Wang Chenlei,Yan Xinlei,Bai Yanping,Sun Lina,Zhao Lihua,Jin Ye,Su Lin
Sunit sheep are famous for their high meat quality, but the meat quality of them has declined due to the change in feeding methods. Lactobacillus has a variety of probiotic effects and is widely used in animal diets to optimize meat quality. This study aimed to investigate the effect of dietary supplementation with different levels of Lactobacillus on meat quality. A total of 24 3-month-old Sunit sheep with an average body weight of 19.03 ± 3.67 kg were randomly divided into control (C), 1% (L1), 2% (L2), and 3% Lactobacillus groups (L3), with 6 sheep in each group. Myofiber characteristics, meat quality, and metabolic enzyme activity were detected. Moreover, the regulatory mechanism of Lactobacillus on meat quality was explored by using Western blotting and real-time Quantitative polymerase chain reaction (RT-qPCR). The results showed that dietary addition of Lactobacillus decreased LDH activity in the Biceps femoris of Sunit sheep (P < 0.05). Compared to the other groups, the 1% Lactobacillus group showed the conversion of myofibers from the glycolytic to the oxidative type, and the increasing b* values (P < 0.05), decreasing shear force and cooking loss of meat (P < 0.05) and the relative gene and protein expression levels of AMPK, PGC-1α, NRF1, TFAM, and COX IV (P < 0.05) in the Biceps femoris were also increased in the 1% Lactobacillus group. Therefore, the addition of Lactobacillus to the diet of Sunit sheep could regulate the AMPK signaling pathway to promote myofiber type conversion, which improves meat quality. This study provided a theoretical and data basis for improving the meat quality of sheep and supplied a novel way of applying Lactobacillus.
Rui Liu,Man Qin,Keyue Li,Hai Yu,Mangang Wu,Wenbin Bao,Qingfeng Ge
Reactive oxygen species (ROS) have been recognized to have a significant impact on meat quality, while the role of the antioxidant system in response to ROS in postmortem muscle remain unclear. Protein DJ-1 serves as a sensor of oxidative stress and has an antioxidant function in biological systems. Hence, this study aimed to investigate the expression, oxidation, and interaction of protein DJ-1 in porcine longissimus thoracis (LT) and semimembranous (SM) muscles, as well as its correlation with meat quality, to gain a better understanding of meat quality formation during postmortem aging. The findings indicated significant variations in pH, L* , a* , purge loss, cooking loss, and Warner-Bratzler shear force (WBSF) between the muscle groups ( P < 0.05). The levels of reactive oxygen species (ROS), protein DJ-1, and oxidized DJ-1 (oxDJ-1) in SM muscle were higher than those in LT muscle throughout the 3 d of postmortem aging ( P < 0.05). Moreover, protein DJ-1 and oxDJ-1 were significantly associated with water holding capacity and a* value of pork ( P < 0.05). Through co-immunoprecipitation and mass spectrometry, a total of 23 DJ-1 interacting proteins were identified, mainly participating in glycolysis, energy metabolism, muscle contraction, resistance to oxidative stress, as well as amino acids biosynthesis and metabolism. These results suggest that DJ-1 may exert a regulatory influence on the development of pork quality during postmortem aging.
危险品化学品经营许可证（带存储）