Investigation of fatty acid composition, thermal and rheological behavior of yak, cow and horse fats

The objective of this paper was to study the fatty acid composition, and thermal and rheological behavior of Kyrgyz yak (Bos grunniens) visceral fats compared to visceral fats of cow (Bos taurus) and horse (Equus caballus). The result of the studу revealed that the content of saturated fatty acids (SFA) in yak fat was higher than those of unsaturated fatty acids (UFA) (about 58.3 and 38.0 %, respectively). The UFA content in yak fat was higher compared to cow fat (about 27.1 %) and lower than that of horse fat (about 60.0 %). The melting temperatures determined using DSC were found to be 55.18±0.71, 54.98±3.01, 37.60±1.92 °C for yak, cow and horse fat, respectively. These results were close to the solid-liquid transition temperature determined by oscillation rheology (52.20±0.89 °C for yak, 53.56±3.53 °C for cow and 33.7±1.84 °C for horse fat). Rotational rheological measurements at 35 °C have shown that yak fat had shear thinning flow behavior with high a viscosity of 226 mPas compared to horse fat, which has Newtonian flow behavior with a viscosity of about 36 mPas (γ=100s-1). Results on properties obtained in this study will help to understand the contribution of yak fats to the structural properties of new products with these alternative fat sources