Microbial Studies on Shelf Life of "Asazuke"

Studies on the Quality and Behavior of Microorganisms of Pickles. Part I

Abstract

Investigating the relationship between shelf life of "Asazuke" and storage temperature, it seemed reasonable that the shelf life should be determined by the increase of turbidity of the liquid in "Asazuke". The shelf life of "Asazuke" was less than one day at 20°C and 30°C, 3 days at 10°C, 5 days at 7°C and 6 days at 5°C. Though the Gram-negative organisms were predominant among the microorganisms on the early stage, they were killed and decreased by the accumulation of lactic acid produced by the lactic acid bacteria (Leuconostoc mesenteroides) during storage. Thus, lactic acid bacteria were predominant at the subsequent preservation time. Furthermore the change of bacterial flora of Garm-negative organisms was investigated to obtain the results that the genera of Flavobacterium, Pseudomonas and Enterobacter were killed and decreased in this order during storage, depending on their tolerance against salt and lactic acid, namely Enterobacter <Pseudomonas> Flavobacterium.