본 실험에서는 낙농 제품의 국산화를 위한 방안을 모색하고자 다양한 생치즈 및 유청 음료를 개발하여 그 특성을 관찰하였다. 수율은 생치즈에서 22.3%, 유청에서는 77.7%이었다. pH는 생치즈에서 6.46, 변형 생치즈는 첨가된 성분에 따라 $5.90{sim}6.49$로 약간의 차이를 보였고 순수 유청에서는 6.49, 유산균 발효 유청은 $3.97{sim}4.91$, 변형 유청은 $6.07{sim}6.47$로 측정되었다. 적정산도는 생치즈에서 $0.09{sim}0.26%$, 유청 음료는 $0.09{sim}0.36%$이었다. 생치즈의 고형성분, 단백질, 유당 함량은 각각 $25.67{sim}34.18%$, $7.45{sim}9.11%$, $3.61{sim}4.14%$를 나타내었고 유청 음료는 각각 $7.39{sim}7.70%$, $0.88{sim}0.94%$, $4.93{sim}6.17%$를 나타내었다. 유청 음료 100 ml당 젖산 함량은 $0.01{sim}0.38g$으로 유산균 발효 음료에 가장 많았다. 일반 세균군집은 생치즈에서 $0{sim}30/g$, 유청 음료 중에서 $0{sim}80/ml$이었다. 호냉성 세균군집은 생치즈에서 $0{sim}20/g$$이었고, 유청 음료 중에는 $0{sim}60/ml$이었다. 유산균은 유산균 발효 음료에서만 $97{sim}401{ imes}10^8/ml$ 검출되었다. 대장균, 진균은 두 제품 모두 검출되지 않았다. 생치의 관능검사 결과 딸기 생치즈가 가장 양호하였고, 마늘 생치즈가 가장 열등하게 평가되었다. 유청 음료는 순수 유청이 가장 양호하였고, 인삼유청이 가장 열등하게 평가되었는데 이의 개선을 위한 연구가 요망된다.
In order to save foreign currency and to domesticize the dairy products, various fresh cheeses and whey drinks were developed and some physicochemical, microbiological and sensory evaluation were performed. The yield of fresh cheese was 22.3%, while that of whey 77.7%. The pH-values of fresh cheeses were $5.90{sim}6.49$, while those of whey drinks $6.07{sim}6.49$, and fermented whey drinks $3.97{sim}4.91$. The acidities of fresh cheeses were $0.09{sim}0.26%$, while those of whey drinks $0.09{sim}0.36%$. The contents of solid substances, protein and lactose in fresh cheeses were $25.67{sim}34.18%$, $7.45{sim}9.11%$ and $3.61{sim}4.14%$, while those of whey drinks $7.39{sim}7.70%$, $0.88{sim}0.94%$ and $4.93(sim}6.17%$, respectively. The lactic acid contents of whey drinks varied from $0.01{sim}0.38%$, where the content in the fermented sample was the highest. The general colony counts of fresh cheeses were $0{sim}30/g$, while those of whey drinks $0{sim}80/ml$. The psychrotrophs counts of fresh cheeses were $0{sim}20/g$, while those of whey drinks $0{sim}60/ml$. Lactic acid bacterial counts in both products were not detected except for $97{sim}401{ imes}10^8/ml$ in fermented whey drinks. E. coli and fungi were not detected in both products. In sensory evaluation of both products, the strawberry added fresh cheese was the best of fresh cheeses, while the garlic added fresh cheese was the worst. Pure whey drink was the best of whey drinks, while the ginseng added whey drink was the worst.
