밤 Yogurt 의 제조와 특성 I. 밤 Yogurt 의 이화학적 및 미생물학적 성질 = The Manufacture and Characteristics of Chestnut Yogurt I. The Physicochemical and Microbiological Propertles of Chestnut Yogurt

다국어 초록 (Multilingual Abstract)

Physicochemical and microbiological properties of raw and dried chestnut yogurt manufactured by addition of raw and dried chestnut with levels of 1(T₁), 2(T₂), 3(T₃) and 4%(T₄) in skimmilk substrate were investigated during fermentation and storage period. Raw and dried chestnut yogurts were fermented with the mixed cultures of YC-380 and ABT-4, respectively. Titratable acidity and pH values of all treatments were increased and decreased significantly (p$lt;0.05) during fermentation period, respectively, and increased and decreased slightly during the storage period, respectively. Viscosity of raw and dried chestnut yogurt increased rapidly in order of T₄, T₃, T₂ and T₁ during fermentation period. The counts of viable cells of lactic acid bacteria in all treatments were rapidly and slightly increased during fermentation and storage periods, respectively. There were increased in order of all treatments fermented with YC-380 and ABT-4 in acid production and viscosity, while in order of ABT-A and YC-380 in counts of viable cells of lactic acid bacteria of all treatments. The counts of E. coli were not found in raw and dried chestnut yogurt for 12 days of storage after fermentation, respectively. As results the evaluation of physicochemical and microbiological properties of raw chestnut yogurt were better than those of dried chestnut yogurt and T₁ showed slightly high compared to those of control in all treatments. Based on the results of this experiment the optimum level of addition of raw and dried chestnut were 1%(w/v) for acid production, viscosity and the counts of viable cells of lactic acid bacteria.