Journal of Dairy Research最新文献

Synbiotic beverages have become a boon for health-conscious people as these beverages can offer a variety of health benefits. The present study aimed to produce a novel synbiotic beverage from browntop millet (Urochloa ramosa, previously Brachiaria ramosa). Lacticaseibacillus rhamnosus was used for the fermentation of the browntop millet. Multi-response methodology optimization was performed, and maximum ferric-reducing antioxidant power (FRAP) concentration, reducing sugar and protein concentration was observed at 757.42 µ mol Fe (II)/ml, 90.38 mg/ml, and 1.31 mg/ml, respectively. The study also observed an excellent cell hydrophobicity (85.7%) of the probiotic strain. Thus, the final product obtained had a DPPH value of 54.89 ± 2.2 %.

This research paper investigated the potential application of essential oils nano-emulsion after characterization as natural preservatives in the dairy sector, by measuring the minimum inhibitory concentration of ginger and clove oil nano-emulsion along with their impact on the sensory properties, starter culture activity and survivability of some foodborne pathogenic and spoilage microorganisms in fortified laboratory-manufactured labneh. The characterized EOs nano-emulsions exhibited significant antimicrobial effect against the tested microorganisms (Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus flavus). S. aureus was completely inhibited in labneh fortified with 0.1 µg/mL clove and ginger nano-emulsion in the first and second weeks of the storage period, respectively. While A. flavus count was reduced by 100 and 35% in labneh fortified with 1 µg/mL clove and ginger nano-emulsion, respectively. Nonetheless, the overall acceptability and flavour of the fortified samples revealed scores that were not significantly different from the control samples (P > 0.05). These results were obtained without interfering with the starter culture activity during processing and storage period. In conclusion, the obtained results open a promising avenue for the EOs nano-emulsions application as safe and natural alternative in the dairy industry.

This study aimed to develop a predictive model to investigate the effect of temperature, pH, NaCl concentration, initial inoculum concentration and time on enterotoxin A (SEA) production by Staphylococcus aureus. Combinations of three levels of temperature (10, 15 and 25°C ), five levels of pH (5.3, 5.5, 6.0, 6.5 and 6.7), five levels of NaCl (0.8, 1.0, 1.5, 2.0 and 2.2%), three levels of inoculum concentration (0, 3 and 5 log CFU/mL) in brain heart infusion (BHI) broth were studied. Colonies were counted and SEA production was assessed at 24 h intervals for up to 240 h. A probabilistic logistic regression model was used to describe the production of SEA by Staphylococcus aureus. SEA production was influenced by all factors, except NaCl concentration. S. aureus produced SEA in all samples at 25°C, while the temperature of 10°C delayed the growth and SEA production of S. aureus at initial contamination levels of 3 log CFU/mL and 5 log CFU/mL and prevented it at 0 log CFU/mL. The model was statistically and experimentally validated, demonstrating a good fit, with a high percentage agreement, Nagelkerke's R² and the Hosmer and Lemeshow test for the SEA production model. The experimental validation confirmed the effectiveness of the models for predicting the probability of SEA production by S. aureus in Minas Frescal cheese.

Perfluorinated compounds (PFCs) are synthetic chemicals commonly used in various industries for their water-, grease-, and stain-repellent properties. These compounds are highly persistent in the environment and can be absorbed by farm animals, subsequently contaminating animal-derived products. This contamination poses a significant health risk to humans who consume these products. Previous studies have identified cow's milk as one of the primary animal products contaminated with PFCs. However, it remains unclear which specific PFCs increase in concentrations over time. In this study, we analysed data on the concentrations of 24 PFCs in cow's milk sourced from a milk processing plant in Taiyuan, Shanxi Province, China, over a three-year period, as provided by the National Agriculture Science Data Centre. Our analysis revealed that perfluoropentanoic acid (PFPeA) and perfluorobutanoic acid (PFBA) were the dominant PFCs that tended to accumulate in cow's milk over time. Consequently, consumers and milk producers should monitor the levels of PFPeA and PFBA in cow's milk to mitigate potential health risks associated with these pollutants.

Blockchain, an emerging technology exhibiting swift growth, significantly bolsters transparency within a given supply chain, enabling secure traceability, backtracking, and info tracing. Blockchain technology holds substantial promise for the dairy sector, offering enhancements unnecessary market intermediaries, thereby broadening access to credit and insurance for farmers, particularly in developing economies Such advancements could lead to more sustainable, efficient, and resilient livestock practices. However, the technology faces challenges, including the need for sophisticated infrastructure, cross-platform software, and skilled personnel with advanced expertise. Divergence in technological capabilities between developed and developing nations may hinder trade and exacerbate disparities. Regulatory barriers could also restrict blockchain's application. Thus, it is imperative to enhance blockchain knowledge among trade authorities and policymakers to facilitate its broader adoption. The objective of this review is to discuss principles of blockchain and proposed future work pathways for its use in the dairy industry.

The objective of this research paper was to assess consumer knowledge, attitudes, and perceptions towards dairy fat. Adult participants completed a web-based survey collected from November 2022 to February 2023, across Mexico, Chile, and Argentina. In total, 1,204 respondents completed the survey. Most respondents were between 18 and 39 years old, female, educated, and employed. For both women (χ² = 13.7, df = 4 p < 0.01) and men (χ² = 26.7, df = 4 p < 0.01), the percentage of people who consume dairy products at least once a day increases with age. However, neither gender nor age affected the consumption of milk, yogurt, butter, cheese, or cream. An effect of country (χ² = 330.2, df = 18 p < 0.01), age (χ² = 69.2, df = 36 p < 0.01), and gender (χ² = 69.2, df = 36 p < 0.01) was observed with respect to the type of milk consumed. In Mexico, whole milk consumption rates were highest, while semi-skimmed milk was favored in Chile, and skimmed milk in Argentina. Whole milk consumption was higher in men, however, skimmed and light milk were preferred by women. An effect of country (χ² = 30.4, df = 14 p < 0.01) and age (χ² = 70.1, df = 28 p < 0.01) was observed in relation to the type of fat that people consider most important. More respondents (48%) considered milk fat to be "healthy" or "very healthy" while no dependence was observed between countries and the relationship between the milk fat content and health. The best-known milk fat component in Argentina was omega-6 while Chilean consumers were less familiar with this component. Mexican consumers, gave greater importance to mono-unsaturated fats. Knowledge of other dairy fat groups and nutrients was similar across countries. This study benchmarks consumer knowledge and perceptions of dairy fat in Latin America, offering valuable insights for academia, industry, and consumers in the dairy sector.

This communication addresses the hypothesis that silver nanoparticles obtained by green synthesis (G-AgNPs), using an aqueous extract of chicory, have antibacterial activity against bovine mastitis-associated strains and may inhibit their adherence capacity. Bovine mastitis is among the diseases with the greatest economic impact worldwide. Multifactorial in nature, it is usually associated with infection caused by bacterial species such as Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis, and Escherichia coli. Antibiotics are currently the main line of treatment, but in order to offset the emergence of resistance, alternative compounds and nanomaterials are being researched for prevention and control. In this study, bacteria that cause bovine mastitis were molecularly identified by groEL gene PCR-RFLP. Then, G-AgNPs were produced using an aqueous extract of chicory as a reducing and stabilizing agent. The nanoparticles showed powerful antibacterial activity, but they did not seem to reduce the adherence of pathogens to MAC-T cells that had been preincubated with a sub-MIC concentration of G-AgNPs. Nevertheless, very low concentrations (21-30 pM) were needed for the antibacterial effect to take place, which makes G-AgNPs promising candidates for the control of bovine mastitis.

Colostrum (CM) and transition milk (TM) are crucial for neonatal development but knowledge about the changes in their composition in dairy goats is still limited. The aim of this study was to characterise the immunological, lipid and microbial changes from CM to TM in Guanzhong dairy goats, an indigenous, highly productive Chinese breed. Milk samples were collected from eight primiparous goats at day 0 (CM) and day 7 (TM) postpartum. Immunoglobulin concentrations (IgG, IgA, IgM) were measured by ELISA, long-chain saturated fatty acids (FA) were analysed by gas chromatography, and bacterial communities were profiled by 16S rRNA gene amplicon sequencing. Microbial functions were inferred using PICRUSt2 (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) software based on KEGG (Kyoto Encyclopedia of Genes and Genomes) orthologs. Immunoglobulin concentrations declined significantly from CM to TM, reflecting a transition from immunoprotection to food supply. The TM had increased concentrations of long-chain saturated FA, particularly palmitic acid (C16:0) and stearic acid (C18:0) and higher concentrations of branched-chain FA, suggesting an adaptation to the growing energy demands of the newborn. Although overall microbial diversity was stable, taxonomic shifts were observed. CM was enriched in Emticicia, which may be involved in oligosaccharide degradation, while TM had higher abundance of Faecalibacterium, Ruminococcus and Salinicoccus, genera associated with SCFA production and intestinal development. Functional predictions indicated enrichment of cold shock and haem biosynthetic pathways in CM and enhanced carbohydrate degradation pathways in TM. Correlation analyses revealed relationships between specific FA and bacterial genera, suggesting interactions between host, microbes and nutrients that may influence milk functionality. This integrative analysis of milk components during early lactation provides new insights into the compositional and functional dynamics of goat milk.

Early pregnancy diagnosis in buffaloes enhances reproductive efficiency and dairy production. This study aimed to develop and validate a duplex TaqMan-based RT-qPCR assay using two interferon-stimulated genes (ISGs), ISG15 and LGALS3BP, for early pregnancy diagnosis in buffaloes. Whole blood samples were collected from artificially inseminated buffaloes before (day 0) and after (days 20, 25 and 40) artificial insemination (AI). On 40 days, post-insemination ultrasonography was performed to categorize animals as pregnant or non-pregnant. RNA from peripheral blood mononuclear cells (PBMCs) was isolated and converted into cDNA. A duplex TaqMan-based RT-qPCR assay was developed to predict pregnancy based on the expression of ISG15 and LGALS3BP in PBMCs. Gene expression was evaluated in a test dataset at various time points. The assay's performance was validated using two additional datasets, under which blood samples were collected randomly at 20 ± 2 days to evaluate its utility for predicting pregnancy. Colour Doppler ultrasonography was utilized to confirm pregnancy at 40 days post-insemination for all the animals. Significantly different abundance of transcripts of ISG15 and LGALS3BP, in pregnant buffaloes, was observed on day 20 post-insemination. A statistically significant fold change (p < 0.05) of ISG15 and LGALS3BP transcripts was observed between pregnant and non-pregnant buffaloes. The receiver operating characteristic curve of validation datasets demonstrated the AUC = 0.95 and AUC = 0.90. The negative predictive value and positive predictive value range from 90% to 95% and 75% to 85%. In conclusion, the developed duplex RT-qPCR-based assay demonstrates high sensitivity and specificity in detecting early pregnancy in buffaloes.

This study examined the effects of fat content (0.1%, 1.5%, 3%, and 3.5%), heat treatment (pasteurization and UHT), and vitamin D supplementation on the physicochemical, microbiological, and sensory characteristics of yoghurt over 21 days. Yoghurts with higher fat content generally received higher sensory acceptability scores (7-8), exhibited less syneresis (14.75-22.48%) and higher whiteness index; 0.1%-fat had the highest syneresis (51.28%) and lowest whiteness (80.77) (p < 0.05). Although pasteurised yoghurt exhibited slightly better firmness (1.77 N) than UHT (1.61 N), no significant effect of heat treatment was found (p > 0.05). Sensory preference was for 3% and 3.5%-fat and pasteurised variety, especially for consistency. All yoghurts maintained viable lactic acid bacteria counts >10⁷ cfu/g throughout the storage period. The vitamin D addition resulted in a 6% average higher syneresis rate (p > 0.05) and a nearly 4% higher whiteness index (p < 0.05). This study shows that it is possible to obtain yoghurts with enhanced properties by optimizing the fat content and heat treatment conditions applied, and it also directs future studies on the effect of vitamin D addition on yoghurt properties.