The aim of this study was to explore the potential of commercial lactic acid bacteria (LAB) as probiotic starters in fermented sausages. We initially investigated the growth activity, acid production capability, and tolerance to fermentation conditions of Lactobacillus sakei, Lactiplantibacillus plantarum, and Pediococcus pentosaceus. All three LAB strains proved viable as starters for fermented sausages. Subsequently, we explored their potential as probiotics based on their antibacterial and antioxidant capabilities. L. plantarum exhibited stronger inhibition against Escherichia coli and Staphylococcus aureus. All three strains displayed antioxidant abilities, with cell-free supernatants showing a higher antioxidant activity compared to intact cells and cell-free extracts. Moreover, the activities of superoxide dismutase, glutathione peroxidase, and catalase were stronger in the cell-free supernatant, cell-free extract, and intact cell, respectively. Finally, we individually and collectively inoculated these three LAB strains into sausages to investigate their impact on quality during the fermentation process. External starters significantly reduced pH, thiobarbituric acid reactive substances, and sodium nitrite levels. The improvements in color and texture had positive effects, with the L. plantarum inoculation achieving higher sensory scores. Overall, all three LAB strains show promise as probiotic fermentation starters in sausage production.

Response surface methodology was used to determine the optimum ratio of rice husk dietary fiber, soybean hull dietary fiber, and inulin as 1.40, 1.42, and 3.24%. The effects of compound and single dietary fiber on water holding capacity, gel strength, secondary structure, rheological properties, chemical action force, and microstructure of myofibrillar proteins (MP) gel were investigated. The application of composite dietary fiber significantly (P < 0.05) improved the gel strength, water holding capacity and storage modulus (G′) of MP gel. Fourier transform infrared spectrum analysis shows that the addition of compound dietary fiber can make the gel structure more stable. The effect of dietary fiber complex on the chemical action of MP gel was further studied, and it was found that hydrophobic interaction and disulfide bond could promote the formation of compound gel. By comparing the microstructure of the MP gel with and without dietary fiber, the results showed that the MP gel with compound dietary fiber had smaller pores and stronger structure. Therefore, the rice hull dietary fiber, the soybean hull dietary fiber and the inulin are compounded and added into the low-fat recombinant meat product in a proper proportion, so that the quality characteristics and the nutritional value of the low-fat recombinant meat product can be effectively improved, the rice hull dietary fiber has the potential of being used as a fat substitute, and a theoretical basis is provided for the development of the functional meat product.

It is inevitable for polyphenols and polysaccharides to interact during food preparation. Modifications in microstructure can lead to changes in the physical and chemical properties of food systems, which in turn may influence the nutritional characteristics and functional activities of the food. Recent studies have shown that, in addition to traditional Chinese medicine compounds, certain natural polysaccharides and polyphenols exhibit significant anti-inflammatory and antioxidant properties. These compounds are also associated with beneficial therapeutic effects for the prevention and treatment of acute lung injury. The objective of this study was to examine the synergistic antioxidant effects of chlorogenic acid (CA) and Lycium barbarum polysaccharide (LBP) in various ratios, along with their combined antioxidant and anti-inflammatory effects on LPS-induced inflammation in rat alveolar macrophages. Using the Combination Index (CI), which quantifies the synergistic or antagonistic effect of two substances, all four combinations showed synergistic antioxidant properties over a range of concentrations by in vitro antioxidant property experiments. However, based on comparing them, the four group ratios exhibited the highest antioxidant activity of the infusion at CA:LBP = 1:7, indicating synergistic interactions (CI < 1). In addition, the antioxidant and anti-inflammatory effects of the CA-LBP complex were observed to alleviate cellular inflammatory injury by reducing LPS-induced nitric oxide and reactive oxygen species production and inhibiting the release of inflammatory factors such as TNF-α and IL-6.

The objective of this study was to investigate the proteomic characteristics for the sarcoplasmic and myofibrillar proteomes of M. longissimus lumborum (LL) and M. psoasmajor (PM) from Small-tailed Han Sheep. During post-mortem storage periods (1, 3, and 5 days), proteome analysis was applied to elucidate sarcoplasmic and myofibrillar protein changes in skeletal muscles with different color stability. Proteomic results revealed that the identified differentially abundant proteins were glycolytic enzymes, energy metabolism enzymes, chaperone proteins, and structural proteins. Through Pearson’s correlation analysis, a few of those identified proteins (Pyruvate kinase, Adenylate kinase isoenzyme 1, Creatine kinase M-type, and Carbonic anhydrase 3) were closely correlated to representative meat color parameters. Besides, bioinformatics analysis of differentially abundant proteins revealed that the proteins mainly participated in glycolysis and energy metabolism pathways. Some of these proteins may have the potential probability to be predictors of meat discoloration during post-mortem storage. Within the insight of proteomics, these results accumulated some basic theoretical understanding of the molecular mechanisms of meat discoloration.

Dry-aged beef has gained interest worldwide in recent years due to its improved sensory attributes. This enhancement is thought to be partially driven by microbial activities, particularly lipolysis and proteolysis. In this study, dry-aged beef manufactured by seven commercial producers in China was analyzed. The pH value and total volatile base nitrogen value of dry-aged beef were determined. High-throughput amplicon sequencing of full-length 16S rRNA genes and internal transcribed spacer (ITS) regions was used to analyze the microbial community. A total of 207 proteolytic and lipolytic isolates were identified by sequencing 16S rRNA genes for bacteria and sequencing the D1/D2 region of 28S rRNA genes and the ITS region for fungi. The results revealed that the crust harbored greater numbers of bacteria and fungi than the interior. The bacterial community was dominated by Pseudomonas species, which were core members in both the crust and interior, while Brochothrix thermosphacta was identified as a core bacterium exclusively in the crust. The fungal community primarily constituted Candida sake, Kurtzmaniella species, and members of the phylum Chytridiomycota. Proteolytic and lipolytic isolates were mainly identified as Pseudomonas sp., B. thermosphacta, Carnobacterium maltaromaticum, Candida zeylanoides (teleomorph: Kurtzmaniella zeylanoides), C. sake, and Debaryomyces hansenii. Two strains of C. zeylanoides and C. sake exhibiting high proteolytic and lipolytic activities effectively hydrolyzed beef fat, myofibrillar protein, and sarcoplasmic protein. This study characterized the main microorganisms and their enzymatic functions associated with dry-aged beef, highlighting the need to explore their contributions to the sensory attributes of dry-aged beef.

This study aimed to investigate the mechanism underlying the synergistic antimicrobial effect of ferulic acid (FA) and ε-polylysine hydrochloride (PL) on Shewanella putrefaciens (S. putrefaciens) and their application on crayfish (Procambarus clarkii). The treatment with FA and PL exhibited a strong synergistic inhibitory effect against S. putrefaciens. The combination of 1/4 Minimum Inhibitory Concentration (MIC) FA and 1/4 MIC PL was the most effective, damaging the cell structure and inhibiting the growth of S. putrefaciens. Plasma-activated water (PAW) can induce microbial inactivation through physical action. In addition, treatments with FA, PL, PAW, PAW-FA, PAW-PL, and PAW + PL-FA substantially decreased total viable counts (TVCs), total volatile base nitrogen (TVB-N), the thiobarbituric acid value (TBA), and the juice loss rate of crayfish, with FA-PL showing the best effect. This study confirmed the antimicrobial efficacy of PL, FA, and PAW, indicating their potential as effective preservatives for controlling spoilage in freshwater crustaceans.