The effects of Alcalase (AT), Protamex (PT) or Flavorzyme (FT) treatment on the antigenicity and molecular mass distribution of proteins, flavor and color of skim milk were investigated by using various techniques such as indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and Tricine-sodium dodecyl sulphate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE). The results showed that the effect of AT treatment on reducing the antigenicity of the major milk allergens was significantly better than that of PT and FT treatment (P < 0.05). The antigenicity of α-lactalbumin (α-LA), β-lactoglobulin (β-LG) and casein (CN) was inhibited by 64.01%, 76.00% and 69.10% by AT treatment for 20 min at an enzyme/substrate ratio of 500 U/g, respectively. The amount of low molecular mass peptides in skim milk increased significantly after treatment with each of the three enzymes. The bitterness, astringency, aftertaste of bitterness (aftertaste-B) and aftertaste of astringency (aftertaste-A) increased with increasing enzymatic treatment time and with increasing enzyme/substrate ratio. The taste of FT-treated milk was better than that of AT- or PT-treated milk. The brightness value of milk decreased significantly, while the redness value increased significantly after enzymatic treatment (P < 0.05). The transmittance increased as well. The color of skim milk treated by AT was more similar to that of whole milk.

Donkey milk is considered as an ideal substitute for human milk because of its high contents of whey protein, lactose, lysozyme, unsaturated fatty acids and vitamin C, and low contents of casein and fat. Additionally, donkey milk has various physiological functions, including hypoallergenic, bacteriostatic and anticancer activity. Thus, this review introduces readers to the nutritional composition of donkey milk, including proteins, amino acids, fats, minerals, vitamins., and compares it with that of human milk, bovine milk, buffalo milk, goat milk, and camel milk, in order to provide useful information for the comprehensive processing and utilization of donkey milk.

Bovine milk contains 2%–5% lipids, secreted by breast epithelial cells and dispersed in the milk in the form of milk fat globules. Most of the milk fat (about 98%) exists in the milk fat globules in the form of glycerolipids, and the rest (about 2%) is polar lipids, including glycerophospholipids, sphingolipids, glycolipids, mainly distributed in the milk fat globule membrane surface. Despite their relative scarcity, milk polar lipids play an indispensable role in the growth and development of mammals. This review introduces readers to the types of polar lipids in milk, and compares the types and quantities of milk polar lipids from different milk sources including cows, buffalo, yak, sheep, goats, donkeys, camels, and humans. Next, this review summarizes the physiological functions of milk polar lipids including inhibition of neutral fat absorption, regulation of intestinal microbial community composition, prevention of cardiovascular disease, prevention of non-alcoholic fatty liver, promotion of cognitive function and nervous system development, and anti-inflammatory effects with a view to providing reference for the research and development of functional milk fat products.

In order to clarify the differences in bovine milk fat globular membrane proteins during different lactation periods, milk fat globular membrane proteins in bovine colostrum and mature milk were characterized by quantitative proteomics. The differentially abundant proteins between the two groups were identified and analyzed by bioinformatics. A total of 763 proteins were identified in this study, of which 197 were shared by the two groups. Meanwhile, 80 differentially abundant proteins were further identified, of which, 41 were up-regulated while the rest were down-regulated (bovine colostrum/mature milk). Bioinformatics analysis of the differentially abundant proteins demonstrated that the main cellular components involving these proteins were exosomes, extracellular space, and extracellular regions. The main metabolic pathways involving them were metabolic pathways, purine metabolism, phenylalanine metabolism, tyrosine metabolism, pyruvate metabolism, and glycolysis/gluconeogenesis. Furthermore, 31 key proteins that could interact with other proteins were identified, including haptoglobin and 2-phospho-D-glycerol acid hydrolase. These findings will help to understand the changes of milk protein composition and its functionality during lactation, and lay the foundation for the deep processing of bovine dairy products.

To elucidate the differential milk fat globule membrane (MFGM) proteins between donkey colostrum (DC) and mature milk (DM), a comparative analysis was performed using proteomics. A total of 216 and 215 MFGM proteins were characterized in DC and DM, respectively. Among them, 15 differentially expressed and 25 specifically expressed MFGM proteins were identified. Bioinformatics analysis showed that the significantly differentially expressed MFGM proteins were mainly involved in cellular components including extracellular exosome, extracellular vesicle, and extracellular organelle compartments, and participated in biological processes such as external stimuli, cell proliferation, and blood vessel morphogenesis, and molecular functions such as metal ion binding, cation binding, and calcium ion binding. Additionally, these significantly differentially expressed MFGM proteins were mainly involved in metabolic pathways such as the complement and coagulation cascades and intestinal immune network for IgA production. Furthermore, some key protein factors with high connectivity, as determined by protein network interaction analysis, were identified as differently expressed MFGM proteins. This study provides a better understanding of the biological properties of donkey MFGM proteins and paves the way for future research of MFGM protein nutrition and for the development of formula milk powder.

Fermented sausages, processed through microbial fermentation, have a long history and cultural significance. The fermentation process not only extends shelf life but also enhances flavor, texture, and nutritional value, making them integral to many global food cultures. These products can be classified into two categories based on fermentation methods, microorganisms used, and flavor: Western and Eastern. Western industrially produced sausages (e.g., salami, chorizo, longaniza, and pepperoni) commonly utilize exogenous starter cultures during initial fermentation to ensure product consistency, which create complex flavors like acid, fruity, and smoky. In contrast, Eastern traditional fermented sausages (e.g., Sichuan-style Chinese sausages, Nham, and kimichi sausages) predominantly rely on spontaneous fermentation, with their ingredient formulations and processing techniques profoundly reflecting regional artisanal characteristics. This review explores the production processes, microbial community succession, and their effects on flavor, comparing Western and Eastern fermented sausages in terms of microbial species, fermentation processes, and flavor mechanisms. The findings show that Western products tend to have more concentrated microbial roles and more complex flavors. The characteristic flavor profiles of Eastern fermented sausages primarily derive from region-specific ingredients (e.g., Sichuan pepper, glutinous rice, and kimchi), while their low standardization in production processes results in remarkable regional variations. As globalization advances, the international production and consumption of fermented sausages increase, and optimizing microbial selection and fermentation environments will be crucial to enhancing flavor, nutritional value, and food safety to meet the diverse needs of consumers worldwide.

In this study, the bioinformatics software DNAStar and Geneious and multiple reaction monitoring mass spectrometry (MRM-MS) were used to predict the linear epitope parameters, secondary structure content and epitope regions of bovine whey proteins. Meanwhile, relative quantification of linear allergenic epitopes was carried out. The results indicated that α-lactalbumin (α-LA) and β-lactoglobulin (β-LG) had 7 and 10 linear epitope regions, respectively. The secondary structure of α-LA and β-LG mainly consisted of α-helix, followed by β-turn, β-sheet and random curling, indicating that the structure of α-LA and β-LG made them more likely to become epitopes. Alkaline, protamex and flavourzyme treatment effectively reduced the linear allergenic epitopes of α-LA and β-LG by 50.0%-80.0%, with this effect being more pronounced for β-LG. The relative quantitation results showed that the content of 95.0% of linear epitope peptides was significantly reduced.

This study investigated the effects of a xylitol-casein non-covalent complex (XC) on parameters related to type 2 diabetes mellitus (T2DM), in addition to related changes in gut microbiome composition and functions. High-fat-diet (HFD) + streptozotocin (STZ)-induced T2DM mice were treated with xylitol (XY), casein (CN), and XC, after which fecal samples were collected for gut microbiota composition and diversity analyses based on 16S rRNA high-throughput sequencing and multivariate statistics. XC decreased body weight and improved glucose tolerance, insulin sensitivity, pancreas impairment, blood lipid levels, and liver function in T2DM mice compared to XY- and CN-treated mice. Furthermore, XC modulated the α-diversity, β-diversity and gut microbiota composition. Based on Spearman’s correlation analysis, the relative abundances of Alistipes, Bacteroides, and Faecalibaculum were positively correlated and those of Akkermansia, Lactobacillus, Bifi dobacterium, and Turicibacter were negatively correlated with the phenotypes related to the improvement of T2DM. In conclusion, we found that XC alleviated insulin resistance by restoring the gut microbiota of T2DM mice. Our results provide strong evidence for the beneficial effects of XC on T2DM and motivation for further investigation in animal models and, eventually, human trials.

Yogurt is highly sought after by consumers because of its unique flavor, rich nutritional value and health care function. However, during its sale and storage, some undesirable phenomena such as unstable gel structure and whey precipitation are prone to occur, which has affected the further development of yogurt industry to some extent. Polysaccharides and proteins act as typical thickeners and stabilizers in food, enhancing the structural stability of yogurt gel through different mechanisms. Anionic polysaccharides interact with casein electrostatically to form complexes, while neutral polysaccharides rely on their hydration capacity and act as fillers to stabilise the three-dimensional structure of yogurt. Milk proteins and vegetable proteins play a stabilising role mainly through hydrophobic interactions and disulphide bonds. Gelatin, on the other hand, relies on its good hydration capacity and gelation properties. Polysaccharide and protein complexes mainly rely on non-covalent interactions to stabilise the yogurt gel structure. This paper reviewed the mechanisms of yogurt gel formation and the factors that affect yogurt texture. It also summarized the research progress on enhancing the structural stability of yogurt gel using polysaccharides and proteins as well as their complexes as additives, with a view to providing theoretical bases for improvement of the textural properties of yogurt.

Donkey milk has a variety of physiological functions, including antibacterial and anti-inflammatory. Donkey whey proteins (DWPs), as the main functional component in donkey milk, its inhibitory effect on colitis is still unclear. In this study, the inhibitory effect and potential mechanism of DWPs on dextran sulfate sodium (DSS)-induced colitis were investigated. Firstly, the DWPs and bovine milk whey proteins (BWPs) were characterized using proteomics. Then, we administered DWPs and BWPs to mice with colitis via oral gavage. The results of immunohistochemistry and flow cytometry indicated that DWPs increased T regulatory cell accumulation and increased the abundance of the cluster of differentiation 205⁺ (CD205⁺) macrophages compared to those with BWPs and in model groups. In addition, DWPs exhibited a more remarkable ability to inhibit pro-inflammatory proteins (S100A8, TRAF6, and NF-κB) expression and inflammatory secretion than BWPs. In addition, DWPs significantly decreased NF-κB and CD86 levels more than BWPs or the negative control in both LPS-stimulated human peripheral blood mononuclear cells or cell lines. These findings indicate that DWPs comprise a promising anti-colitis functional food, and this work has established a foundation for future research on these compounds.