Sphingomyelin content of dairy protein ingredients and infant formula powders, and identification of bovine sphingomyelin species

Sphingomyelin (SM), a major sphingolipid in human and bovine milks, is an important structural component of neurons and lipid bilayers. Skimmed milk powders (SMPs), whey protein concentrates (WPCs), α-lactalbumin-enriched WPCs (α-lac WPC) and infant formula (IF) powders were evaluated for SM levels. Bovine SM species, studied using high performance liquid chromatography-mass spectrometry, did not vary across different production seasons. SM content was highest in one of the α-lac WPC ingredients evaluated. WPC 35 ingredients contained more SM than SMP. Varying SM contents of SMP from different suppliers appeared to be related to lipid content; varying SM contents of WPC 35 and α-lac WPC from different suppliers were likely due to differences in production processes. IF had SM contents within the human milk range. Supplementation of IF with a specific α-lac WPC to human milk α-lactalbumin levels can result in SM levels similar to those of human milk.