The Lipid and Glyceride Profiles of Infant Formula Differ by Manufacturer, Region and Date Sold

We tested the hypothesis that the lipid composition of infant formula is consistent between manufacturers, countries and target demographic. We developed techniques to profile the lipid and glyceride fraction of milk and formula in a high throughput fashion. Formula from principal brands in the UK (2017–2019; bovine-, caprine-, soya-based), the Netherlands (2018; bovine-based) and South Africa (2018; bovine-based) were profiled along with fresh British animal and soya milk and skimmed milk powder. We found that the lipid and glyceride composition of infant formula differed by region, manufacturer and date of manufacture. The formulations within some brands, aimed at different target age ranges, differed considerably where others were similar across the range. Soya lecithin and milk lipids had characteristic phospholipid profiles. Particular sources of fat, such as coconut oil, were also easy to distinguish. Docosahexaenoic acid is typically found in triglycerides rather than phospholipids in formula. The variety by region, manufacturer, date of manufacture and sub-type for target demographics lead to an array of lipid profiles in formula. This makes it impossible to predict its molecular profile. Without detailed profile of the formula fed to infants, it is difficult to characterise the relationship between infant nutrition and their growth and development.

Relationship between trisaturated glyceride composition and the softening point of milk fat

SummaryNo relationship was found between the trisaturated glyceride content and the softening point (SP) of milk fat. Inter-esterification of milk fat increased its SP, but did not change the trisaturated glyceride content or the fatty acid composition of the trisaturated glyceride fraction. Inter-esterification increased the amount of both low and high and decreased the amount of medium molecular weight triglyceride species in the trisaturated glyceride fraction. The increase in the amount of high molecular weight triglyceride species was up to 3 times greater than the increase in the amount of low molecular weight triglycerides.The triglyceride species composition of the trisaturated glyceride fraction of milk fat was found to vary seasonally. Excellent correlation was found between SP and groups of low molecular weight triglycerides, groups of high molecular weight triglycerides and some individual triglyceride species. Correlation coefficients were higher than those previously reported between groups of fatty acids and SP.

FURTHER STUDIES ON LIPOTROPISM IN THE DOMESTIC DUCK (White Pekin)

On choline-free diets containing 10, 18, and 28% casein, the total liver lipids of ducklings were found to be 34.8, 25.0, and 13.8% respectively. Supplementation of the 10% casein diet with 0.5% methionine increased the liver lipids. The same amino acid has no effect at the intermediate level of casein while it is lipotropic at the 28% casein level. In similar experiments with a purified soybean protein (low in methionine) fed at levels of 12, 21.7, and 27.9%, the liver lipids were 31.8, 26.6, and 27.6% respectively. These values do not differ significantly from each other. Methionine was found to be lipotropic at any of these three levels of soybean protein, and more so as the level of the soybean protein increased in the diet. From these results, it is concluded that the purified soybean protein used is a nonlipotropic protein, while casein is definitely lipotropic in ducklings. The lipotropic activity of methionine is closely related to the quality and quantity of the protein in the diet. On high fat diets containing 22, 32, and 42% fat, choline had no lipotropic effect. The average liver lipids for all groups ranged from 11 to 15%. High fat diets are less inducive of fatty livers than high carbohydrate diets. Ducklings fed a fat-free, choline-free basal diet presented livers with an average total lipids of 18%. Supplementing the basal diet with 1% cholesterol increased the liver lipids to 22%. Inositol is lipotropic either in the presence or absence of cholesterol, but choline was much more effective under similar conditions. The two lipotropic factors have a synergistic action and the reduction of the liver lipids is primarily on the glyceride fraction. Cholesteryl ester was at its lowest value in the group fed the basal diet supplemented with inositol only.