Physicochemical characteristics and antioxidant capacity in yogurt fortified with red ginseng extract

Abstract

The objective of this study was to investigate characteristics and functionality of yogurt applied red ginseng extract. Yogurts added with red ginseng extract (0.5, 1, 1.5, and 2%) were produced using Lactobacillus acidophilus and Streptococcus thermophilus and stored at refrigerated temperature. During fermentation, pH was decreased whereas titratable aicidity and viable cell counts of L. acidophilus and S. thermophilus were increased. The composition of yogurt samples was measured on day 1, an increase of red ginseng extract content in yogurt resulted in an increase in lactose, protein, total solids, and ash content, whereas fat and moisture content decreased. The pH value and cell counts of L. acidophilus and S. thermophilus were declined, however titratable acidity was increased during storage period. The antioxidant capacity was measured as diverse methods. During refrigerated storage time, the value of antioxidant effect was decreased, however, yogurt fortified with red ginseng extract had higher capacity than plain yogurt. The antioxidant effect was improved in proportion to concentration of red ginseng extract. These data suggests that red ginseng extract could affect to reduce fermentation time of yogurt and enhance antioxidant capacity.