Panax ginseng marc is produced from fresh ginseng roots during processing and is generally treated as industrial waste. The primary aim of this study was to improve its utilization in the dairy industry as a potential high-value resource. Yogurt was prepared from 11% skim milk powder, 0.1% pectin, 10% sucrose, and ginseng marc ethanol extract (GME, 0.5% and 1.0%) in milk, and was inoculated with a 0.02% yogurt culture (Lactobacillus acidophilus, Bifidobacterium longum, and Streptococcus thermophilus). After fermentation at 40°C for 6-8 h, the physicochemical properties of samples were analyzed by the AOAC, Kjeldahl, and Soxhlet methods. Sensory evaluation was performed based on consumer acceptability scores with a 7-point scale, and antimicrobial effects were measured by the agar plate method. The moisture, crude protein, crude fat, and ash contents of yogurt supplemented with 1% GME were 85.06±0.06%, 4.41±0.01%, 4.30±0.05%, and 0.81±0.03%, respectively, with no significant changes noted from those of yogurt without GME (control), except for an increase in the crude fat content. The sensory scores of color, flavor, texture, overall taste, and overall acceptance of yogurt supplemented with below 1% GME did not differ significantly (p<0.05) to those of the control yogurt. In addition, the growths of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli, and Enterobacter sakazakii were inhibited during fermentation and storage. These results suggest that GME could be used in dairy products as a supplement and in the food industry as an antimicrobial material.
Keywords: Panax ginseng marc; antibacterial effect; sensory evaluation; yogurt.