Determination of the relationship between mutton flavour and fat types obtained from different ages of sheep (akkaraman and awassi)

In this study, physicochemical and technological properties of subcutaneous, tail and internal fat of 12 and 36 months Akkaraman and Awassi sheep were evaluated. Moisture content, total fat content, total nitrogenous components, fat yield, fatty acid composition, free fatty acidity, melting and crystallization curves of fats by differential scanning calorimetry (DSC), iodine number, saponification number, melting points and volatile compounds were determined. The moisture content of lamb (12 months) fat (9.34%) was lower than that of sheep (36 months) (12.00%). The highest fat content (89.55%) was found in Akkaraman lamb groups (p<0.05). The highest (0.81%) total nitrogenous constituent content was observed in subcutaneous fat (p<0.01). The lowest fat yield (54.64%) was observed in Awassi subcutaneous fat (p<0.01). Total MUFA (39.89%), total UFA (42.97%) and UFA/SFA ratio (0.78) in Akkaraman adipose tissues were lower than those of Awassi (total TDYA: 45.30%, total DMYA: 48.94%, DMYA/DYA: 1.03), whereas total SFA (58.12%), atherogenicity (AI: 0.97) and thrombogenicity (TI: 2.64) index values in Akkaraman were higher than those of Awassi (ƩSFA: 49.59%, AI: 0.73, TI: 1.86). The highest C14:1 (1.30%), C16:1 (4.79%) and C18:1 (43.01%) contents were found in sheep tail fat, while the lowest C14:1 (0.05%), C16:1 (1.04%) and C18:1 (30.61%) contents were found in sheep blended fat (p<0.05). The lowest (15.22%) C18:0 content was found in tail fat. In the 1st melting peak values, the highest values of Tonset (-4.65 ºC) and TPeak (6.64 ºC) were determined in blended fat, while the lowest values of Tonset (-11.47 ºC) and TPeak (-0.28 ºC) were found in the tail fat. The highest 1st melting ΔH value was determined in subcutaneous (63.88 J/g) fats and the lowest ΔH value was determined in blended (47.67 J/g) fats. In the 2nd melting peak values, Tonset (23.98 ºC) and TPeak (39.19 ºC) values of Akkaraman were higher. In the 2nd melting peak values, ΔH (37.24 J/g) values of Akkaraman were higher than ΔH (25.95 J/g) values of Awassi. The 1st and 2nd crystallization values of Tonset (28.52 ºC, 10.97 ºC) and Tpeak (24.96 ºC, 5.61 ºC) of Akkaraman fats were higher than the values of Tonset (22.77 ºC, 5.46 ºC) and Tpeak (18.50 ºC, 0.87 ºC) of Awassi. In the 1st crystallization, Awassi had higher ΔH value (-11.45 J/g). The highest free fatty acidity (0.61%) was observed in blended fat (p<0.01). The lowest saponification number (188.10 mg KOH/g fat) was observed in subcutaneous fats (p<0.01). The highest iodine number was found in tail fat (41.00 g/100g fat). The highest (43.24 ℃) melting point was observed in blended fat (p<0.01). The L* value of Akkaraman fat tissues (84.63) was higher than that of Awassi (82.31) (p<0.01). The a* and b* values of blended fat were higher than those of tail and subcutaneous fats. The volatile compounds found in the highest amounts in fats were propionic, butyric, acetic acids, ethanol and acetoin. No positive or negative correlations were observed between margaric acid (C17:0) with breed, age, fat types, volatile compounds. Awassi sheep fats can be used in the food industry and in products aimed at health-conscious consumers. Keywords: Blended Fat, DSC, Fatty Acid Indices, Subcutaneous Fat, Tail Fat, Volatile Compounds