季节对内蒙古地区荷斯坦牛乳中脂肪酸含量的影响

Effect of Season on Fatty Acid Content of Holstein Cow Milk in Inner Mongolia

为评价季节对荷斯坦牛乳中脂肪酸成分含量的影响,采集中国内蒙古地区10个大型商业牧场包含春夏秋冬4个季节的牛乳,运用气相色谱法对牛乳中脂肪酸含量进行分析。结果表明:1)内蒙古地区荷斯坦牛乳中主体脂肪酸为棕榈酸、油酸、硬脂酸、肉豆蔻酸和亚油酸,并未因地理位置、奶牛品种、饲料及加工方式等因素发生变化;2)牛乳中饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸在总脂肪酸中的比例稳定,短链脂肪酸、中链脂肪酸和长链脂肪酸在总脂肪酸中的比例也很稳定,受地理位置影响不明显;3)牛乳中主体脂肪酸均呈现出相同的季节差异特点,即春季含量较高,夏季和秋季含量较低;4)饱和脂肪酸和多不饱和脂肪酸含量在夏季与其他季节差异显著(P<0.05),夏季含量最低;单不饱和脂肪酸含量在夏季与春季差异显著(P<0.05),夏季含量最低;5)对于乳脂风味影响较大的短链脂肪酸和中链脂肪酸而言,其含量在夏季和秋季与其他季节相比差异显著(P<0.05)。该项研究为乳品行业产品创新及牛乳营养价值升级提供可靠的技术支持。

In order to evaluate the influence of season on the fatty acid content of Holstein cow milk in Inner Mongolia,milk samples were collected from 10 large commercial pastures in Inner Mongolia during four seasons(spring,summer,autumn and winter)and analyzed for fatty acid content by gas chromatography(GC).The results showed that:1)the major fatty acids in Holstein cow milk from Inner Mongolia were palmitic acid,oleic acid,stearic acid,myristic acid and linoleic acid,which did not change due to geographical regions,cow breeds,feeds and processing methods;2)the proportions of saturated,monounsaturated and polyunsaturated fatty acids in the total fatty acids in cow milk were stable,and so were shortchain,medium-chain and long-chain fatty acids,which was not significantly affected by geographical regions;3)the major fatty acids in cow milk presented the same trend with season,being at higher levels in spring and at lower levels in summer and autumn;4)the contents of saturated and polyunsaturated fatty acids differed significantly(P<0.05)between summer and the other seasons and were lowest in summer,and the content of monounsaturated fatty acids differed significantly(P<0.05)between spring and summer and were also lowest in summer;and 5)the contents of short-chain and medium-chain fatty acids which have a strong influence on the flavor of milk fat differed significantly(P<0.05)in summer and autumn compared to the other seasons.This study may provide reliable technical support for product innovation in the dairy industry and the improvement of milk nutritional value.