Comparative analysis of subcutaneous, tail, and internal fats in Awassi and Akkaraman sheep and lambs: fatty acid composition, health lipid indices, volatile compounds, thermal and physicochemical properties

This study investigates the effects of breed, age, and fat type on the volatile compounds, fatty acid composition, health lipid indices, thermal and physicochemical properties of subcutaneous, tail, and internal fat from Akkaraman and Awassi sheep. The most abundant volatile compounds identified were propionic, butyric, and acetic acids, along with ethanol and acetoin. Awassi fats had higher unsaturated fatty acids (ΣUFA 48.94%), higher levels of C18:1 (40.19%), higher ΣUFA/ΣSFA ratio (1.03) and a lower atherogenic index (AI 0.73), indicating potential cardiovascular benefits, whereas Akkaraman fats exhibited higher saturated fatty acids (ΣSFA 49.59%) and melting points, making them more suitable for industrial applications. Internal fat showed the highest onset (Tonset) and peak (Tpeak) temperatures than subcutaneous and tail fat in melting and crystallization peaks. Iodine value (IV) was lower in Akkaraman fat than in Awassi fat (p < 0.01). Melting point (MP) was higher in Akkaraman fat than in Awassi fat (p < 0.05). Saponification number (SN) was lowest in subcutaneous fat (p < 0.01). C18:1 correlated positively with C17:1, aldehyde, alcohol, acid, ketone, while C18:1 negatively correlating with C18:0 and fat type. Principal component analysis (PCA) indicated that age and fat type significantly influenced sample variance, with clear separation along PC1 (49.98%) by age and clustering of fat types along PC2 (18.57%). These findings suggest Awassi fat as a healthier dietary option based on lipid indices, while Akkaraman fat may have industrial applications. This study supports targeted breeding and fat utilization strategies in the food and health sectors.