44E-2 |
Shelf-life stability of isoflavones in soy meal and soy protein concentrate |
L. XIE1, N. S. Hettiarachchy1, Z. Y. Ju1, P. G. Crandall1, and R. McNew2. (1) Dept. of Food Science, Univ. of Arkansas, Fayetteville, AR 72704, (2) Dept. of Agricultural Statistics, Univ. of Arkansas The presence of isoflavones is responsible for the recent upsurge in interest in soy and soy foods. In various experimental models, isoflavones have been shown to inhibit the growth of cancer cells, lower blood cholesterol, and inhibit bone resorption. The realization of health benefits from adding soy products to human diet may depend on the stability of isoflavones during storage and processing as well as the specific profile of the isoflavone derivatives in the finished products. The objectives of this study were to: (1) Screen 23 soybean varieties for their isoflavone contents and prepare soybean meal (SM) and soy protein concentrate (SPC) from a variety which had the highest amount of isoflaovnes; (2) Investigate the stability of isoflavones in SM and SPC that have been treated with /without b-glucosidase enzyme. A 2x3x3 factorial design was used in this study. SM, SPC & enzyme treated SPC were stored at 4°C/25°C/37°C and at 50%/65%/85% relative humidity (RH). The stability of isoflavones were quantified by HPLC at regular intervals. The isoflavone contents in soybean, SM, SPC, &enzyme treated SPC (to convert glycosides to aglycones) were 4.566 mg/g, 4.452mg/g, 2.914 mg/g, 3.736 mg/g, respectively. At 3 month storage, no isoflavones losses were observed under all conditions of storage, except the products stored at higher RH (85%). These results show that SM, SPC & enzyme treated SPC can be stored for at least 3 months without any appreciable losses in isoflavones.
Session 44E, Nutraceuticals & Functional Foods
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