Enhancement of preservation characteristics of Meju, an intermediate material for Korean legume-based fermented soy sauce, Kanjang, by irradiation

Abstract

Meju, an intermediate product for making Korean traditional soy sauce, Kanjang, was prepared and irradiated at 0, 5, 10 and 20 kGy and then stored at 25degreesC for 12 months (mo). Mould and Lactobacillus spp. were nearly eliminated by gamma irradiation with a dose of 5-10 kGy, and the Bacillus spp. was decreased by 4 decimal reduction with a dose of 10 kGy. Changes of protease activity, NH3-nitrogen, NH2-nitrogen, pH and color in the gamma-irradiated Meju were stable compared to non-irradiated control. Sensory evaluation after 12-mo storage showed that soy sauce made from the Meju irradiated with 10 and 20 kGy was acceptable and scored as same as the freshly made one. Therefore, it was considered that the Meju can be stored up to 12mo by treating with gamma irradiation without any adverse quality change to make soy sauce. (C) 2002 Elsevier Science Ltd. All rights reserved.