The future of enzymatic glycerolysis: scale-up and adipose tissue mimetics

Abstract: Substituting animal-based fats with plant-based fats with similar stability and functionality has always been a big challenge for the food industry. Despite the excellent performance of palm oil and its fractions in food products, the food industry needs to find healthier and more sustainable alternatives. Enzymatic glycerolysis (GL) converts liquid oils into a solid fat through the conversion of triacylglycerols in liquid oils into monoacylglycerols (MAGs) and diacylglycerols (DAGs) and can be a viable choice for food manufacturers to replace tropical and hydrogenated oils. Production of MAGs and DAGs alters the crystallization behavior of native oil and contributes to unique structural characteristics of glycerolysis products (GPs). In addition, these natural components are of great interest due to their nutritional benefits on lipid metabolism such as inhibiting body fat accumulation and reducing serum postprandial triglyceride level. Here we report on the modification and scaling up of enzymatic GL process of different plant oils including palm olein, tigernut, peanut, cottonseed, and rice bran. GPs were then utilized as the oil phase of ethylcellulose (EC) oleogels, prepared by EC with different molecular weights (20 cP, and 45 cP) at 5% w/w level. Findings derived from the preliminary scale-up study suggested that the GL process is easily scalable to the pilot plant, indicative of its commercial potential. Dramatic changes in the crystallization behavior, solid fat content, and microstructure were found after GL. Oil systems containing higher levels of both saturated fatty acids and monounsaturated fatty acids, such as tigernut oil and palm olein, displayed high plasticity and broad melting peaks with high melting temperatures, similar to animal fat. A combination of GL and oleogelation produced a more deformable and cohesive product. Comparison of the melting, rheological and mechanical properties of the EC oleogels with those of whole pork, beef and lamb adipose tissue showed the potential for EC oleogels of oil glycerolysis products to be used as adipose tissue mimetics in the new generation plant-based meat analogs.