Quality Characteristics of Red Ginseng Yogurt Produced with Probiotic Lactic Acid Bacteria Isolated from Kimchi

Abstract

This study aimed to determine the probiotic properties of lactic acid bacteria (LAB) isolated from kimchi and to develop a probiotic starter culture for yogurt supplemented with red ginseng extract powder (RGE). Two LAB strains were selected by analysis of acid resistance, bile resistance and antioxidant activity, and identified as Lactiplantibacillus plantarum SY46 and Levilactobacillus brevis SY65 by 16S rRNA sequencing. Both strains showed similar or higher auto-aggregation, co-aggregation, antimicrobial activity, and antioxidant activity compared to Lacticaseibacillus rhamnosus GG, a commercial probiotic strain. The yogurt samples, which were supplemented with 5% or 10% RGE and fermented with the mixed culture of SY46 and SY65, exhibited pH values of 4.28-4.46 and titratable acidity of 1.25-1.53%, and their viable cell counts were over 9.0 Log CFU/mL. The antioxidant effects using DPPH radical scavenging and β-carotene bleaching assay were significantly increased with increasing RGE concentrations (p<0.05). Overall, yogurts fermented with 5% or 10% RGE were acceptable in terms of pH, titratable acidity, cell viability and antioxidant effect. These results might provide useful information for the development of ginseng dairy products with probiotic properties.