Influence of fat structure on the mechanical properties of commercial pate products

Five commercial brand pâtés were characterized by examining their texture, microstructure, fatty acid composition, melting profile, and polymorphism. Pâtés evaluated at 4°C showed much higher hardness values compared to when tested at 22°C. Pâtés with higher fat content and higher saturated fatty acid and triacylglycerol contents were found to be harder. Smaller fat globules were also found to be correlated to higher hardness values. Increases in solid fat content were correlated to an increased hardness at 4°C vs. room temperature but could not explain differences observed at a specific temperature. Powder X-ray diffraction studies demonstrated that while the fat extracted from one of the pâtés crystallized in a β polymorphic form; while embedded in a pate protein matrix, it was crystallized in a β' polymorphic form. This implies an effect of the food matrix on fat crystallization and structure and an interaction between fat and other components present in the food matrix.