Effect of High-Pressure Treatment on Stress Relaxation Characteristics of Refrigerated Tan Sheep Muscle Investigated by Cysteine Oxidative Modification Proteomics
GAO Yurong, BU Ningxia, ZHANG Rui, WANG Suye, LIU Dunhua
1. College of Food Science and Engineering, Ningxia University, Yinchuan 750021, China; 2. College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China
Abstract：The current study used cysteine oxidative modification proteomics to investigate the correlation between oxidative modification of cysteine (Cys) and stress relaxation characteristics in Tan sheep muscle subjected to high-pressure (HP) treatments at 200 or 500 MPa for 15 min at 18 ℃ and stored for 1, 3 and 7 days at 4 ℃. The results showed that muscle hardness and elasticity were significantly higher following HP treatments compared to the non-treated (NT) group (P < 0.05). Most stress relaxation indexes were higher in the HP-treated groups than in the CN group. During all storage periods, the carbonyl value of the 500 MPa treated group was significantly higher, and the total sulfhydryl content was significantly lower than that of the 200 MPa treated group (P < 0.05). A total of 388 significantly differential oxidation sites were identified, of which 15 were significantly correlated with at least one indicator of stress relaxation (P < 0.05), involving myosin (Cys32705, Cys29171, Cys26405, and Cys32358), concomitant actin (Cys5628), myosin binding protein H (Cys481), myosin heavy chain 8 (Cys403), membrane-associated protein (Cys292), myosin heavy chain 11 (Cys701), L-lactate dehydrogenase (Cys315), glycogen phosphorylase (Cys496), phosphoglucose translocase 1 (Cys407 and Cys134), pyruvate kinase (Cys510) and calcium transporter ATPase (Cy651). Therefore, high-pressure treatment induces oxidative modification of some oxidation sites of structural proteins in sheep muscle and consequent protein denaturation and aggregation, in turn reducing the degradation of proteins and inducing a decrease the hardness of Tan sheep meat.
2024, Vol. 38 
