Milk fat as a structuring agent of plastic lipid bases

Abstract

The global legislation regarding the elimination of trans fat in foods has led to the need for technological solutions to produce plastic fats. Currently, the industrial method used to obtain lipid bases with different physical properties is the chemical interesterification of blends from hardfats and vegetable oils. Milk fat can be an alternative to this process, which is natural plastic fat, as a structurant to obtain plastic lipid bases containing vegetable oils. This study aimed to evaluate the ability of the anhydrous milk fat (AMF) to structure lipid bases made from AMF and high oleic sunflower oil (HOSO) (~80% oleic acid) blends. The blends were prepared in the following AMF:HOSO proportions (% w/w): 100:00 (control); 90:10; 80:20; 70:30; 60:40; and 50:50, and characterized for fatty acid and triacylglycerol composition, solid fat content, compatibility, melting point, thermal behavior of crystallization and melting, crystallization kinetics, microstructure, polymorphism and hardness. All blends showed compatibility between the constituents, which is fundamental for the stability of plastic fats. The anhydrous milk fat governed the crystallization of these lipid bases, presenting crystals of <30 μm of diameter, crystallized in polymorphic form β′. The blends 70:30, 60:40 and 50:50 AMF:HOSO exhibited suitable profile for technological applications in the food industry, characterized by a solid fat content lower than 32% at 10 °C, and higher than 10% at 21 °C, and melting point near the body temperature.