FOOD&CHEMISTRY

Fermented properties and polyphenol quantity of fermented milk made with red ginseng extract, Lycium chinense Mill extract, and rice powder

Kwang-Yeon  Kim1   Gereltuya  Renchinkhand1   Woo Jin  Ki1   Jong Woo  Choi2,*   Myoung Soo  Nam1,*   

1Department of Dairy Science, Graduated School, Chungnam National University, Daejeon 34134, Korea
2Center for Research and Development, Choheung Corporation, Ansan 15410, Korea

Abstract

Fermentation characteristics of fermented milk with the addition of Korean traditional medicinal plants, Lycium chinense Mill, red ginseng extract, and rice powder, were investigated. The pH of the control group and the treated groups [rice powder 4%, rice powder 4% + Lycium chinense Mill 2% + red ginseng extract 1% (A), and rice powder 4% + Lycium chinense Mill 5% + red ginseng extract 1% (B)] decreased similarly, declining to 4.6 or less after 12 hours of fermentation. After four hours of fermentation, the number of lactic acid bacteria in the control group was 7.2 × 108 CFU·mL-1 and that of the treated group A was 1.1 × 109 CFU·mL-1, the highest among the experimental groups. After 48 h of fermentation, the viscosity of the control group was 1,066.67 cP, and that of the treated group B was 1,293.34 cP, and the viscosity increased as the additive content increased. As for sugar components, lactose, galactose, and glucose as well as trace amount of fructose were confirmed in the treated groups. At 48 h of fermentation, the organic acid components of oxalic acid, malic acid, an unknown acid, lactic acid, acetic acid, and isobutyric acid in the treated group B were higher than those of the other group. Total phenol and flavonoid quantity increased in proportion to fermentation time and the amount of additives. In the sensory evaluation, the overall preference was lower as the additive was increased. The storage evaluation for 15 days in the control group and the treatment groups was normal in all analysis items.

Figures & Tables

Fig. 1. Changes of the number of lactic acid bacteria in yogurt added Mill. extract, red ginseng extract and rice powder by fermentation for 48 h at 37℃. ○, Control; △, 4% rice powder; □, 2% Mill. extract + 4% rice powder + 1% red ginseng extract; ◇, 5% Mill. extract + 4% rice powder + 1% red ginseng extract. * significant difference in treatment (p < 0.05).