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The average milk fat content in goat milk was 3.88% on yearly basis. The milk fat content of 3.8% during summer season was lower than 4.2% during winter season. Total solid content increased in proportion to milk fat. When goat milk was stored at 4℃ for 24 hr, short-chain FFA(C4:0~C10:0) and medium- and long-chain FFA(C12:0~C18:1) increased about 106% and 203%, respectively. Induced lipolysis of goat milk by homogenization increased short-chain FFA and medium- and long-chain FFA by 22% and 199%. When goat milk was treated with calf lipase, there was increase of short-chain FFA by 9 times greater than increase of medium- and long-chain FFA by 5.6 times. Treatment with lipases from Candida rugosa and Pseudomonas fluorescens resulted in increase of medium- and long-chain FFA by 34 and 162 times, respectively, which was greater than increase of short-chain FFA by 6 and 14 times, respectively. Lipolysis in goat milk stored at 4℃ for 24 hr was correlated with LPL activity in goat milk(r=0.5635). Off-flavor of goat milk was correlated with LPL activity(r=0.5777). Milk fat content was negatively correlated with LPL activity(r=－0.4627). Palmitic acid content in goat milk was correlated with off-flavor(r=0.7226).

To develop the manufacturing method of ice cream with microbiologically safe and proper sensory quality using irradiation for sensitive consumer, 3 different flavors, which were resistant to their flavors against irradiation, were selected and used for ice cream manufacturing to reduce the irradiation-induced off-flavor problem. The general composition was not different among treatments. Total aerobic bacteria were detected as 2.38, 1.23, 1.38, and 1.15 log CFU/g level in ice cream with control(no flavor added), spearmint, mint, and citrus flavor, respectively. No viable cells were observed by irradiation at 1 kGy except for the control. Sensory evaluation indicated that the irradiated ice cream with spearmint flavor at 1 kGy and citrus flavor at 3 kGy had higher overall acceptability. Therefore, a low dose irradiation (less than 3 kGy) with mint or citrus flavors may enhance the safety of ice cream with proper sensory quality for sensitive consumer.