Abstract
In a Bangkok soy sauce factory that had recently converted to controlled inoculum and incubation for the koji stage of fermentation, a problem arose with unsightly white particles in the soybean paste condiment called tao chieo. This problem had not arisen during the previous history of the factory where the koji stage of the fermentation was uncontrolled. Microscopic examination of the particles showed that they were crystalline. Physical separation of the crystals followed by solvent extraction, recrystallization, chemical characterization, and spectroscopy showed that they consisted of tyrosine. Tao chieo prepared by using low- or high-protease strains of Aspergillus sp. indicated that the tyrosine crystals resulted from mold proteolysis of the soybean substrate. Addition of polyethylene glycol at the beginning of the moromi fermentation reduced the severity of crystal formation.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bhumiratana A., Flegel T. W., Glinsukon T., Somporan W. Isolation and analysis of molds from soy sauce koji in Thailand. Appl Environ Microbiol. 1980 Feb;39(2):430–435. doi: 10.1128/aem.39.2.430-435.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]