Gamma-aminobutyric acid (GABA) is a functional component with physiological activity that helps to protect the liver from blood pressure reduction and alcohol damage, and is known to be widely distributed in various vegetables and fruits. In this study, a fermented rice syrup with enhanced GABA content was developed. The improved syrup was prepared by adding monosodium glutamate (MSG) to saccharified rice and using a complex of three types of lactic acid bacteria (Lactobacillus brevis, Lactobacillus plantarum, Leuconostoc mesenteroides ) with excellent GABA production ability. The physicochemical changes of the fermented rice syrup were measured, and the final pH of the product was 4.7 with a total water-soluble solid content of 22.1 °Brix. Of the dissolved solids, glucose (39.6 mg/mL) and maltose (12.7 mg/mL) were the main components, and it was confirmed that all MSG was converted to GABA. From the experiment, it was established that the rice syrup obtained from secondary fermentation of saccharified rice is suitable as a beverage base. The fermented saccharified rice syrup was differentiated from conventional rice fermented products which typically use yeast and acetic acid bacteria in the production process. The enhanced fermented rice syrup produced in this study was made using lactic acid bacteria in the fermentation and saccharified rice.

In this study, thirty-eight lactic acid bacteria (LAB) strains were isolated from Kimchi (Korean traditional fermented food) and screened for probiotic characterization in a series of in vitro tests, including resistance to low pH, tolerance to bile salts, hydrophobicity, antibiotic resistance and antioxidant activity. Firstly, twenty-two strains displayed survival in acid and bile passage conditions. Secondly, the strains KCCP 11349 and KCCP 11356 were observed to have high cell surface hydrophobicity with 63.9 and 98.8 %, respectively. Functionality of these potential probiotic isolates was supported by their antioxidant activity. Altogether, the strain KCCP 11349 showed characteristics similar to or even better than reference strain Lactobacillus rhamnosus GG. Finally, 16S rRNA gene sequencing was conducted to identify potential probiotic strains and KCCP 11349 was identified as Lactobacillus plantarum subsp. plantarum.