Application of the similarity index to evaluate fat composition and structure in infant formulas

Abstract

Fat blends used in infant formulas (IFs) are designed to meet the required total fatty acid (FA) composition, rather than the regional distribution of FAs on the sn-2 and sn-1/3 positions of the glycerol backbone in triglycerides. The similarity index (SI) is a powerful parameter to compare complex fat blends and a reference fat source in terms of FA composition and structure and can be applied to design fat blends used in IFs. In the current paper, the SI is used to compare specific groups of IF differing in fat blend and a human milk (HM) fat reference. An important prerequisite for a robust SI is the analytical quality of the FA composition and structure measurements of both the HM fat reference and IFs. Overall, a higher average SI is observed in bovine milk fat-containing IF compared with palm oil-containing or palm oil-free IFs.