Relating texture properties and composition of bovine fat tissue

Abstract

The relationship of various texture variables and fatty acid composition was studied in bovine kidney fat. Fat samples were obtained from 6 x 5 Brown Swiss bulls fed on one out of six diets containing different fats in order to achieve a high variability in depot fat composition. Melting curves, solid fat content, fatty acid composition, and three mechanical variables (cutting, extrusion, and adhesion force) were determined to characterize texture properties. Additionally, four sensory texture attributes (firmness, adhesiveness, friability, spreadability) were evaluated by manual inspection. Discriminant analyses showed that fatty acid composition as well as melting behaviour together with solid fat content are suitable to classify kidney fat according to the fat used in nutrition. Data obtained by mechanical and sensory texture measurements were less discriminative, All these texture attributes were closely correlated with each other. Extrusion force showed highest correlations with sensory attributes and therefore was considered to be most suitable to describe kidney fat characteristics beside melting behaviour and solid fat content. According to stepwise regression analyses, stearic acid, oleic acid, and fatty acids ≤C 16 were important to explain the texture characteristics of the fats analyzed. Melting behaviour and solid fat content could be best described by fatty acid composition (R 2 =0.73-0.94). However, in sensory and mechanical attributes, fatty acid composition on average accounted only for 54% of the variation with the closest relationship found for extrusion force (R 2 =0.78).