Abstract
For lactic acid fermentation of chestnut broth,10 strains of bacteria were isolated from human feces and commercial yogurt,6 of which were identified to be Bifidobacterium and the rest isolated from Acidities of the chestnut broths fermented by these strains were lower than yogurt, but more than two times higher than yogurts made from seeds or vegetables including soy milk. To stimulate acidity of the fermented broths, addition of yeast extract and tryptone peptone were the most effective at the concentration of 0.2 and 0.4%, respectively, while glucose addition above 0.5% up to 8% did not increased the acid production except a few strains of Lactoba- Cillus. Among the tested fruits and vegetables, carrot juice supplementation was the most effective in acid produc- tion by most of the tested strains. Saccharification of chestnut broth by hydrolyzing process greatly increased the acid production at 25% of cooked chestnut. However, compared to the results from the 8% of unhydrolyzed chest- nut, the net increase in acid production by hydrolysis was not much stimulative.
분변과 요구르트에서 10주의 젖산균을 분리하여 이중 6주는 Bifidobactria로 4주는 Lactobacilli로 동정하였다. 이들은 이용하여 8% 증숙밤용액을 발효시켰을 때 발효액의 산도는 요구르트보다는 낮았으나 두유를 비롯한 식물성 요구르트보다는 2배이상 높았다. 산도를 증가시키기 위해 Yeast extract 와 tryptone peptone를 첨가할 때 0.2%와 0.4%의농도에서 가장 높았다. 포도당을 0.5-0.8% 범위의 첨가하였을 때 lactobacilli에 의한 발효액에서는 산생성이 촉진되었으나. bifidobacteria 에서는 그렇지 않았다. 시험된 과일과 채소즙 중에서는 당근즙의 첨가가 가장 큰 촉진 효과를 나타내었다. 25% 밤용액에서는 고지추출액에 의한 가수분해는 젖산생성을 크게 촉진하였으나 가수분해하지 않은 8% 밤용액에서는 젖산생성량과 비교하였을 때 산생성 순증가량은 그다지 크지 않았다.