In recent years, it has been often reported that non-nominal ingredients are found in milks from minor dairy species. Adulteration detection in milks from minor dairy species provides important technical support for market surveillance. DNA-based detection is a common and effective approach for food authentication, and also has advantages in milk adulteration detection. In order to provide a reference for the quality control of minor species milks, this article reviews the general aspects of minor species milks and the application of common DNA-based qualitative and quantitative techniques in adulteration detection in minor species milks in term of target gene selection, and their principles, sensitivities, application scenarios, advantages and limitations.

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.

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.