Comparison of methods for defatted human milk and nutrient composition: An experimental study

BACKGROUND: Human milk is considered the gold standard for infant nutrition; however, it is often discontinued in chylothorax and severe very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. As an alternative to complete human milk restriction, defatted human milk may be fed, though it may not fully support optimal infant growth and development. This study aimed to assess the micronutrient profile of defatted human milk. METHODS: Human milk was obtained from UCSD Human Milk Research Biorepository (San Diego, CA). Thirty samples representing 10 independent expressions in the morning, afternoon, and evening were pooled for analysis. Fat removal was performed by centrifugation at refrigerated and room temperatures, electric cream separator, and gravity separation. Analyses of macronutrients, micronutrients, fat-soluble vitamins, and water-soluble vitamins were conducted in triplicate. RESULTS: All defatting methods decreased vitamins A and E by >80%. Folate decreased most by nonrefrigerated centrifugation (52.3, SD < 0.01%) and least by cream separator (22.8, SD < 0.01%). Zinc decreased most by both nonrefrigerated centrifugation (43.5 ± 0.06%) and cream separator (43.5 ± 0.12%), and least by refrigerated centrifugation (17.7 ± 0.10%). Iodine decreased most by refrigerated centrifugation (40.0, SD < 0.01%) and least by cream separator (31.2, SD < 0.01%). Total triglycerides decreased most by refrigerated centrifugation (87.0 ± 0.03%). CONCLUSIONS: All defatting methods decreased amounts of vitamin A, vitamin E, folate, zinc, and iodine. Refrigerated centrifuge was most effective in removing total triglycerides. These results can inform fortification and supplementation guidelines of key micronutrients for patients with chylothorax and VLCAD deficiency consuming defatted human milk.