Huei-Ju Wang, P. Murphy
Aug 15, 1996
Citations
16
Influential Citations
373
Citations
Quality indicators
Journal
Journal of Agricultural and Food Chemistry
Abstract
The effects of processing techniques on the distribution of isoflavones were investigated by manufacturing tempeh, soymilk, tofu, and protein isolate. The manufacturing steps causing significant losses (p < 0.05) of isoflavones were as follows: soaking (12%) and heat processing (49%) in tempeh production; coagulation (44%) in tofu processing; and alkaline extraction (53%) in soy protein isolate production. In the production of tempeh, soymilk, and tofu, malonyldaidzin and malonylgenistin decreased after soaking and cooking. Concomitantly, acetyldaidzin and acetylgenistin were generated during heat processing. After fermentation, daidzein and genistein concentrations increased in tempeh, apparently as a result of fungal enzymatic hydrolysis. In protein isolate processing, alkaline extraction caused the generation of daidzein and genistein, probably through alkaline hydrolysis. Keywords: Isoflavones; mass balance; soy protein isolate; tempeh; soymilk; tofu