Changes in quality characteristics during storage of Korean soy sauce added with onion juice according to heat sterilization conditions

Abstract

The objective of this study was to integrate onion juice into traditional Korean soy sauce and to evaluate the sterilization conditions necessary for commercialization. As the sterilization temperature increased, pH decreased and titratable acidity increased. A reduction in °Brix was observed post-sterilization, from 37.37 °Brix in untreated soy sauce to 36.67-36.77 °Brix. In terms of chromaticity, the L value declined over the storage period while the a and b values increased. The quercetin component exhibited light sensitivity, with no significant difference observed in the sample on the 60th day. Neither Bacillus cereus nor Clostridium perfringens were detected, and the total bacterial count was comparable to that of commercially available soy sauce. This indicates that samples sterilized at 85°C for 30 minutes fall within a safe quality range. Sensory evaluation revealed that samples sterilized at 85°C for 30 minutes exhibited consistently high ratings.