Production of human fat milk analogue containing α-linolenic acid by solvent-free enzymatic interesterification

Human milk fat (HMF) analogue was synthesized by lipase-catalysed interesterification of tripalmitin with extra virgin olive oil, and flaxseed oil in a solvent-free media. Lipozyme® TL IM, immobilized sn-1,3 specific lipase, was used as biocatalysts. Substrate molar ratio, reaction temperature and reaction time were used to model and to optimize the reaction conditions via response surface methodology. Good quadratic models were obtained for the incorporation of palmitic acid and α-linolenic acid. At the optimal conditions generated from the model, the palmitic acid and α-linolenic acid contents of the product were found to be 25.2g/100g and 15.9g/100g, respectively. The chemical properties (free fatty acid, iodine value, and saponification value), sn-2 positional fatty acid composition, and sterol composition of the final structured lipid (SL) were determined. Furthermore, the oxidative stability of the SL and the SLs with antioxidants (BHT, gallic acid, and rosemary extract) was evaluated. The peroxide and thiobarbituric acid reactive substances (TBARS) values of the SLs showed they had antioxidant activity on the SL. The HMF analogue synthesized in this study may have potential use in infant formulas to provide omega-3 fatty acids (α-linolenic acid).