Study on the Preservation of "TAKUANZUKE" in a Sealed Polyethylene Bag

Part I. Isolation of microorganisms and their properties

Abstract

Six species of yeasts and one species of bacteria were isolated from "TAKUANZUKE" (pickled raddish in the mash of rice bran and salt) in a polyethylene film bag in which fermentation was observed. One of the yeasts was identified as Hansenula anomala, two as Torulopsis sake and remaining three also belonged to Torulopsis group. The bacteria seemed to be lactic acid bacteria. Hansenula anomala and Torulopsis sake were not able to grow in 18% brine and the bacteria in 17% brine. Heat treatment was effective to prevent growth of the yeasts at 55°C for 30min., 60°C for 20min., 65°C for 10min. and bacteria at 50-55°C for 20min., 60°C for 10min. Sorbic acid was also effective to prevent growth of these yeasts and bacteria depending upon pH value and NaCl concentration of the growth media.