Fat content and fatty acid composition of infant formulas.

Fat content and fatty acid composition of 25 commercial infant formulas sold in the Federal Republic of Germany and of 3 home-made milk formulas were analysed, using gravimetry of extracted lipids and high-resolution capillary gas-chromatography. Results were compared with the composition of human milk. Fat contents of all commercial formulas were similar to human milk values and met current recommendations, but 2 home-made preparations were at the upper and lower limits of the recommended range. Milk formulas tended to contain higher percentages of saturated and lower ones of cis-monounsaturated and trans-isomeric fatty acids than human milk. Linoleic acid (C18:2n-6) content was similar to human milk in most products but deviated clearly from recommended values in 2 home-made mixtures. Alpha-linolenic acid (C18:3n-3) values were often low in formulas, resulting a high n-6/n-3-ratios. In contrast to human milk, all formulas contained only minor amounts of the physiologically important long-chain polyunsaturated fatty acids with 20 and 22 carbon atoms. Some seasonal variation in the content of palmitic (C16:0), oleic (C18:1n-9), linoleic and trans-fatty acids was found when five arbitrarily selected adapted formulas were analysed repeatedly over one year. The composition of a home-made formula made from fresh cow's milk was markedly different in winter and in summer, when percentages of saturated and trans-fatty acids were higher and of linoleic acid were lower. We conclude that the composition of most commercial formulas is better suited to meet the lipid requirements of young infants than the home-made preparations investigated.(ABSTRACT TRUNCATED AT 250 WORDS)