This study investigated the effects of ultrasound–assisted immersion freezing (UIF) at different power rates (0, 200, 400, and 600 W) on the changes in beef quality and flavor after braising. The results demonstrated that UIF treatment at 400 W significantly reduced the juice loss (cooking loss decreased from 49.04% to 39.74%) and fat oxidation (TBARS value decreased from 0.32 mg/kg to 0.20 mg/kg) of braised beef. In addition, the tenderness (hardness value decreased from 5601.50 g to 2849.46 g) and color stability of braised beef were improved after UIF treatment. The flavor characteristics of braised beef were characterized using an electronic nose and an electronic tongue. The PCA analysis data showed that the cumulative contribution rates of the first and second principal components were 85% and 93.2%, respectively, with the first principal component accounting for a higher proportion. The UIF–400 W group had the highest concentration for the first principal component, and the differentiation was not significant compared to the control group. The total amino acid values of different power UIF treatment groups were improved compared to the AF treatment group, indicating that UIF can effectively reduce the losses caused by freezing. The results demonstrate that ultrasound–assisted freezing treatment is beneficial in enhancing the tenderness and flavor attributes of beef after braising, providing new insights into the processing of meat products with desirable quality characteristics.

In this study, myofibrillar proteins (MPs) of thawed pork were treated with plasma-activated water (PAW) generated at different times (0, 5, 10, 15, 20, and 25 s) to investigate whether the function of MPs is improved through PAW and the corresponding regulatory mechanism. The results found that PAW treatments increased the surface hydrophobicity and altered the secondary and tertiary structure of MPs. The α-helix content of MPs treated by PAW reduced from 37.3% to 31.25%. In the PAW25s group, the oxidation of MPs was significantly raised, reflected by the higher carbonyl content and lower total sulfhydryl content compared with other groups (p < 0.05). Furthermore, PAW treatments increased the whiteness and improved the strength, immobilized water contents, resilience, chewiness, and adhesiveness of MP gels. The observation of intermolecular forces and microstructure of MP gels presented an increase in ionic bonding, disulfide bonding, and hydrophobic interactions but a decrease in hydrogen bonding in MP gels with PAW treatments, leading to more homogeneous and denser gel structures compared with the control group. In conclusion, PAW, with a short generation time, significantly fixed and enhanced the function of MPs extracted from thawed pork and, to some extent, improved the processing quality of the MPs of thawed pork.

This study investigated the effects of microwave (MW) reheating, water boiling (WB) reheating, and steaming (ST) reheating on the quality attributes (including reheating loss, moisture content, centrifugal loss, water distribution, color, texture, microstructure, flavor, and taste) of pre-cooked braised chicken (PBC), using a non-reheated group as a control (C). The results showed that the ST group demonstrated the lowest reheating loss, and that ST reheating had the least influence on textural characteristics among all the reheating methods. In addition, the results of the scanning electron microscope (SEM) showed that the integrity of the muscle fibers in the ST group was most comparable to the C group. Meanwhile, the aroma of the ST group was similar to that of the other reheating groups, and it exhibited a greater taste intensity. The ST treatment emerges as a viable reheating method for preserving the quality characteristics of PBC.

The present study demonstrates the effects of pH-shifting treatments and magnetic field-assisted pH-shifting treatments on the properties of myofibrillar protein (MP) in frozen meat. The solubility results indicate that the pH-shifting treatments increased the solubility of MP from 16.8% to a maximum of 21.0% (pH 9). The values of surface hydrophobicity and protein particle size distribution indicate that the pH-shifting treatment effectively inhibited protein aggregation through electrostatic interactions. However, under higher pH conditions (pH 10, 11), the treatments assisted by the magnetic field increased the degree of aggregation. The total thiol content and SDS-PAGE results further suggest that the magnetic field-assisted pH-shifting treatment accelerated the formation of covalent bonds among MPs under the alkaline environment. The results of the Differential Scanning Calorimetry (DSC) and protein secondary structure analysis indicate that the magnetic field promoted the unfolding of protein structures in an alkaline environment, markedly reducing the effective pH levels of pH-shifting. Electron paramagnetic resonance (EPR) data indicate that the phenomenon might be associated with the increased concentration of free radicals caused by the magnetic field treatment. In summary, the application of magnetic field-assisted pH-shifting treatments could emerge as a potent and promising strategy to improve the protein properties in frozen meat.

In this study, 43 strains of Staphylococcus spp. and 22 strains of lactic acid bacteria (LAB), isolated from six representative fermented meat products (domestic and international), were subjected to a comprehensive safety evaluation, including hemolytic activity, catalase test, hydrogen sulfide production, and antibiotic susceptibility screening. Nine strains were selected for secondary screening based on safety criteria, fermentation characteristics, and acid and salt tolerance tests. Two optimal strains were identified—Staphylococcus saprophyticus LH-5 and Latilactobacillus sakei OFN-11—demonstrating excellent compatibility and no mutual antagonism. Both strains were non hemolytic, catalase positive, susceptible to some of the antibiotic tested, and did not produce hydrogen sulfide, mucus, or gas. These favorable fermentation characteristics included lipase/protease production, amino acid decarboxylase negativity, and salt and acid tolerance. Application experiments in fermented sausages were analyzed for 55 volatile compounds, related to meaty, fruity, and fatty aroma profiles compared to commercial starter cultures. The formulation including the selected strains exhibited lower acidity than its commercial unterparts while maintaining superior sensory and physicochemical attributes. These findings suggest that the S. saprophyticus LH-5 and L. sakei OFN-11 consortium holds promising potential as a starter culture for fermented meat products, offering technological advantages to become a fermentation agent that meets the preferences of Chinese consumers.