Predicting Meat Tenderness From Muscle Tensile Properties

Abstract Two major types of objective measurements were performed on raw porcine psoas muscle (I ‐ shearing and breaking strength tests; II ‐ sarcomere length, elasticity, stress relaxation and break elongation) and compared with taste panel evaluation (tenderness, elasticity, and chew count) of cooked meat. A standard sample of texturized vegetable protein used as a reference by the panel proved useful in reducing variations between the chew count test and the objective evaluation; it was not of significant value with the other sensory evaluations. No significant correlations were found between the two groups of objective measurements. Breaking strengths of small longitudinal strips of tissue, following a brief cyclic or extension stretching on the Instron, were the best predictors of sensory tenderness accounting for 59–90% of variation. Other measurements also gave significant correlations. The major source of variation in breaking strength values was the variation between animals, but the post‐mortem treatment (restraining versus not restraining during rigor) and the interaction between animals and the post‐mortem treatment also were significant in some cases. Breaking strengths of uncooked samples from the same muscle showed a coefficient of variation of up to 54%. It is concluded that there are two major structural contributions of raw muscle to cooked meat tenderness, a connective tissue factor and a contraction factor; different objective methods are best suited for their evaluation.