In order to ascertain the influence of dry granulation on the shelf-life and quality of milk tablets, the rate of lipid oxidation in milk tablets prepared with and without dry granulation was measured and the changes in physicochemical and sensory qualities were compared under accelerated oxidation and normal temperature conditions. The results showed that dry granulation slightly accelerated lipid oxidation and significantly increased surface lipid content compared with the directly prepared sample. During accelerated and normal storage, the changes in all other parameters were similar without significances between the two samples. Furthermore, dry granulation had no evident effect on the shelf life of milk tablets.

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.

This research evaluated the stability of vitamins and active components under ultra-low temperature conditions in order to provide a basis to formulate the quality standard for breast milk bank to ensure minimal nutrient loss during storage at ?80 ℃. The results showed that vitamin contents significantly reduced with storage time up to 12 months, yet no significant change was observed in nucleotide contents. After 3 months of storage, the contents of VB2 and VA decreased to 35% and 29% of the original level, respectively, while VC was at undetectable level. Moreover, nicotinic acid at the end of storage dropped to 69% of the fresh breast milk. Considering the existing quality indicators, the quality standard for breast milk bank should be based on breast milk components to be analyzed and fresh breast milk should be used as far as possible to analyze ingredients with poor stability such as vitamins.

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.

This investigation determined the contents of the fat-soluble vitamins A, D and E in human milk samples collected from Hohhot, the capital of North China’s Inner Mongolia region, and analyzed the changing patterns of these vitamins during the lactation period. Nutritional evaluation of maternal breast milk with respect to these fat-soluble vitamins was conducted by the Chinese dietary reference intake (DRI) with the aim of guiding the development of milk powder products for infants. The results showed that the contents of VA and VE were 0.11 and 0.93 mg/100 mL in colostrum, and 0.05 and 0.29 mg/100 mL in mature milk, respectively, while VD content was too low to be detected in colostrum and mature milk. VA and VE contents tended to decline with prolonged lactation. Moreover, it was found that VA was relatively abundant in breast milk from Hohhot, which could meet infants’ nutritional requirements. However, breast milk could not meet VD and VE requirements for infants. As a result, dietary fortification and supplementation of VD and VE are needed for breastfed infants.