CHEMICAL AND ENZYMATIC INTERESTERIFICATION OF STRUCTURED LIPIDS WITH DIFFERENT SOLID CONTENTS: A COMPARATIVE STUDY

Due to the increasing concern about the consumption of trans fatty acids, their nutritional effects on health, and the ban on their use, interesterification has become a viable method for the production of fats with low or no trans isomer content. This has promoted the synthesis of structured lipids (SLs) by chemical and enzymatic interesterification. During synthesis, the position of the fatty acids in the triacylglycerol molecules (TAG) is rearranged, simultaneously, forming new bonds. This can lead to desirable physicochemical properties from a technological point of view. However, the partial replacement of hydrogenated fats presents some challenges, such as the difficulty in obtaining suitable solid fat content (SFC) and plasticity. The aim of this study was to compare the effects of chemical and enzymatic interesterification reactions on the physicochemical behavior of SLs prepared with different oils (soybean, peanut, and fully hydrogenated crambe oil (FHCO)) at different FHCO concentrations (low, medium, and high). Synthesis was performed by chemical interesterification with sodium methoxide and enzymatically with commercial lipase and fatty acids (FA) composition, TAG, SFC and thermal behavior were evaluated. Both syntheses showed interesting FA in terms of essential monounsaturated and polyunsaturated FA and desirable saturated FA to increase SFC. The content of TAG was above 90%, proving that hydrolysis followed by esterification occurred. Both interesterification processes led to an increase in monounsaturated and diunsaturated TAGs, with triunsaturated TAGs found only in SLs with high hardfat concentrations, causing a change in thermal behavior during crystallization. SLs from enzymatic interesterification showed a lower SFC compared to SLs from chemical transesterification, which exhibited a more linear SFC. Chemically and enzymatically interesterified SLs showed different physicochemical behavior when used in the same formulations, indicating that they are effective in lipid modification processes with properties suitable for food applications and are alternatives to partially hydrogenated fats.