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.