The relationship between muscle fiber characteristics and meat quality of Longissimus dorsi muscle of pigs

Abstract

This experiment was designed to investigate the histochemical parameters of muscle fiber, and to estimate the correlation of muscle characteristics to meat quality traits in 63 crossbred pigs (Landrace x Large White x Duroc). Samples of the longissimus dorsi muscle were taken to evaluate the meat quality traits and histochemical characteristics using a combined NADH dehydrogenase and myofibrillar acid stabile ATPase reaction staining. Three muscle fiber types were detected, I, IIA, and IIB types. The results showed that type I, IIA, and IIB muscle fiber diameters were 40.12, 45.69, and 61.49 μm, respectively. For the percentage of muscle, the frequencies of type I and IIA were quite similar (19.93 and 15.98, respectively). Whereas, the IIB type presented the greatest proportion of muscle fibers (63.43). Fiber type was mainly related to and meat quality traits among various muscle fiber characteristics. The pH24 was negatively correlated to those of T24, a*, and b*(-0.38, -0.36, -0.37, respectively). L*value also negatively correlated with pH1 (r = -0.35). For pH24 and T1 showed positively correlated to WBS (r = 0.28 and 0.30, respectively), whereas T24 and L *value were negatively correlated with WBS (r = -0.26 and -0.30, respectively). Moreover diameter of type I and type I muscle fiber is positively correlated with WBS. The results suggested that pH values which reflect the early post-mortem metabolic rate are reliable parameters for prediction ultimate pork quality. The results imply that accelerated metabolic rate and poor meat quality could be partially explained by the decline of pH in muscle during early post-mortem.