Isolation and Caracterization of Microorganisms for Indonesian Low-Salt Soy Sauce Production

Abstract

Soy sauce is a fermented soybean product that is consumed broadly as a food condiment in Asian cuisine. Indonesian traditional soy sauce is produced through high salinity brine fermentation with NaCl 12-26%. Salt is a fundamental component required in fermentation since it determines the organoleptic characteristics affecting flavor and texture, as well as microbial properties. However, the prevalent issue over the overconsumption of salt has been constantly elevating and causing detrimental threat as a major risk factor for cardiovascular disease. A recent method to reduce salt content and maintain the rich flavor of soy sauce was achieved by adding indigenous yeasts, discovered in Korean traditional soy sauce fermentation to process low-salt soy sauce, which stimulates the interest in conducting further isolation of potential microorganisms for low-salt soy sauce production. Isolation and characterization of unidentified microorganisms from traditional soy sauce is a prerequisite study for the development of low-salt soy sauce. In this study, an Indonesian soy sauce Bungkil (Koji) and Baceman (Moromi) sample from Majalengka was collected as a potential source of a variety of microorganisms. Characterization of the colony and microscopic morphology, biochemical analysis as well as microbial DNA detection by PCR and gel electrophoresis assay of the microbial isolates were investigated, as a preliminary study for potential use in low-salt soy sauce production.