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M.-Y. BAIK1, B.-Y. Kim2, H.-J. Koo3, S.-H. Park3, and J.-S. Jo3. (1) Department of Food Science and Technology, KyungHee University, Seochun 1, Yongin, 449-701, South Korea, (2) Dept. of Food Science & Technology, Kyung Hee University, Seochun 1, Yongin, 449-701, South Korea, (3) Dept. of Food Science & Technology, Kyung Hee Univ., School of Life Resource Science, Seochun 1, Yongin, 449-701, South Korea Preservation and circulation of fresh ginseng in natural condition is difficult due to its high moisture. To increase the shelf-stability, fresh ginseng is normally cooked and dehydrated to make red ginseng. It is generally recognized that the occurrence of inner white, the main defect of red ginseng, is highly dependent on growing and processing conditions as well as the amount and physicochemical properties of starch in fresh ginseng. Physicochemical properties of three kinds of 6-year-old Korean ginseng starches (best or 1st, medium or 2nd, and worst or 3rd grade) were investigated to provide basic and scientific information for the effect of starch on quality of red ginseng. Three grades of ginseng starches were isolated and their physicochemical properties were determined using SEM, RVA, DSC and X-ray diffractometer. The ginseng starch granule showed typical B-type crystal with spherical shape and its size was 2-8 micrometer. The 3rd grade ginseng starch showed the highest relative crystallinity followed by 2nd and 1st grade but they are not significantly different at 95% confidence level. The 1st and 3rd grade ginseng starches showed typical biphasic DSC endotherm while 2nd grade ginseng starch revealed monophasic DSC endotherm with relatively narrow transition temperature. Although Avrami exponents (n) of all ginseng starches were close to 1.0 (i.e., retrogradation of all ginseng starches at a single temperature have an instantaneous nucleation followed by rod like growth of crystals), 1st and 3rd grade ginseng starches showed higher degree of retrogradation and faster retrogradation rate than 2nd grade ginseng starch. This indicates that 2nd grade ginseng starch has different physicochemical characteristics compare to 1st and 3rd grade ginseng starches, which may influence the occurrence of inner white, the main defect of red ginseng. This work provides the basic information of physicochemical characteristics of various 6-year-old Korean ginseng starches.
Session 93, Carbohydrate: General
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