Nutritional Value Evaluation Of The OPO Structured Fat

Human milk is considered to be the best nutritional and ideal food for infants during the first part of their live. Huamn milk fat not only constitutes more than50%of the energy, but also is an important source of neural tissue composition. The fat is a remarkable example of stereo-specific positioning of fatty acids with structures that are highly conserved and unusual. Not only does human milk contain high amounts palmitic acid (C16:0), but approximately70%of the palmitic acid is esterified at the TG stereo-specifically numbered sn-2position, with preferential positioning of C18:1(n-9) and C18:2(n-6) at the sn-1,3positions. Infant formula is by far the best substitutes of human milk. In cow’s milk fat or in vegetable oils, commonly used in infant formulas, palmitic acid is predominantly esterified to the external sn-1and sn-3positions, with relatively little incorporation at the sn-2position. During hydrolysis by several TG lipases in the digestive tract, palmitic acids located at the sn-1,3positions are released as free fatty acids which will bind to calcium when present at a high concentration in the intestinal tract and make highly-insoluble-calcium soaps. Formation of calcium soaps caused loss of energy as well as loss of calcium. Additionally, the highly-insoluble-calcium soaps will make the Infant’s stool hardens, and then led to constipation. The development of an interesterification process that yields triglycerides rich in sn-2palmitic acid has lead to the formulation of a commerical product, OPO (1,3-dioleoyl-2-palmitoyl triglyceride) structured fat, which mimics human milk fat in fatty acid profile and in sn-2palmitic acid content. The issue mainly studys on its functionality, simultaneously investigates and analysises the fat conditions of human milk and infant formulas sold.Fatty acid profiles and stereo-specific structure of mature human milk, cow’s milk and mare’s milk fat were analyzed through gas chromatography. Mature Human milk had low saturated fatty acids, high monounsaturated fatty acids and high linolenic acid. The contents of saturated fatty acids in cow’s milk and mare’s milk were the highest, with up to66.61%in cow’s milk, and amounted to44%for long-chain saturated fatty acids. But in mare’s milk, short-chain fatty acids accounted for more than half of the total saturated fatty acid. In human milk, palmitic acid was preferentially esterified at the sn-2position (84.53%), and oleic and linoleic acids were predominantly esterified at the sn-1,3positions (19.33%and14.60%, respectively, in the sn-2position). In mare’s milk,64%palmitic acid is in the sn-2position of TG, that keeps consistent with human milk, and both are significantly higher than cow’s milk of31%. The proportion of relative saturated fatty acids at the sn-2position increased as the carbon chain lengthened from8to16carbons, cow’s milk is not the law.Fatty acid composition and structure determinations were made of12brands of infant formulas(Ⅰ)sold in the Chinese market。 Infant formulas resemble the fatty acid profile of human milk, but the distribution of fatty acids at the sn-2position is markedly different. In most of infant formulas, palmitic acid was preferentially esterified at the sn-1,3positions and oleic and linoleic acids had higher percentages at the sn-2position than they do in human milk.OPO structured fat and vegetable oils used in infant formula milk powder for determination of fatty acid composition and structure. Fat measured OPO structured fat contains a main of7main fatty acids in human milk, and similar content, the proportion of relative palmitic acid, and oleic acid at sn-2position47.03%and26.31%, respectively. According to the survey data, composed of four kinds of vegetable oil mixture, mixture of make it according to the certain proportion of OPO and fatty acid composition of fat the same structure, as a further test of the control group. Select coconut oil as a major source of medium-chain saturated fatty acids, Palm oil as the main source of palmitic acid, olive oil as the principal source of oleic acid, soybean oil as the main source of linoleic acid, determine the selected soybean oil, coconut oil, palm oil, and olive oil proportion is26:18:30:26.The absorption of OPO structured fat was assessed through experiments. Feeding experiment was performed by using four groups of young male Wistar rats. Fat raw materials with different proportions of sn-2position palmitic acid were added into fat-free diets which were the OPO structured fat, the vegetable oil mixture with imitating the composition of OPO, the infant formula containing OPO and the common infant formula.One week after adaptation, the rats were lavaged using the liquid feed above, and results show that with fat in the small intestine of the OPO group, contents of palmitic acid are significantly lower than the other two, significantly higher than ordinary milk group-controlled oil group, illustrating that OPO palmitic acid absorption of structured fat.After two weeks feeding, the contents of lipid, calcium and magnesium in the fecal and plasma lipids were analyzed. The sn-2position palmitic acids in four groups were respectively45.40%,13.29%,48.04%, and28.66%.Fat excretion of the groups96mg,202mg,90mg and162mg, respectively, and excretion of free fatty acid level and this negative correlation, and OPO formula and OPO structured fat groups there is no significant difference, with OPO and regular formula group and control significant differences among groups of oils and fats. Fecal excretion of palmitic acid and fat has consistent rules. That OPO structured fat can promote the absorption of fat, palmitic acid in the sn-2more easily be absorbed. OPO structured fat and OPO formula groups contents of fecal calprotectin is significantly lower than the control group of oils, calcium apparent absorption associated with the negative, that OPO structured fat intake reduces the formation of calcium soaps.The fatty acid composition of infant formulas in markets was similar to human milk, but the structure was significant different. OPO structured fat simulation on the distribution of fatty acids from human milk fat, with a high content of sn-2of palmitic acid, added to infant formula can promote the absorption of fat, reducing the formation of fatty acid soap, and to improve the absorption of calcium. This study will prove an important theoretical and practical basis about simulated human milk structure fat for infant formula.