Critical Factors Affecting the Quality of the Longissimus Lumborum from Native Thai Cattle (Bos indicus)

Abstract

Colour is one of the important parameters determining the purchasing decision of consumer and it’s also become a challenging errand for the meat industry. The colour of meat itself is administered by the concentration and redox stage of myoglobin which that myoglobin underwent denaturation and oxidation in the presence of external triggers such as pH and temperature. Hence this study aimed to investigate the effect of chilled storage on the physicochemical changes and oxidative deterioration of Longissimus lumborum and their interrelationships between these traits from native Thai cattle. Physicochemical changes and oxidative deterioration of the Longissimus lumborum from native Thai cattle (n=3 female, 36 months, live wt. 350 kg) during storage at 5ºC from day 0 to 7 was investigated. Muscle pH decreased (6.26±0.05 to 5.53±0.32) and expressible drip increased (9.74 to 20.66) during storage and were highly correlated (R2 = 0.97). Autooxidation of oxymyoglobin followed a first-order kinetic model as steaks became more discolored as the redness index (a*/b*) decreased over time (1.55±0.12 to 1.02±0.05). Lipid oxidation increased during storage, where the thiobarbituric acid reactive substances (TBARS) (0.98±0.02 to 1.25±0.01) and it was correlated with percentage metmyoglobin (R2 = 0.91). Longissimus lumborum from native Thai cattle developed PSE-like meat as it became paler (greater L* values) soft and exudative (greater values for expressible drip and cooking losses). Values for muscle hardness gradually declined during storage, indicating a greater tenderness after 7 days of aging. Therefore, it can be concluded that these data indicate that the meat from native Thai cattle improved by controlling the critical factors (muscle pH, expressible drip, cooling losses, meat color, and color stability) during rigor development and post-mortem storage.