棕榈酸在三酰甘油中的位置分布对大鼠营养吸收的影响
2012-09-12刘亚东李晓敏杨丽杰
宋 秋,刘亚东,李晓敏,杨丽杰
(乳品科学教育部重点实验室,东北农业大学,黑龙江哈尔滨150030)
棕榈酸在三酰甘油中的位置分布对大鼠营养吸收的影响
宋 秋,刘亚东,李晓敏,杨丽杰*
(乳品科学教育部重点实验室,东北农业大学,黑龙江哈尔滨150030)
研究了棕榈酸在三酰甘油中的不同位置分布对脂肪酸及矿质元素吸收的影响。以幼龄雄性Wistar大鼠为动物模型,将含不同比例sn-2位棕榈酸的脂肪原料添加到无脂饲料中,分别为:OPO(1,3-二油酸-2-棕榈酸甘油酯)结构脂肪,组成模拟OPO的混合植物油,含OPO的婴儿配方奶粉以及常规婴儿配方奶粉。饲料实验脂肪含量均为10%,各组sn-2位棕榈酸相对含量分别为45.40%、13.29%、48.04%、28.66%。喂养两周后,分析大鼠粪便中的脂质及钙、镁元素。结果显示,OPO组和OPO婴儿配方奶粉组的大鼠对脂肪的吸收显著高于另外两组,并且钙排泄较少。由此可得出结论:高含量的sn-2位棕榈酸可以促进大鼠对脂肪的吸收,减少脂肪酸皂的形成,并能改善对钙的吸收。
棕榈酸,位置分布,脂肪,钙,吸收
Abstract:The impacts of the position of palmitic acid in triglyceride on the absorption of fatty acids and mineral were studied.Feeding experiment was performed by using four groups of young male Wistar rats.Fat raw materials with different proportions of sn-2 position palmitic acid were added into fat-free diets which were the OPO(1,3-dioleoyl-2-palmitoyl triglyceride) structural fat,the vegetable oil mixture with imitating the composition of OPO,the infant formula containing OPO and the common infant formula.The proportions of the experimental fat in each groups were all 10%,as for the sn-2 position palmitic acid in four groups were respectively 45.40%,13.29%,48.04%,and 28.66%.After 2 weeks feeding,the contents of lipid,calcium and magnesium in the fecal were analyzed.The results showed that the fat absorption after intake of OPO and the infant formula containing OPO were higher than the other two groups significantly with much less calcium excreting.In conclusion,high content of sn-2 position palmitic acid could promote the absorption of fat in rats,reduce the formation of fatty acid soap and improve the calcium absorption.
Key words:palmitic acid;positional distribution;fat;calcium;absorption
人类母乳中约含有2%~6%的脂肪,其中98%以上是三酰甘油,可以为婴儿提供约50%的能量[1-3],同时对于多种维生素和矿物质的吸收起到关键的作用,而且是婴儿身体的重要组成部分,对婴儿的生长发育有着重要意义。脂肪的消化主要在小肠进行,在肠道中,sn-1位和sn-3位的脂肪酸在消化酶的分解作用下从三酰甘油中释放出来而形成游离脂肪酸[4-6],并与连结在甘油基sn-2位上的脂肪酸一起被肠道吸收,再转化成婴儿所需要的能量与营养[7]。……
