Enzymatic synthesis of structured lipids containing DHA, ARA, capric, and palmitic acids suitable for use as fat blend in infant formula

Abstract

A structured lipid (SL) with substantial amount of palmitic acid at the sn-2 position and enriched with capric acid (C), was produced in two enzymatic interesterification stages by using immobilized lipase, Lipozyme® TL IM (Novozymes North America Inc., Franklinton, NC). The substrates for the reactions were high melting point palm stearin (HMPS), high oleic sunflower oil (HOSO) and tricaprin (TC). The SL was characterized for total and positional fatty acid (FA) profiles, triacylglycerol (TAG) molecular species, free fatty acid content, melting and crystallization profiles. The final SL contained 20.13 mol% of total palmitic acid from which nearly 40% was located at the sn-2 position. The total capric acid content was 21.22 mol%, mostly at the sn-1 and sn-3 positions. The predominant TAGs in the SL were OPO, POP and CLC. The melting completion and crystallization onset temperatures of the SL were 27.7°C and 6.1°C, respectively. The yield for the overall reaction was 90 wt%. This SL might be totally or partially used in commercial fat blends for infant formula.