean oil. After SL production, decreased oxidative stability in SLs was observed on account of removal or oxidation of tocopherols that are naturally existed as antioxidant in vegetable oils. Therefore, additional antioxidants should be added into SLs to prevent an oxidation. Even though rosemary extracts showed successful antioxidant activity in SLs, it could have an influence on color and/or flavor changes. The processes in SL production lead to changes in flavor features.
Session 67D, Food Chemistry: Lipid and carbohydrate chemistry
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