QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wang, H. L. Articles by Hesseltine, C. W. Search for Related Content PubMed PubMed Citation Articles by Wang, H. L. Articles by Hesseltine, C. W.

Free Fatty Acids Identified as Antitryptic Factor in Soybeans Fermented by Rhizopus oligosporus¹

Northern Regional Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604

The trypsin-inhibitory activity observed in cooked soybeans fermented by Rhizopus oligosporus (fungus used in tempeh fermentation) has been examined. The active compounds have now been isolated by ethanol extraction and thin-layer chromatography and have been identified as free fatty acids by infrared spectroscopy and gasliquid chromatography. Oleic, linoleic, and linolenic acids are primarily responsible for the increased trypsin-inhibiting activity of cooked soybeans after fermentaton. The free fatty acids are liberated from oil in the soybeans by fungal lipase, and they differ from other reported soybean trypsin inhibitors that are protein in nature. Free fatty acids have been previously reported to inhibit various enzymes, such as glycolytic, glyconeogenic, lipogenic, and also proteolytic. Their effect appears to be a nonspecific type of inhibition. Further studies are required to determine their physiological relevance, if any.

KEY WORDS: • fermented soybean • free fatty acid • Rhizopus oligosporus • tempeh • trypsin • trypsin-inhibiting activity

¹ Presented at the Federation of American Societies for Experimental Biology Meeting, Atlantic City, New Jersey, April 13–18, 1975.

Manuscript received 31 March 1975.