Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: [Email]
This research aimed to explore the role of protein S-nitrosylation in regulating the tenderness of postmortem beef, from the perspective of μ-calpain autolysis and protein proteolysis. Five bovine semimembranosus muscles were incubated with three treatments including S-nitrosoglutathione (GSNO, nitric oxide donor), normal saline and Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME, nitric oxide synthase inhibitor). The results showed that the level of protein S-nitrosylation was improved by GSNO treatment and reduced by L-NAME treatment (p < 0.05). Compared to the control, GSNO treatment had higher shear force while L-NAME treatment presented lower shear force at 7 d postmortem (p < 0.05). In addition, μ-calpain autolysis, myofibrillar protein and desmin degradation were reduced by GSNO treatment and accelerated by L-NAME treatment (p < 0.05). Therefore, it can be speculated that protein S-nitrosylation could affect beef tenderization by regulating the autolysis of μ-calpain and the degradation of myofibrillar proteins.