To investigate the correlation between the beany odor of raw cow’s milk and feed types, this study selected two samples of raw cow’s milk with beany odor and five common feeds: soybean meal, alfalfa, flaked corn, oat grass, and corn silage, and measured their volatile flavor compounds by headspace solid phase microextraction-gas chromatography-mass spectrometry (GC-MS). Key flavor compounds were identified using relative odor activity value (ROAV). The results indicated that acids and aldehydes contributed primarily to the beany odor of raw milk. A total of 49 volatile substances were identified in the two milk samples, among which hexanoic acid, octanoic acid, decanoic acid, decanal, nonanal, (E)-2-octenal, and (E)-2-decenal were the main beany odor substances. A total of 257 volatile substances were detected in all feed samples, including decanal, nonanal, and (E)-2-octenal. According to ROAV analysis, the beany odor compounds were more abundant in the feed samples than in the milk samples. The relative contents of beany odor compounds in the feed samples followed the following decreasing order of alfalfa > oat grass > soybean meal > flaked corn > corn silage, and flaked corn exclusively contained vanillin, with a strong milky aroma.

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.

Human milk oligosaccharides (HMOs) are a group of complex glycans occurring in human breast milk that play important roles in the growth and development of infants. More than 200 distinct kinds of HMOs have been identified so far. The naturally occurring mixtures of HMOs in humans have different components and profiles that reflect the mother’s genetic makeup (e.g., Lewis blood type), duration of lactation, life style, diet and geographic region. A number of functions that may protect the health of breast-fed infants have been reviewed for HMOs. However, available information on the content and profiles of HMOs in human milk, especially among Chinese mothers, is limited. Therefore, further research on the relationship between the structure and functions of HMOs and a databank of HMOs from Chinese mothers are needed in order to establish a firm scientific basis and specific guidelines for improved infant formula in the future.

The contamination of phage is considered as one of the major risks for food fermentation. It may cause the fermentation to slow down or even fail, and then cause huge economic loss. So, understanding the classification, morphology, and infection mechanism of phages and discussing the anti-phage mechanisms of lactic acid bacteria (LAB) are very important to the application of LAB and the production of related products. The aim of this paper is to describe the anti-phage mechanism of LAB, which may provide a certain theoretical support to the selection of anti-phage strains and prevention of phage contamination.

Forty-four strains of Lactobacillus isolated from fermented milk in different regions were identified by using 16S rRNA gene sequencing. The results showed that the species of these Lactobacillus isolates were Lactobacillus casei, Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus helveticus and Lactobacillus bulgaricus. Meanwhile, our present study focused on the susceptibility of these strains to 11 antibiotics from 6 different categories. Our results showed that different Lactobacillus species displayed different resistance to the antibiotics.

With the development of the society and the improvement of living standards, the dairy quality and safety is attracting increasing attention. However, with the extension of the dairy supply chain and the complexion of the participants’ behavior, it is difficult for consumers to get information about the quality and safety of dairy products. As an effective means of dairy quality and safety management, more and more attention has been paid to dairy quality safety traceability system by relevant departments and consumers. This paper is aimed at reviewing the dairy quality and safety situation in our country, expounding the necessity of establishing quality and safety traceability system, analyzing the problems faced by the promotion of system, proposing some ideas on how to build the framework, and put forward some policy suggestions for system construction.

A method for determining urea in milk and milk powder was developed using high performance liquid chromatography with fluorescence detection (HPLC-FLD). Samples were extracted with a mixture of water and ethanol, the supernatant was derivatized with a solution of xanthydrol in acidic condition. The chromatographic separation was performed on a reversed-phase C18 column using a mobile phase consisting of acetonitrile and sodium acetate solution. The derivatized products were separated and tested using a fluorescence detector at λex 213 nm and λem 308 nm. The method showed a good linear relationship in the range of 0.1–10.0 μg/mL, with R2 > 0.999. The spiked recoveries of urea in formula milk powder and liquid milk samples were in the range of 104%–106% and 83.4%–101% with RSD 2.1% –5.7% and 3.2%–4.9%, respectively. The limits of detection (LODs) in formula milk powder and liquid milk were 30 and 12 mg/kg, respectively. This method proved rapid, sensitive, reliable and reproducible.

In this study, sodium alginate and chitosan were used together to embed Streptococcus thermophilus in the presence of galactooligosaccharide (GOS) for the preparation of alginate/chitosan bilayer synbiotic microcapsules. The preparation process and the storage stability and controlled release of the resulting microcapsules were investigated. The bilayer synbiotic microcapsules prepared at a sodium alginate concentration of 2 g/100 mL had desired appearance, particle size and embedding rate and were found to be stable when exposed to simulated gastric fluid; however, complete disintegration of these microcapsules and consequent complete release of Streptococcus thermophilus were observed when the exposure time was up to 150 min. The survival rate of free Streptococcus thermophilus in suspensions with or without added GOS declined greatly after refrigerated storage, only 0.32% on the 13th day for Streptococcus thermophilus suspension in the absence of GOS compared to 14.64% for the presence of GOS. For bilayer synbiotic microcapsules, the bacterial survival rate descended only slightly during the entire storage period regardless of the presence or absence of GOS and remained as high as 93.64% and 87.98%, respectively.