Crystal morphology and interactions of binary and ternary mixtures of hydrogenated fats

摘要

Triacylglycerols undergo solid-to-liquid phase transitions between ambient and body temperatures. This reversible feature is highly desirable for many fats as functional ingredients for foods, providing properties such as structure, mouthfeel, and flavor delivery. The objective of this paper was to study the interactions in binary and ternary mixtures of commercial hydrogenated fats. The following properties were determined: (a) crystal morphology, by polarized light microscopy at temperatures of 30, 35, and 40℃; (b) solid fat content, by nuclear magnetic resonance, from 10 to 45℃; (c) consistency, by texture analysis, from 10 to 40℃. The diameters (μm) of the crystals were deduced from image analysis. The types of crystals observed were spherulites type A, and B and the polymorphic forms were β'. Crystal size increased from 30 to 35℃ and decreased from 35 to 40℃, due to the proximity of the melting point. Solid fat content and consistency were independent on interactions between the three components. The relative coefficients of the binary interactions were significant, showing an antagonistic effect, characteristic of eutectic interactions among triacylglycerols or between fats. A significant (p < 0.05) linear relationship between solid fat content and consistency was obtained.