A new process for soy sauce fermentation by immobilized yeasts.

Abstract

Using bioreactors with yeasts, Zygosaccharomycesrouxii that undergoes ethanol fermentation and produces 2-phenyl ethanol, and Candida versatilis that produces 4-ethyl guaiacol, adsorbedimmobilized on a ceramic carrier, the total time required for production of soy sauce was shortened to 8 days without affecting the product's quality. Recently, in addition to conventional techniques, the use of bioreactors with immobilized enzymes and/or immobilized microorganisms in food industry has been popular. A new process using bioreactors with immobilized cells which was different from the conventional soy sauce fermentation was investigated. Osaki et al.l) reported that the use of bioreactors packed with calcium alginateentrapped yeasts shortened the aging of soy sauce fermentation. Although there would not be any safety problems when calcium alginate gel is used in the food industry, calcium alginate gel is unstable to heat, and therefore can not be sterilized completely by steam. Furthermore, owing to

A Modified Process for Soy Sauce Fermentation by Immobilized yeasts

“…In a previous paper 1 ) we described a soy sauce fermentation process using a two-stage bioreactor with cylindrial filamentous ceramics with fixed yeasts (Zygosaccharomyces rouxii and Candida versatilis). With this process, fermentation time was reduced to 8 days in continuous fermentation for a long period of operation.…”

“…1) The culture media, feed solution for soy sauce fermentation, and composition of seed and main mashes were the same as those described in our previous report. 1) The reactors were made of glass 4.5 cm in diameter and 269 20 cm in .height. The feed solution was pumped in from the conical shaped bottom of the bioreactors.…”