Kim H Y, Kim S H, Choi M J, Min S G, Kwak H S
Department of Food Science and Technology, Sejong University, Seoul 143-747, Korea.
J Dairy Sci. 2008 Nov;91(11):4176-82. doi: 10.3168/jds.2007-0883.
This study was carried out to investigate the effect of high pressure-low temperature (HPLT) treatment on physicochemical properties and nutrients in milk. The milk was treated at 200 MPa and -4 degrees C for 10, 20, and 30 min. Protease and lipase activities of HPLT-treated milk were highly inactivated compared with that of raw milk. Among time treatments, the 30-min treatment showed the lowest activities compared with others. Absorbance of thiobarbituric acid increased with time in HLPT-treated milks; however, no difference was observed between the raw milk and milk treated for 10 min. The concentrations of short-chain fatty acids except C(4) in HPLT-treated milks increased with time. The total free amino acids in HPLT-treated milks were greater than that of the raw milk for the 30-min treatment. L-Ascorbic acid, niacin, and riboflavin in HPLT-treated milks were significantly lower compared with concentrations in raw milk. For color, the L-value of HPLT-treated milks was significantly lower than that of the raw milk; however, there was no difference in the a-value for 10 min and in the b-value at 20 min between the raw milk and the HPLT-treated milks.
本研究旨在探讨高压低温（HPLT）处理对牛奶理化性质和营养成分的影响。将牛奶在200兆帕和零下4摄氏度下处理10、20和30分钟。与原料奶相比，HPLT处理奶的蛋白酶和脂肪酶活性被高度灭活。在不同时间处理中，30分钟处理组的活性与其他组相比最低。在HPLT处理的牛奶中，硫代巴比妥酸的吸光度随时间增加；然而，原料奶与处理10分钟的牛奶之间未观察到差异。HPLT处理奶中除C(4)外的短链脂肪酸浓度随时间增加。对于30分钟的处理，HPLT处理奶中的总游离氨基酸含量高于原料奶。与原料奶中的浓度相比，HPLT处理奶中的L-抗坏血酸、烟酸和核黄素含量显著降低。在颜色方面，HPLT处理奶的L值显著低于原料奶；然而，原料奶与HPLT处理奶在处理10分钟时的a值以及处理20分钟时的b值没有差异。
