Meat quality is closely related to consumer experience and the benefits of deep processing enterprises, and it is influenced by diverse and complex factors. Recently, the impact of ubiquitination on meat quality has attracted increasing attention, and multiple studies have confirmed its crucial role in meat quality. This paper reviews the literature on the effect of ubiquitination on postmortem muscle energy metabolism, and discusses the potential mechanisms through which ubiquitination affects meat tenderness, color, water-holding capacity, and fat content. Furthermore, it highlights the regulatory mechanisms of protein ubiquitination on meat tenderness in terms of the ubiquitin-proteasome system and the apoptotic pathway. This review is anticipated to enhance the understanding the mechanism through which ubiquitination affects meat quality, thereby laying a theoretical foundation for regulating meat quality through ubiquitination.

Oxidation and microbial spoilage are the major factors affecting the quality and shelf life of meat and meat products. Phenolic compounds extracted from plants have antioxidant capacity and antibacterial properties. But their antibacterial mechanisms have not been clearly elaborated and a systematic review in this field is still lacking. Based on the classification of and the variability of the antibacterial activity of natural phenolic compounds, the possible antibacterial mechanism of phenolic compounds is summarized from the perspectives of the cell wall and membrane, biofilm formation and protein synthesis, and their application in the meat industry is reviewed. This paper is expected to provide a theoretical foundation for further research on the antibacterial mechanism of natural phenolic compounds and their application in meat production to extend the shelf life of meat and meat products.

As a key indicator to measure meat quality, meat color has always been the focus of attention in the meat industry. A large number of reactive oxygen species (ROS) are produced in the freshly slaughtered cattle carcass due to hypoxia and ischemia. The accumulation of ROS resultes in oxidative stress of the carcass, which further promotes the oxidation of myoglobin and adversely affectes the flesh color. However, currently there are few systematic reviews examining the effect of oxidative stress on meat color and its stability. In this article, the effects of oxidative stress on meat color and meat color stability are reviewed by regulating lipid oxidation, protein oxidation and degradation, and affecting the function of mitochondria to provide a theoretical rationale for maintaining good meat color by controlling post-mortem oxidative stress in the future.

The growth and metabolism of microorganisms is the main cause of meat spoilage. The rapid and nondestructive techniques for detecting microorganisms in meat have attracted more and more attentions. Spectroscopic techniques such as Raman spectroscopy, infrared spectroscopy and spectral imaging show great advantages in rapid and non-destructive detection, but their application in meat spoilage detection has not been timely summarized. Based on an overview of the dominant spoilage organisms and microbial metabolism in meat under different storage conditions, this paper briefly describes the material basis for spectroscopic prediction of meat spoilage. Then, the application of Raman spectroscopy, infrared spectroscopy and spectral imaging technology in predicting the shelf life of meat is summarized. The efficiency of predictive modeling of meat shelf life based on total bacterial count or total volatile basic nitrogen (TVB-N) content and problems existing in this field are highlighted. We anticipate that this review will provide new ideas and theoretical guidance for the development and application of rapid and nondestructive techniques for meat spoilage identification.

To investigate the effect of dietary addition of Bacillus subtilis on the antioxidant capacity, meat color, protein oxidation, lipid oxidation and sensory quality of pork during storage in high-oxygen modified atmosphere packaging, 12 Duroc × Landrace × Yorkshire pigs were equally allocated into 2 groups that were fed a basal diet alone and in combination with B. subtilis, respectively. Following slaughter, the longissimus dorsi muscle was taken and cut into two parts: one part was used to measure the activity of antioxidant enzymes; the other part was packaged under high oxygen conditions and stored at 4 ℃. The meat color and the contents of malondialdehyde (MDA), carbonyl, and sulfhydryl were measured after 0, 5, 10, 15, and 20 d, and sensory evaluation was performed. The results demonstrated that the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) significantly increased in the B. subtilis supplementation group compared with those in the control group (P < 0.05). Furthermore, dietary supplementation with B. subtilis significantly improved the color of pork stored in high-oxygen modified atmosphere packaging (P < 0.05). During low-temperature storage, dietary supplementation with B. subtilis decreased the MDA content (P < 0.05) and inhibited the lipid oxidation of pork stored in high-oxygen modified packaging. In addition, it significantly inhibited the formation of carbonyl compounds and the loss of sulfhydryl compounds (P < 0.05), and significantly increased the sensory color score of high-oxygen modified atmosphere packaged pork and the overall preference score after opening the package (P < 0.05). In summary, dietary addition of B. subtilis could improve the antioxidant capacity of pork, thereby maintaining the color and inhibiting protein and lipid oxidation in pork stored in high-oxygen modified atmosphere packaging, ultimately enhancing the eating quality of pork.

To elucidate the effect of the calcium-independent phospholipase A₂ (iPLA₂) activity of peroxiredoxin 6 (Prdx6) on beef tenderization and the underlying mechanism of action during the postmortem aging process, we investigated the specific role of Prdx6 as a biomarker in beef tenderization. In this study, we determined the changes in myofibrillar protein particle size during postmortem aging to observe myofibrillar protein degradation, and explored the changes in intrinsic differential proteins using tandem mass tag (TMT)-based quantitative proteomics. The results showed that the degradation of myofibrillar proteins in beef was promoted after incubation with MJ33, an inhibitor of iPLA₂ activity of Prdx6, for 24 h. A total of 336 differential proteins were identified by proteomics analysis in the Con (normal saline) vs G0 (unincubated), MJ33 vs G0, and MJ33 vs Con groups, with the core ones being PRDX6, SOD1, GPX1 and PARK7. These differential proteins were primarily enriched in glycolysis, the apoptosis signaling pathway and cytoskeletal proteins and were predominantly located in the cytoplasm. However, the differential proteins between the MJ33 and Con groups were mainly concentrated in the cell membrane. Interactions existed among some differential proteins, which were mainly enriched in cellular antioxidant defense, ribosome-mediated protein synthesis regulation, and phospholipid functions. It is suggested that inhibiting Prdx6 iPLA₂ activity might impact the degradation of myofibrillar proteins by mediating membrane function, energy metabolism, and apoptosis, ultimately accelerating beef tenderization.

The decay of meat and meat products is primarily attributed to oxidation and microbial contamination during processing and storage. Chitosan, renowned for its remarkable antibacterial and antioxidant properties, has found wide applications in enhancing meat and meat product quality as well as extending their shelf life. Despite this, the antibacterial mechanism of chitosan remains unclear, and there is a dearth of systematic and comprehensive summaries regarding its application in meat and meat products as well as influential factors thereof and its potential synergistic effects with other preservation techniques. Consequently, in order to provide new ideas for the application and research of chitosan in meat and meat products, this article reviews recent progress in the application of chitosan in the meat industry, elucidates its preservation mechanism, systematically analyzes the factors that affect its efficacy in meat and meat products, and summarizes the preservation techniques that can synergistically enhance the efficacy of chitosan.

This study analyzed the effect of vacuum skin packaging (VSP) and high-oxygen modified atmosphere packaging (HiOx-MAP) on the quality changes of pork during chilled storage (0-4 ℃ ), which were evaluated in terms of pH, color, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid reactive substances (TBARS) value, protein carbonyl and sulfhydryl content, total viable count (TVC) and microbial diversity. The results showed that the brightness (L*) and yellowness (b*) values of pork were always higher in the HiOx-MAP group than those in the VSP group during the whole storage period (P < 0.05). Compared with the VSP group, the HiOx-MAP group showed a higher redness (a*) value at the early stage but a significant lower a* value at the late stage of storage (P < 0.05), indicating that the HiOx-MAP group had poor color stability. Furthermore, the HiOx-MAP group had higher TBARS value and lower protein carbonyl and sulfhydryl content (P < 0.05). Additionally, the shelf lives of both groups were 20-25 days, but the TVC of the HiOx-MAP group was significantly higher than that of the VSP group starting from day 10 (P < 0.05). With increasing storage time, the microbial diversity of both groups showed a decreasing trend, but the α diversity in terms of the number of operational taxonomic units (OTU), Chao1 index and Shannon index of the HiOx-MAP group was higher, indicating more abundant microbial species and diversity compared with the VSP group. When the TVC was close to the upper limit of the national standard, the dominant bacteria in the HiOx-MAP group were Leuconostoc, Serratia and Pseudomonas, while Carnobacterium was the dominant bacteria in the VSP group. In conclusion, HiOx-MAP is recommended to maintain better meat color for short-term storage (within 10 days), while VSP can be used for maintaining pork quality and extending the shelf life.

In order to explore the pork spoilage potential of Pseudomonas fragi and the antibacterial mechanism of garlic essential oil, P. fragi was isolated from chilled pork under aerobic storage conditions and tested its spoilage capacity. The isolates with strong spoilage capacity were selected for further investigation. The antibacterial activity of garlic essential oil against the selected strains was evaluated by determining the minimum inhibitory concentration (MIC) and plotting the bacterial growth curve. Furthermore, the antibacterial mechanism was investigated by scanning electron microscopic (SEM) observation as well as measuring cell membrane permeability, bacterial motility and metabolic activity. The results showed that P. fragi could cause pork spoilage. Garlic essential oil exhibited a strong inhibitory effect against P. fragi derived from pork, with a MIC of 0.125 μL/mL. Garlic essential oil could disrupt the normal structural morphology of P. fragi, enhance the permeability of the cell membrane, and inhibit bacterial metabolic activity and mobility. The results from this study can provide a theoretical foundation for the application of garlic essential oil as a natural food preservative.