오미자 (Schizandra chinensis) 물 추출액이 Yoghurt Starter의 증식에 미치는 영향

The effect of water extract of Schizandra chinensis on the growth of yoghurt starter was investigated in order to manufacture the drink type yoghurt added with water extract of Schizandra chinensis. It was the most desirable extraction conditions for Schizandra chinensis to soak in 50 times of water for 15 hours at 20℃. The water extract of Schizandra chinensis showed pH 3.07, 2.39% acidity, 1.10% total sugars, and 0.15 optical density for color. The water extract of Schizandra chinensis was added to MRS broth medium from 0.1% to 1.0% and the medium was fermented by 4 types of lactic acid bacteria such as Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus bulgaricus,and Streptococcus thermophilus. The addition of water extract of Schizandra chinensis inhibited the growth of the lactic acid bacteria. The maximum addition amounts of water extract of Schizandra chinensis was 0.9% for Lac. acidophilus, 0.8% for Lac. casei, 0.2% for Lac. bulgaricus and 0.1% for Str. thermophllus in order to maintain the propagation of the lactic acid bacteria. When the drink type yoghurts added with 0.4%, 0.6%, 0.8% and 1.0% water extract of Schizandra chinensis were kept at 4℃ for 15 days, it was showed that the number of lactic acid bacteria was not significantly changed during the storage. The viable cell counts of the drink type yoghurts by addition of 0.4~1.0% of water extract of Schizandra chinensis were 1.13×10^(9)~2.29×10^(9) CFU/mL, and these bacterial counts were still more than the legal standard(1.0×10^(8) CFU/mL) even at 15 days of storage.