우유(牛乳)의 이용도(利用度)를 다양화하기 위하여 새로운 발효유(醱酵乳)를 개발(開發)할 목적(目的)으로 몇가지 기초실험(基礎實驗)을 실시(實施)하고 알코올함량 및 산도(酸度)를 달리하여 8종(種)의 알코올발효유(醱酵乳)를 제조(製造)하고 관태검사(官態檢査)를 실시(實施)하였던 바 그 결과를 요약하면 다음과 같다. 1. 유산균(乳酸菌)은 4종(種)을 분리(分離)했고 그중 Y-2균주(菌株)가 산생성도(酸生成度)가 우수했고 모든 균주(菌株)는 우유배지보다 합성배지에서 산 생성도가 높았다. 2. 우유배지(牛乳培地)에 Y-2균주(菌株)를 접종(接種)하고 $30^{circ}C$ 24시간(時間) 배양(培養)하면 pH는 6.2에서 5.2로 하강되며 배양중(培養中) Amino-N의 함량은 증감하였다. 3. K. fragilis 균주(菌株)를 우유배지에 접종(接種)하고 $30^{circ}C$ 7일간(日間) 배양(培養)하면 pH는 6.2에서 5.2로 하강되며 Amino-N의 함량은 $0.12{sim}0.27mg/ml$의 분포(分布)를 나타냈다. K. fragilis균주는 E-2, E-4 균주에 비해 알코올생성도(生成度)가 높았으며 각 균주(菌株)의 알코올생성도(生成度)는 우유배지(牛乳培地)와 합성배지(合成培地)에서 별 차이가 없었다. 4. 효모(酵母)를 접종배양(接種培養) 후 유산균(乳酸菌)을 접종(接種)하면 유산균(乳酸菌)의 증식(增殖) 및 산생성도(酸生成度)는 억제된다. 5. 효모와 유산균(乳酸菌)을 동시에 접종배양(接種培養)하면 일단 유산균의 산생성(酸生成)이 완료된후 알코올 생성(生成)이 급격히 증가되었다. 6. 관능검사를 실시한 결과 알코올 1% 산(酸) 0.8%의 제품(製品)이 가장 기호도가 좋았다. 7. 일반분석(一般分析) 결과 최종제품(最終製品)의 성분(成分)은 회분, 단백질, 수분함량에서 우유쿠머스와 비슷하였다.
In order to develope a new kind of fermented milk, basic studies on several lactic acid bacteria and yeasts were conducted, 8 kinds of alcohol fermented milk were manufactured and sensory evaluation was undertaken. The results obtained are summarized as follows: 1. Four kinds of lactic acid bacteria were isolated, among which Y-2 strain was strongest in acid productivity and it was elucidated that acid productivity of all strains was stornger in synthetic medium than in milk medium. 2. The pH in milk medium inoculated with Y-2 strain and incubated at $30^{circ}C$ for 24 hours was dropped from 5.8 to 3.8 and fluctuation in amino nitrogen content was found during incubation. 3. The pH in milk medium inoculated with K. fragilis and incubated at $30^{circ}C$ for 7 days was dropped from 6.2 to 5.2 and amino nitrogen content was in the range of $0.12{sim}0.27mg/ml$. Alcohol productivity of K. fragilis was stronger than E-2 and E-4 strain but no difference in alcohol productivity was found between milk medium and synthetic medium. 4. The repression in growth and acid productivity of lactic acid bacteria was recongnized if inoculated after inoculating yeast firstly. 5. Alcohol productivity was increased rapidly at the end of acid production of lactic acid bacteria if lactic acid bacteria if lactic acid bacteria and yeast were inoculated simultaneously. 6. Sensory evaluation showed that the product that alcohol content and acidity were 1% and 0.8% respectively had the best palatability(p<0.01). 7. Chemical composition of final product was similar to that of milk koumiss in ash, protein and moisture content.
