Fermented meat products have a long history in China. These products exhibit a characteristic unique flavor, compact meat quality, clear color, long shelf life and wide variety and are easy to transport. During the processing and storage of fermented meat products, microorganisms are present and exhibit diverse characteristics. Microorganisms can accelerate the degradation of proteins and fats to produce flavor compounds, inhibit the growth and reproduction of heterozygous bacteria, and reduce the content of chemical pollutants. This paper reviews the microbial diversity of Chinese ham, sausage, preserved meat, pressed salted duck, preserved fish and air-dried meat and provides analyses of the microbial compositions of various products. Due to the differences in raw materials, technology, auxiliary materials, and fermentation technology, the microbial species found in various fermented meat products in China are different. However, most fermented meat products in China are subjected to pickling and fermentation, so their microbial compositions also have similarities. Microorganisms in fermented meat products mainly include staphylococci, lactobacilli, micrococci, yeasts, and molds. The study of microbial diversity is of great significance for the formation of quality flavor and the safety control of fermented meat products, and it provides some theoretical reference for the study of fermented meat products in China.

Low-temperature storage has become the most common way for fresh meat storage because of its lower cost and better preservation effect. Traditional low-temperature preservation includes frozen storage and refrigeration storage. The refrigeration storage has a good fresh-keeping effect, but the shelf life is short. Frozen storage has a long shelf life, but it has a great impact on the quality of meat structure and other qualities, and cannot achieve a complete “fresh-keeping” effect. With the development of food processing storage and freezing technology, two new storage methods, ice temperature storage and micro-frozen storage, have attracted more attention. In this paper, the effects of different low-temperature storage methods on the sensory, physicochemical properties, myofibrillar protein oxidation, microstructure, and processing characteristics of fresh beef were studied. The optimal storage methods under different storage requirements were analyzed to reveal the mechanism and efficacy of ice temperature storage and micro-frozen storage technology, as well as the advantages compared with traditional low-temperature refrigeration. It has practical significance for guiding the application of low-temperature storage of fresh meat. Finally, this study concluded that the longest shelf life could be achieved by frozen storage, and the best preservation effect was achieved during the shelf life of ice temperature storage, and the effect of micro-frozen storage on the myofibrillar protein oxidation and microstructure was the best.

Nowadays, intelligent packaging has become very popular. It can quickly detect problems that arise during food production or circulation by monitoring the quality and safety of food. Anthocyanins have attracted widespread attention as a material for manufacturing smart food packaging, as they are sensitive to changes in pH, and small changes in pH can cause changes in the color of anthocyanins. The incorporation of anthocyanins often causes different changes in the properties of the films. The effects of anthocyanins on different properties of the films, including barrier, stability, mechanical properties, antioxidant, antibacterial and pH-sensitive were reviewed. We suggest that anthocyanins have the potential to extend the shelf life and monitor the food’s freshness and quality in intelligent packaging.

Mianning ham, a traditional Chinese dry-cured ham, is protected by national geographical indications. To understand the surface and internal flavor composition and microbial community structure of Mianning ham, solid phase microextraction-gas chromatography (SPME-GC-MS) technology and Illumina high-throughput sequencing were utilized. The results showed that a total of 60 flavor substances were identified in the hams. Forty-nine kinds of flavorings were identified on the surface, including 14 aldehydes, 6 ketones, 10 alcohols, 5 esters, 7 hydrocarbons, 5 acids, and 2 other compounds. Thirty-six kinds of internal flavorings were identified, including 13 aldehydes, 4 ketones, 6 alcohols, 3 esters, 5 hydrocarbons, 4 acids and 1 other type. Decanal (34.91 μg/g) was the most prevalent compound on the surface, followed by n-hexanol (24.99 μg/g), n-hexanal (20.20 μg/g), and n-octyl (16.14 μg/g). n-Hexanal (20.74 μg/g) was the most common compound internally, followed by non-aldehyde (5.70 μg/g), 1-octene-3-alcohol (3.54 μg/g), and inverse-2-octenal (2.77 μg/g). Penicillium lanosum, Penicillium nalgiovense, Debaryomyces hansenii, Staphylococcus equorum, and Erwinia tasmaniensis were isolated from the surfaces of the hams by the traditional culture method. By Illumina high-throughput sequencing, three fungal phyla were identified. Ascomycota was the dominant phylum followed by Basidiomycota. At the genus level, 11 fungi were identified, of which Aspergillus was the dominant fungus, followed by Penicillium and Wallemia. These findings provide fundamental knowledge regarding the microorganisms and flavor compounds in Mianning ham, which will help industrial processors develop effective strategies for standardizing quality parameters.

Fermentation of meat products refers to a series of physical, biological or chemical changes in raw meat that occurs under the actions of enzymes or via microbial fermentation and results in the formation of meat products with special flavours, colours and textures that have a long history in China. These products have a unique fermented flavour, bright colour and longer shelf life than ordinary meat products, and some have proteins that are more easily absorbed by the body due to the fermentation of beneficial bacteria. Flavour development in meat products is a dynamic process. During the processing and storage of fermented meat products, the breakdown of proteins and fats is accelerated due to the addition of different fermenting agents. Moreover, the physicochemical reactions that occur within the meat products and the actions of microorganisms during the fermentation process result in the production of flavour compounds, which will determine the final flavour characteristics of the fermented meat product. This paper reviews the flavour characteristics of Chinese dry-cured hams, sausages, bacon, cured fish and sour meat and analyses the flavour substance composition of various products. Due to the differences in the raw materials, processes, auxiliary materials and fermentation processes of various types of fermented meat products in China (ham, sausage, bacon, etc.), the flavour substances contained in the various types of fermented meat products in China are different from each other. However, most fermented meat products in China are cured and fermented, and therefore, they share similarities in terms of their flavour substance composition. The flavour substances in fermented meat products mainly include alcohols, ketones, aldehydes, acids, phenols and aromatic hydrocarbons. The study of such flavour characteristics is of great significance in fermented meat product quality, and provides certain theoretical references for the study of domestic fermented meat products.

The ruminant gut microbial community has a strong impact on host health and can be altered during diarrhea disease. As an indigenous breed of the Tibetan Plateau, domestic yak displays a high diarrhea rate, but little research has been done to characterize the bacterial microbial structure in diarrheic yaks. In the present study, a total of 30 adult yaks, assigned to diarrhea (case, N = 15) and healthy (control, N = 15) groups, were subjected to gut microbiota profiling using the V3–V4 regions of the 16S rRNA gene. The results showed that the gut microbiome of the case group had a significant decrease in alpha diversity. Additionally, differences in beta diversity were consistently observed for the case and control groups, indicating that the microbial community structure was changed due to diarrhea. Bacterial taxonomic analysis indicated that the Bacteroidetes, Firmicutes, and Proteobacteria were the three most dominant phyla in both groups but different in relative abundance. Especially, the proportion of Proteobacteria in the case group was increased as compared with the control group, whereas Spirochaetota and Firmicutes were significantly decreased. At the genus level, the relative abundance of Escherichia-Shigella and Prevotellaceae_UCG-003 were dramatically increased, whereas that of Treponema, p-2534-18B5_gut_group, and Prevotellaceae_UCG-001 were observably decreased with the effect of diarrhea. Furthermore, based on our linear discriminant analysis (LDA) effect size (LEfSe) results, Alistipes, Solibacillus, Bacteroides, Prevotellaceae_UCG_003, and Bacillus were significantly enriched in the case group, while the other five genera, such as Alloprevotella, RF39, Muribaculaceae, Treponema, and Enterococcus, were the most preponderant in the control group. In conclusion, alterations in gut microbiota community composition were associated with yak diarrhea, differentially represented bacterial species enriched in case animals providing a theoretical basis for establishing a prevention and treatment system for yak diarrhea.