Isolation and Analysis of Molds from Soy Sauce Koji in Thailand

Abstract

Five different isolates of Aspergillus and one of Mucor were compared with a Japanese commercial strain of Aspergillus oryzae for proteolytic activity on wheat bran substrate. One isolate of Aspergillus with superior protease production, identified as Aspergillus flavus var. columnaris , showed no detectable aflatoxin production on glutinous rice or soybean substrate. Preliminary tests using this fungus as a koji mold in a traditionally operated factory resulted in a soy sauce superior in quality to that usually produced.

Problematic Occurrence of Tyrosine Crystals in the Thai Soybean Paste Tao Chieo

“…Since the factory owners had not noticed tyrosine crystals in their tao chieo before the use of controlled Aspergillus inoculum, we assumed that the controlled inoculum had somehow caused their formation. Two immediately apparent possible reasons for this were (i) that the fungus had produced tyrosine as an excess anabolic product during its growth in the koji, or (ii) that the increased protease activity in the controlled inoculum koji (1) had released tyrosine from the substrate in sufficient quantity to exceed its solubility in water. FIG.…”

Diversity of <i>Aspergillus oryzae</i> genotypes (RFLP) isolated from traditional soy sauce production within Malaysia and Southeast Asia

“…During the koji stage of fermentation, mold enzymes bring about the saccharifi cation of starch and decomposition of protein in the raw materials that support yeast and bacterial growth essential to the main brine fermentation (Yong and Wood 1974;Yokotsuka 1986). Soy sauce manufacture in Southeast Asia is carried out using a traditional method similar to that practiced in southern China (Bhumiratana et al 1980;Steinkraus 1983;Lotong 1985;Mongkolwai et al 1997). Whole steam-cooked soybeans are mixed with wheat fl our and spread (3-5 cm thick) onto bamboo trays that are incubated (5-7 days) on open shelves in rooms without temperature or moisture controls.…”

Occurrence of toxicity among protease, amylase, and color mutants of a nontoxic soy sauce koji mold

“…It was deposited with the American Type Culture Collection as ATCC 44310 under that name. We have used this name since 1980 (2). However, the strain could also be named A. oiyzae var.…”