A lack of correlation among fatty acids associated with different lipid classes in human milk

Sub-chronic (13-week) oral toxicity study, preceded by an in utero exposure phase and genotoxicity studies with fish source phosphatidylserine in rats

The safety of fish phosphatidylserine (PS) conjugated to DHA (InCog™) was examined in a series of toxicology studies as first step to support future use in infants and general population using in vitro genotoxicity tests and in a sub-chronic toxicity study with an in-utero exposure phase. PS is a major lipid in the cell membrane, active in various membrane-mediated processes. PS-DHA, present in human milk, has been suggested to be important for early brain development. Rats were exposed to diets containing 1.5%, 3% or 4.5% InCog or two control diets. Parental (F0) animals were fed throughout mating, gestation and lactation. Subsequently, a subchronic, 13-week study was conducted on the F1 animals followed by 4 weeks of recovery. The genotoxicity tests showed no mutagenicity potential. No significant toxicological findings were found in the F0 rats or the F1 pups. In the 13-weeks study, an increase in the presence of renal minimal-mild multifocal corticomedullary mineralization was noted in nine females of the high-dose group. This change was not associated with any inflammatory or degenerative changes in the kidneys. The no-observed-adverse-effect level (NOAEL) in the present study was placed at 3% in the diet (mid-dose group), equivalent to an overall intake of at least 2.1 g InCog/kg bw/day in the F1 generation.

Model for human milk fat substitute evaluation based on triacylglycerol composition profile

Being the dominant components in human milk fat (HMF), triacylglycerol (TAG) composition might be the best approximation index to represent the composing characteristics of HMF. In this study, TAG composition of HMF from different lactation stages was analyzed by RP-HPLC-APCI-MS, and the establishment of a model for the precise evaluation of human milk fat substitutes (HMFSs) based on TAG composition was indirectly realized by employment of fatty acid composition and distribution and polyunsaturated fatty acid (PUFA) and TAG compositions. The model was verified by the selected fats and oils with specific chemical compositions, and the results revealed the degrees of similarity of these fats and oils in different evaluation aspects reflected their differences in corresponding chemical composition with HMF. The newly established evaluation model with TAG composition as a comparison base could provide a more accurate method to evaluate HMFSs and might have some inspirations for HMFS production in the future.

Preparation of human milk fat substitutes from palm stearin with arachidonic and docosahexaenoic acid: combination of enzymatic and physical methods

Human milk fat substitutes (HMFSs) were prepared by a two-step process, namely, Lipozyme RM IM-catalyzed acidolysis of interesterified high-melting palm stearin with fatty acids from rapeseed oil and blending of the enzymatic product with the selected oils on the basis of the calculation model. The optimum conditions for the enzymatic reaction were a mole ratio of palm stearin/fatty acids 1:10, 60 °C, 8% enzyme load (wt % of substrates), 4 h, and 3.5% water content (wt % of enzyme); the enzymatic product contained 39.6% palmitic acid (PA), 83.7% of the fatty acids at sn-2 position were PA (sn-2 PA), and the distribution probability of PA at the sn-2 position among total PA (% sn-2 PA) was 70.5%. With the fatty acid profiles of human milk fat (HMF) as a preferable goal, a physical blending model was established for the second step to guarantee the maximum addition of selected oils. Based on the model prediction, a desirable formula constituted enzymatic product/rapeseed oil/sunflower oil/palm kernel oil/algal oil/microbial oil at a mole ratio of 1:0.28:0.40:0.36:0.015:0.017, and the final product had PA content, sn-2 PA, and %sn-2 PA at 23.5, 43.1, and 61.1%, respectively. The contents of arachidonic and docosahexaenoic acids were 0.4 and 0.3%, respectively. Relying on the total and sn-2 fatty acid compositions of HMF and "deducting score" principle, the score for the similarity between the final product and HMF was scaled as 89.2, indicating the potential as a fat substitute in infant formulas.

Lipases as biocatalysts for the synthesis of structured lipids

Structured lipids (SL) are broadly referred to as modified or synthetic oils and fats or lipids with functional or pharmaceutical applications. Some structured lipids, such as triglycerides that contain both long-chain (mainly essential) fatty acids and medium- or short-chain fatty acids and also artificial products that mimic the structure of natural materials, namely human milk fat substitutes and cocoa butter equivalents, have been discussed. Further, other modified or synthetic lipids, such as structured phospholipids and synthetic phenolic lipids are also included in this chapter. For all the products described in this chapter, enzymatic production in industry has been already conducted in one way or another. Cocoa butter equivalents, healthy oil containing medium-chain fatty acids, phosphatidyl serine, and phenol lipids from enzyme technology have been reported for commercial operation. As the demand for better quality functional lipids is increasing, the production of structured lipids becomes an interesting area. Thus, in this chapter we have discussed latest developments as well as present industrial situation of all commercially important structured lipids.

Lipase-catalyzed preparation of human milk fat substitutes from palm stearin in a solvent-free system

Human milk fat substitutes (HMFSs) were synthesized by lipozyme RM IM-catalyzed acidolysis of chemically interesterified palm stearin (mp = 58 °C) with mixed FAs from rapeseed oil, sunflower oil, palm kernel oil, stearic acid, and myristic acid in a solvent-free system. Response surface methodology (RSM) was used to model and optimize the reactions, and the factors chosen were reaction time, temperature, substrate molar ratio, and enzyme load. The optimal conditions generated from the models were as follows: reaction time, 3.4 h; temperature, 57 °C; substrate molar ratio, 14.6 mol/mol; and enzyme load, 10.7 wt % (by the weight of total substrates). Under these conditions, the contents of palmitic acid (PA) and PA at sn-2 position (sn-2 PA) were 29.7 and 62.8%, respectively, and other observed FAs were all within the range of FAs of HMF. The product was evaluated by the cited model, and a high score (85.8) was obtained, which indicated a high degree of similarity of the product to HMF.

Changes in the breast milk fatty acids and plasma lipids of nursing mothers following consumption of n-3 polyunsaturated fatty acid enriched eggs

The effect of chicken eggs enriched with n-3 fatty acids on breast milk and plasma fatty acids was determined in eight nursing women. The n-3 polyunsaturated fatty acid (PUFA) enriched eggs (n-3 eggs) contained 690 mg of n-3 fatty acid with 165 mg composed of longer chain n-3 fatty acid (C20:5 n-3, C22:5 n-3, and C22:6 n-3). Consuming two n-3 eggs as a part of their normal daily meal for 6 wk resulted in a significant (p < 0.05) deposition of total n-3 fatty acids at 3.6% compared with 1.9% for the pretest milk and a reduction in n-6:n-3 ratio (6.7 vs. 3.0). The C20 and C22 n-3 PUFA comprised 1.2% compared with 0.4% in the pretest milk (p < 0.05). Consuming n-3 eggs did not (p > 0.05) alter the C20:4 n-6 or the total n-6 fatty acid content of breast milk. Mean plasma total cholesterol and triglycerides were unchanged at the end of the 6-wk trial. Analysis of the breast milk lipids revealed increased (p < 0.05) predominance of n-6 and n-3 PUFA in the milk phospholipids over triglycerides. Positional distribution of phospholipid fatty acids indicated 20:4 n-6 and 20:5 n-3 in the sn-2 position, whereas the sn-1 position had increased levels of C16:0 and C18:0 (p < 0.05). The present study demonstrates that breast milk n-3 PUFA content can be increased without altering the plasma cholesterol or triglycerides when the n-3 PUFA eggs were consumed by nursing women.

Lymphatic fatty acids from rats fed human milk and formula containing coconut oil

Human milk and infant formula containing coconut/soy oil were infused into the duodenum of rats to determine the incorporation of capric, lauric, myristic and palmitic acids into lymphatic triacylglycerol (TAG). The proportion of capric and lauric acids in the lymphatic TAG reflected the fatty acid composition of the diet. Based on positional analysis, it appears that more than 50% of the capric and lauric acids could have been absorbed from the intestine as sn-2 monoacylglycerols. In the rats fed human milk, 50% of palmitic acid in lymphatic TAG was in the sn-2 position. Because of the nonrandom distribution of palmitic acid in the lymphatic TAG, the nonspecific lipase in human milk, i.e., bile salt-stimulated lipase, did not appear to be a factor in milk lipid digestion.