Effects of Aging of "Kaeshi" on the Quality of "Sobatsuyu", Japanese Noodle Soup

Utilization Techniques of Soy Sauce in Food Processing Part 1

Abstract

"Sobatsuyu" (Japanese noodle soup) is prepared by blending of" Kaeshi" (mixture of soy sauce, sugar and Mirin) and a hot water extract of dried bonito. The quality of "Sobatsuyu" made from "Kaeshi" aged under different conditions in our laboratory was investigated. Flavor of the "Kaeshi" sample (sample A) which was prepared by aging in a opened vessel was superior to the sample prepared in a closed vessel (sample B) by sensory analysis. Evaporation of water and alcohol was observed in the opened system (sample A) during storage, while not in the closed system (sample B). Coloring occurred in sample A during storage but not in sample B. This coloring was considered not to influence sensory improvement, since sensory analysis revealed that "Kaeshi" stored in nitrogenous atmosphere was also as good as that in air. A distinct increase of microorganisms was not observed in both samples A and B. Some volatile components decreased in sample A in contrast to sample B during storage. These experiments suggest that a decrease of certain compounds in physical phenomena such as evaporation plays an important role for improving "Kaeshi" quality during storage.