Pasteurization and ultra-high temperature treatment can kill most microorganisms in milk. However, since some bacteria such as Bacillus subtilis can resist pasteurization and ultra-high temperature treatments, even the most stringent heat treatments used to eliminate pathogenic microorganisms in the dairy industry cannot completely inactivate all microorganisms. In addition, highly heat-resistant spores can survive ultra-high temperature processing, so sterilized milk may be contaminated, causing bacterial spoilage in milk and dairy products during storage. In this review, the harms of Bacillus subtilis and its spores, spoilage-causing enzymes and biofilm to sterilized milk and the control measures for them are summarized so as to provide strategies for the prevention and control of Bacillus subtilis in sterilized milk and the quality assurance of milk and dairy products.

Bacillus subtilis has a wide range of applications in the agriculture, industry, medicine and healthcare sectors due to its wide distribution and harmlessness to the environment. In recent years, Bacillus subtilis has been explored worldwide and applied as a new biological bacteriostatic agent, but the application of antibacterial substances secreted by it is still at a theoretical stage. This paper reviews the classification, mechanism of action, possible future applications and extraction optimization of antibacterial substances from Bacillus subtilis. The production of high-dose and high-purity bacteriostatic substances from Bacillus subtilis is an urgent problem to solved before the wide application of them in food preservation and sterilization technologies. This makes it necessary to find ways to improve the purity and yield of bacteriostatic substances. The review concludes with possible directions for future exploration of bacteriostatic substances.

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.

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.

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.