文摘
Changes in the lipid composition of two standard infant formulas induced by 4 years of storage weredetermined. Lipids were thoroughly analyzed using different gas-liquid and liquid-liquid chromatographic techniques. Oleic acid and linoleic acid, which accounted for almost the total monounsaturatedand polyunsaturated fatty acids, respectively, showed slight but significant decreases (P < 0.05)during the 4 years of storage (from 41.52 to 39.83% for oleic acid and from 17.35 to 15.99% forlinoleic acid). Total trans fatty acid isomers showed low initial level (0.22% of total fatty acids), andsuch level remained unchanged during the storage period. Nonvolatile oxidation compounds includingoxidized, dimeric, and polymeric triglycerides did not significantly increase during the storage period,although a significant loss of tocopherols was found in the surface oil fraction (10-15%). In general,the results obtained indicate that, although small losses of oleic and linolenic acid as well astocopherols were found, the 4 year storage period did not lead to relevant changes in the lipid fractionof infant formulas.