Relationship between muscle fibre characteristics and meat sensory properties in three nutria (Myocastor coypus) colour types

The study determined the muscle fibre characteristics and sensory properties of the longissimus lumborum muscle (LL) of eight-month-old nutrias of three colour types and the correlations between meat histochemical measurements and eating quality. The following nutria colour types were used in the experiment: Standard (ST), Moravian Silver (MS), and Prestice Multicolour (PM). The nutria colour type significantly (P < 0.001) affected the number of type IIB fibres with the lowest number in ST (108 per mm2). The proportion of type I fibres varied between 10.6 and 14.2%; type IIA fibres varied between 6.1 and 7.8%; and type IIB fibres varied between 78.2 and 83.4% and it was not affected by colour type. The cross-sectional area (CSA) was 2.565–2.841 µm2 in type I, 2.867–3.010 µm2 in type IIA, and 4.698–5.517 µm2 in type IIB fibres. The CSA of type IIB fibres (P < 0.001) was the largest in ST. The sensory trait of tenderness (P < 0.05) was the lowest in MS. Correlations between the proportion of fibres and sensory traits were not observed. The CSA of type I fibres correlated with flavour (0.19) and the CSA of type IIB fibres with tenderness (0.10).