China is blessed with minor species milk resources. Minor species milks from different sources have their own distinctive characteristics in terms of nutrient composition and content as well as functional activity. Oligosaccharides, as important bioactive ingredients in milk, have many significant biological functions. With the aim of providing theoretical reference for the development and utilization of oligosaccharides in minor species milk, this paper reviews recent progress in the research on the types, structures and contents of oligosaccharides in goat milk, donkey milk, buffalo milk, camel milk and horse milk, and it also summarizes the bioactive functions of milk oligosaccharides such as probiotic, antibacterial and anti-inflammatory properties as well as promoting brain development.

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.

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.

In this study, the effect of dual-enzyme hydrolysis on the allergenicity of the major proteins in skimmed milk was evaluated based on the degree of hydrolysis, molecular mass distribution, immunoglobulin G (IgG) binding capacity and allergic patients’ serum IgE binding capacity of hydrolysates. The results showed that after one-step hydrolysis for 80 min at an enzyme/substrate ratio of 3 000 U/g and an Alcalase to Flavourzyme ratio of 3:1, the IgG binding capacity of casein, α-lactalbumin and β-lactoglobulinin in skimmed milk decreased significantly by 74.93%, 97.24% and 93.46%, respectively (P < 0.05).The advanced structure of proteins was damaged, leading to an increase in the α-helical and β-turn contents, and a decrease in the β-sheet content. In addition, the free sulfhydryl content increased significantly to 14.29 μmol/g (P < 0.05), the surface hydrophobicity also increased, and the structure became loose. The particles in skimmed milk were aggregated, causing the average particle size to increase significantly to 346.90 nm (P < 0.05) and reducing the stability of skimmed milk. The binding capacity to serum IgE from patients with milk allergy of the enzymatic hydrolysate decreased significantly by 23.53% (P < 0.05), and the overall allergenicity decreased significantly by 69.60% (P < 0.05). Therefore, dual-enzyme hydrolysis is an effective method to reduce the allergenicity of skimmed milk.

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.

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.

Bovine milk is considered as the raw milk of choice for the production of infant formula. Amino acids in bovine milk, the structural units that make up milk proteins are classified into two groups: free and insoluble-proteome amino acids, which are distributed in different regions (structural domains). In this experiment, we collected bovine colostrum at 0–7 days postpartum and mature milk at 15 days-6 months postpartum for comparative analysis of the insoluble-proteome and free amino acids in them. The results indicated that 9 essential free amino acids and 7 non-essential free amino acids were detected in both milks. Additionally, another non-essential free amino acid was found in bovine colostrum. Among these, 8 essential and 4 non-essential amino acids were found to be significantly more abundant in bovine colostrum than in mature milk (P < 0.05). Among the insoluble-proteome amino acids, 8 essential amino acids and 10 non-essential amino acids were detected simultaneously in both milks. Moreover, the levels of threonine, arginine, serine, cysteine, alanine in bovine colostrum were significantly higher than in mature milk (P < 0.05), while the level of lysine was significantly lower than in mature milk (P < 0.05).

The secondary structure of whey proteins in donkey and bovine milk were investigated by Fourier transform infrared spectroscopy (FTIR), and comparative functional evaluation was carried out by gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results showed that there were differences in the secondary structure of whey proteins between donkey and bovine milk. As the lactation period proceeded, the secondary structure content of whey proteins in both milks changed. Whey proteins in donkey colostrum and milk were involved in more biological functions and metabolic pathways compared with those in bovine colostrum and milk, especially in donkey milk, which could thus be more beneficial to the development and utilization of infant formula milk powder.

In order to explore the inhibitory effect of bioactive substances on the degradation of milk fat during simulated gastrointestinal digestion, the impact of bioactive substances on the in vitro digestibility of milk proteins was examined as well as the inhibitory effect on pancreatic lipase activity and the micellar solubility of cholesterol. The results showed that the in vitro digestibility of milk proteins was inversely proportional to the concentration of the tested bioactive compounds, which decreased from 90.94% to 68.37% and 86.00% with increasing concentration of epigallocatechin (EGC) and β-glucan, respectively. The inhibitory effect of EGC on pancreatic lipase activity decreased to different extents with increased amount of added milk proteins, and so did the inhibitory effect of β-glucan and a mixed solution of 2.5 g/L β-glucan, 3.0 g/L epigallocatechin gallate (EGCG) and 2.0 g/L EGC on the micellar solubility of cholesterol. The inhibitory effect of this mixture on the degradation of milk fat was stronger than that of β-glucan.

In recent years, significant breakthroughs in intestinal flora research have suggested that Bacteroides ovatus has the ability to metabolize polysaccharides and choline salts, exerting therapeutic effects on diabetes, cardiovascular disease, inflammatory bowel disease and cancer as well as other physiological functions that make it a promising potential next generation probiotic. It has been of great interest to researchers worldwide. This article presents a systematic and comprehensive review of the bacteriological characteristics, functional characteristics and application prospects of Bacteroides ovatus, which is still in the literature. We expect to provide valuable information for researchers interested in Bacteroides ovatus and its application.

Pasteurized milk is favored by consumers worldwide because of its mild sterilization conditions, which can not only kill most pathogenic bacteria in raw milk but also maintain the main nutrients and flavor of fresh milk to the maximum extent. However, because low-temperature sterilization cannot completely inactivate all microorganisms in raw milk, some microorganisms remain in the final product and cause spoilage, which restricts the production, sale and consumption of pasteurized milk. The traditional method of detecting dairy quality is simple and rough. Therefore, this paper reviews the recent progress in the determination of the nutritional and microbial quality of pasteurized milk and other dairy products, in order to provide a theoretical basis for improving product quality and optimizing processing conditions.

Dairy products are an important part of the dietary structure of Chinese residents. A wide variety of dairy products are commercially available, which are rich in nutrients and contain high-quality protein, various trace elements and functional ingredients including such active ingredients that are beneficial for lipid metabolism as milk calcium, whey, polar lipids and conjugated linoleic acid. Dairy products have the potential to regulate blood lipids and reduce the risk of cardiovascular disease. In addition, dairy products are high-quality carriers of active ingredients, and the active ingredients in milk can synergize with those added to milk to regulate blood lipids or to protect them. For this reason, milk is often used as an ingredient of functional dairy products. Hyperlipidemia is recognized worldwide as one of the risk factors for cardiovascular and cerebrovascular diseases such as atherosclerosis, coronary heart disease and hypertension. Studies have shown that functional milk can aid in regulating blood lipids. This paper reviews the current status of studies on dairy products and lipid metabolism-related health problems, aiming to provide a theoretical basis for the research of functional dairy products.

In order to understand the influence of interaction between the functional components and milk proteins in lipidlowering milk on the effectiveness of the functional components, we investigated the influence of casein and whey protein on the inhibitory effect of epigallocatechin (EGC) against pancreatic lipase, and we also determined the influence on the antioxidant activity of a mixture of EGC and the functional components as well as the influence on the inhibitory effect of a mixture of β-glucan and the functional components on the solubility of cholesterol-containing micelles. The results showed that milk protein could reduce the inhibitory effect of the functional components on pancreatic lipase activity, and decrease their antioxidant activity and their ability to inhibit the solubility of cholesterol-containing micelles.

Milk is not only rich in various nutrients, but also contains bioactive substances which have been documented to exert protective effects in the human body. Milk glycoproteins play a role in protecting against pathogen infection, modulating the intestinal flora and regulating the immune system. This paper summarizes the types of protein glycosylation and the methods used to study protein glycosylation and reviews milk glycoprotein composition, glycosylation sites, glycan structure and bioactive functions of milk glycoproteins, aiming at providing useful information for further study and utilization of these important bioactive glycoproteins.

Lactobacillus plantarum, a member of the lactic acid bacteria family, is widely found in nature, especially in a variety of fermented foods. Since Lactobacillus plantarum is a member of the human intestinal microflora, the health benefits of fermented foods containing this bacterium have made it a model microorganism in genomic, proteomic, transcriptomic and metabonomic studies to clarify microbial environment adaptability and molecular mechanisms underlying probiotic health benefits. This review summarizes the recent advances in understanding the physiological functions and omics of Lactobacillus plantarum, with the aim of providing useful information for researchers.

Breast milk is the best source of food for infants and young children, and the whey proteins contained in the milk are the base of nutritional and bioactive substances including bioactive peptides, which play an important role in promoting human health. In this research, the antioxidant activities of peptides prepared by enzymatic hydrolysis of breast milk whey proteins with four different proteases, i.e., neutral protease, alkaline protease, papain and trypsin, were assessed and compared. The hydrolysis conditions were optimized using combination of one-factor-at-a-time method and response surface methodology. Neutral protease was found to be the most suitable enzyme for the production of antioxidant peptides from breast milk whey proteins. The optimal hydrolysis conditions were established as follows: pH 7.21, 50.03 ℃, an enzyme/ substrate ratio of 4 486.68 U/g and 5 h. The effect of hydrolysis parameters on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was in the decreasing order: enzyme/substrate (E/S) ratio > temperature > initial pH. Fraction I with the highest antioxidant activity was separated chromatographically with macroporous resin, Sephadex G-25 and Sephadex G-15, which could scavenge 60.31% of DPPH radical.

Milk protein is the most important nutrient in the initial stage of life, and it is abundant in kind and quantity. The composition of milk proteins has been made more complex and tremendously increased through a large number of genetic variations and sufficient protein translation. Proteomics permits one to systematically and integrally study milk proteins to understand the ways milk proteins constitute and regulate some life activities and further obtain a comprehensive and in-depth understanding of the expression levels of milk proteins. This paper describes the main techniques used in proteomics studies, including two dimensional electrophoresis, high performance liquid chromatography (HPLC), isobaric tags for relative and absolute quantitation (iTRAQ), mass spectrometry and bioinformatics techniques. The applications of proteomics in studies on human and bovine milk in particular differential proteomics analysis are discussed. To conclude, proteomics allows a better understanding of human and bovine milk which can provide a theoretical basis for developing infant foods and dairy products.

In this study, proteins from human and bovine milk fat globule membranes were separated using SDS-PAGE and identified by liquid chromatography-mass spectrometry (LC-MS). It was found that 1 076 proteins from human milk fat globule membrane were identified, and 682 proteins from bovine milk fat globule membrane. Among these proteins, 757 specifically expressed proteins were derived from human milk fat globule membrane, and 363 specifically expressed proteins from bovine fat globule membrane, with 319 of these being common to both. According to gene ontology (GO) annotations analysis, human milk fat globule membrane proteins played a more significant role in biological process than did bovine milk fat globule membrane proteins, especially in cellular component organization. The molecular function of human milk fat globule membrane proteins was exerted mainly through binding. In cellular composition, human milk fat globule membrane proteins were more dominant than bovine milk fat globule membrane proteins, and mostly participated in intracellular components. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that there were 15 human milk fat globule membrane proteins involved in the digestion and absorption related KEGG pathway—enzymatic glycolysis. The study of human milk fat globule membrane proteins can improve the accuracy of milk fat globule membrane protein utilization, and the experimental data obtained may provide theoretical reference for future development of functional foods for infants.

SDS-PAGE was used for separating the protein components of milk fat globule membranes (MFGMs) from bovine colostrum and milk, and it was found that the compositions of milk fat globule membrane proteins in colostrum and mature milk were different. A total of 628 MFGMs were identified in bovine colostrum and 487 MFGMs in mature milk. Gene ontology (GO) annotation showed that the main role milk fat globule membranes from bovine colostrum and milk played in biological processes was biological regulation. With respect to molecular function, bovine colostrum fat globule membrane proteins had greater binding capacity than mature milk fat globule membrane proteins, and the former was found to exist much more abundantly in extracellular areas than the latter. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that both membrane proteins participated in different metabolic pathways, implicating that bovine colostrum can be further processed into high-quality products.

In this study, the whey proteins in human and bovine colostrum were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and identified by liquid chromatography-mass spectrometry (LC-MS). A total of 477 whey proteins were identified in human colostrum and 325 in bovine colostrum. Totally, 343 proteins were specifically expressed in human colostrum and 191 in bovine colostum. Moreover, 134 specifically expressed proteins were common to both. Gene ontology (GO) annotation analysis revealed that human colostrum whey proteins played a more important role in bioprocesses especially stress responses than their bovine counterparts. Human colostrum whey proteins exerted functions by binding to other molecules. Human colostrum whey proteins were more important constituents of cellular structures as compared with their bovine counterparts, and they were the most significant constituents of extracellular structures. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, 23 whey proteins in human colostrum were involved in the KEGG pathway related to digestion and absorption, enzymatic glycolysis.