• Journal of Nutrition and Health
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• v.16 no.4
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• pp.281-286
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• 1983

The interactions of phytic acid with protein and minerals has been blamed to decrease the bioavailability of protein and minerals in soybean products. Tempeh, the traditional Infonesian fermented soybean product, was prepared to investigate the changes of phytic acid contents nesian fermented soybean product, was prepared to investigate the changes of phytic acid contents and its interactions with protein and minerals in the fermentation. The acceptability of tempeh were also studied by conducting sersory evaluation. 1) Phytic acid contents of cooked soybeans and of tempch were significantly lower than that of raw soybeans, indicating that cooking and fermentation resulted in the decrease in phytic acid content of soybeans. In tempeh the fraction of phytic acid retained after ultrafiltration was significantly lower than that in raw soybeans. 2) The total protein contents were not significantly different between raw soybeans and tempeh. Phytic acid contents per gram of protein retained ultrafiltration were significantly higher in raw soybeans than in tempeh. This result is interpreted as that raw soybeans contain higher amounts of phytic acid- protein complexes than tempeh. 3) Both of calcium and zinc contents were not significantly different among raw, cooked soybeans and tempeh. However, the retained Ca and Zn fraction after ultrafiltration were significantly lower in tempeh comparing with that in raw soybeans. Lower retention of Ca and Zn after ultrafiltration in tempeh may be the result of lower phytate content of tempeh, thereby less chance of forming mineral- phytate complexes. 4) Tempeh received the sensory evaluation scores between good and fair and the addition of garlic to tempeh significantly improved the odor, general desirability and total score.