Medium-long-medium (MLM) structured lipid (SL) as a new SL is a potential functional ingredient in food and nutraceutical products, but its composition-structure-physicochemical properties relationship has not been revealed in food industry. MLM type of medium-long chain triacylglycerol (MLCT) was synthesized from Camellia oil by combi-lipase; its physicochemical properties and composition-structure relationship were investigated in this research. The higher MLCT (67.24% ± 0.09) and MLM (52.71% ± 0.53) productivities were achieved after parameter optimization. The physicochemical characterization of SLs exhibited mild thermal property, intermediate Fourier transform infrared spectroscopy absorption intensity, and better crystal morphology. Joint characterizations identified that MLM and long-medium-long type SL were rich in 1,3-dioctanoyl-2-linoleoyl glyceride (CaLCa), 1,3-dioctanoyl-2-oleoyl glyceride (CaOCa), 1,3-dilinoleoyl-2-octanoyl glyceride (LCaL), and 1,3-dilinoleoyl-2-decanoyl glyceride (LCL) components, respectively. This is ascribed to the higher proportion of caprylic and linoleic acid in 1,3-specific enzyme. The 3D structural analysis further demonstrated that the CaLCa, CaOCa, LCaL, and LCL molecules had lower steric energy to form symmetrical structure at 1,3-position. This research provides a practical method to produce MLM-type SL from edible oils and fats in food industry.
Keywords: 3D molecular structure; camellia oil; combi-lipase lipozyme TL IM/RM IM; enzymatic interesterification; medium-long-medium structured lipid.
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