포도과즙(果汁), 산유(酸乳), 설탕을 주원료로하여 포도과즙(果汁) 혼합음료를 제조하고 동(同) 음료의 보존성을 검토하여 다음과 같은 결과를 얻었다. 1) 포도과즙(果汁) 산유(酸乳) 혼합음료는 과즙(果汁)중의 colloid와 유(乳)단백질의 결합에 의하여 응집 침전물을 형성하며 가열살균에 의하여 침전물의 형성이 촉진된다. 2) 원료과즙(果汁)의 pectin함량은 제품의 안전성에 직접적으로 관계되며 과즙(果汁)중의 pectin함량은 제품의 안전성에 직접적으로 관계되며 과즙(果汁)중의 pectin함량이 2.5mg% 이하일 때 과즙 $10{sim}20%$ 혼합시에 있어서도 응집 침전물의 형성을 방지할 수 있다. 3) pectin분해효소로써 처리한 투명과즙(果汁)을 사용하여 제조한 혼합음료는 $85^{circ}C$ 20분간의 가열살균으로 응집 침전물이 형성되지 않으면 장기간의 저장이 가능하다.
The acid milk containing grape juice was prepared from natural grape juice, acid milk and sugar as raw materials, and the stability of the drink was studied. The following results were obtained. 1. The milk mixed with natural grape juice formed coagulated precipitate by coupling of the colloidal materials in the juice with the milk protein and the formation of precipitate was accelerated by pasteurization. 2. The pectin in natural grape juice was affected on the stability of the product, and the stability increased with decrease in the content of pectin. When the content of pectin in natural grape juice was lower than 2.5mg%, the precipitate was not formed in the drink containing 10 to 20% of the juice. 3. The acid milk drink containing the natural grape juice treated with pectinase, not formed precipitate by pasteurization at $85^{circ}C$, for 20 minutes and can be preserved for long term.
