Genetic relationship of energy balance predicted from milk traits with fertility in Japanese Holsteins.

We predicted the energy balance of cows from milk traits and estimated the genetic correlations of predicted energy balance (PEB) with fertility traits for the first three lactations. Data included 9,646,606 test-day records of 576,555 Holstein cows in Japan from 2015 to 2019. Genetic parameters were estimated with a multiple-trait model in which the records among lactation stages and parities were treated as separate traits. Fertility traits were conception rate at first insemination (CR), number of inseminations (NI), and days open (DO). Heritability estimates of PEB were 0.28-0.35 (first lactation), 0.15-0.29 (second), and 0.09-0.23 (third). Estimated genetic correlations among lactation stages were 0.85-1.00 (first lactation), 0.73-1.00 (second), and 0.64-1.00 (third). Estimated genetic correlations among parities were 0.82-0.96 (between first and second), 0.97-0.99 (second and third), and 0.69-0.92 (first and third). Estimated genetic correlations of PEB in early lactation with fertility were 0.04 to 0.19 for CR, -0.03 to -0.19 for NI, and -0.01 to -0.24 for DO. Genetic improvement of PEB is possible. Lower PEB in early lactation was associated with worse fertility, suggesting that improving PEB in early lactation may improve reproductive performance.

Isolation, whole genome sequencing and application of a broad-spectrum Salmonella phage.

Salmonella is considered as one of the most common zoonotic /foodborne pathogens in the world. The application of bacteriophages as novel antibacterial agents in food substrates has become an emerging strategy. Bacteriophages have the potential to control Salmonella contamination.We have isolated and characterized a broad-spectrum Salmonella phage, SP154, which can lyse 9 serotypes, including S. Enteritidis, S. Typhimurium, S. Pullorum, S. Arizonae, S. Dublin, S. Cholerasuis, S. Chester, S. 1, 4, [5], 12: i: -, and S. Derby, accounting for 81.9% of 144 isolates. SP154 showed a short latent period (40 min) and a high burst size (with the first rapid burst size at 107 PFUs/cell and the second rapid burst size at approximately 40 PFUs/cell). Furthermore, SP154 activity has higher survival rates across various environmental conditions, including pH 4.0-12.0 and temperatures ranging from 4 to 50 °C for 60 min, making it suitable for diverse food processing and storage applications. Significant reductions in live Salmonella were observed in different foods matrices such as milk and chicken meat, with a decrease of up to 1.9 log10 CFU/mL in milk contamination and a 1 log10 CFU/mL reduction in chicken meat. Whole genome sequencing analysis revealed that SP154 belongs to the genus Ithacavirus, subfamily Humphriesvirinae, within the family Schitoviridae. Phylogenetic analysis based on the terminase large subunit supported this classification, although an alternate tree using the tail spike protein gene suggested affiliation with the genus Kuttervirus, underscoring the limitations of relying on a single gene for phylogenetic inference. Importantly, no virulence or antibiotic resistance genes were detected in SP154. Our research highlights the potential of using SP154 for biocontrol of Salmonella in the food industry.

Flow properties of single origin chocolates: Effect of product formulation and particle size.

The objective of this research was to evaluate changes in flow behavior of chocolate during chocolate grinding using a stone grinder as affected by chocolate formulation. Three different types of chocolates were evaluated. Two chocolates without milk added (70% chocolate) and two chocolates with milk added and with different amounts of cocoa nibs (30% chocolate and 14% chocolate) were tested. For the 70% chocolates, nibs of two different origins were used; therefore, a total of four samples were evaluated. Chocolates were processed in a stone grinder, and samples were taken as a function of grinding time. For each timepoint, the flow behavior of the samples was measured using a rotational rheometer and fitted to the Casson model. Particle size was measured using a laser scattering instrument. Results showed that yield stress increased linearly while the Casson plastic viscosity decreased exponentially with grinding time (smaller particles). Particle size distribution of the chocolates showed a prominent bimodal distribution for short grinding times (∼9 h) with small (∼15 µm) and large (∼100 µm) particles; with longer grinding time, the population of larger particles decreased. Yield stress values were higher for the 70% chocolate, but they were not very different between the two milk chocolates tested. The Casson plastic viscosity was greatest for the 70% chocolate, followed by the 30% chocolate. The 14% chocolate had the lowest Casson plastic viscosity. Changes of Casson plastic viscosity with particle size were more evident for the dark chocolates compared to the milk ones. These results are helpful to small chocolate producers who need better understanding of how the formulation and grinding of chocolate affect its flow behavior, which will ultimately affect chocolate handling during production.

Effect of harvesting strategy of second-cut orchardgrass silage on feed intake, digestion, and milk production in dairy cows.

We investigated the effects of regrowth interval and first-cut timing on the dietary characteristics of second-cut orchardgrass silage and feed intake and milk production in dairy cows fed second-cut orchardgrass silage. The second-cut grasses were harvested 7w after the first-cut at the early stage (E7w) or at the heading stage (H7w), or harvested 6w after the first-cut at the early stage (E6w) from orchardgrass sward, and then ensiled. We evaluated the effect of regrowth interval by comparing E7w and E6w, and the effect of first-cut timing by comparing E7w and H7w. Six multiparous Holstein cows were used in a replicated 3 × 3 Latin square design, with three dietary treatments: diets containing E7w, E6w, or H7w silage at 30% dietary dry matter. We observed that feeding E6w silage instead of E7w silage increased fiber digestibility, dry matter intake, and milk production; however, the first-cut timing (E7w vs. H7w) did not affect nutrient content and digestibility, feed intake, or lactation performance. These results show that harvesting at short regrowth intervals for second-cut orchardgrass can be an effective strategy for improving feed utilization and milk yield; however, the first-cut timing for second-cut orchardgrass has little impact.

A novel ratiometric electrochemical sensing platform combined with molecularly imprinted polymer and Fe-MOF-NH2/CNTs-NH2/MXene composite for efficient detection of ofloxacin.

BACKGROUND: Ofloxacin (OFL) is often abused in medicine and animal husbandry, which poses a great threat to human health and ecological environment. Therefore, it is necessary to establish efficient method to detect OFL. Electrochemical sensor has attracted widespread attention due to the advantages of low cost and fast response. However, most electrochemical sensors usually use one response signal to detect the target, which makes it sensitive to the variable background noise in the complex environment, resulting in low robustness and selectivity. The ratio detection mode and employing molecularly imprinted polymer (MIP) are two strategies to solve these problems. RESULTS: A novel molecular imprinting polymer-ratiometric electrochemical sensor (MIP-RECS) based on Fe-MOF-NH2/CNTs-NH2/MXene composite was prepared for the rapid and sensitive detection of OFL. The positively charged Fe-MOF-NH2 and CNTs-NH2 as interlayer spacers were introduced into the negatively charged MXene through a simple electrostatic self-assembly technique, which effectively prevented the agglomeration of MXene and increased the electrocatalytic activity. A glass carbon electrode was modified by the composite and a MIP film was electropolymerized on it using o-phenylenediamine and ß-cyclodextrin as bifunctional monomers and OFL as template. Then a MIP-RECS was designed by adding dopamine (DA) into the electrolyte solution as internal reference, and OFL was quantified by the response current ratio of OFL to DA. The current ratio and the concentration of OFL displayed a satisfying linear relationship in the range of 0.1 µM-100 µM, with a limit of detection (LOD) of 13.2 nM. SIGNIFICANCE: Combining molecular imprinting strategy and ratio strategy, the MIP-RECS has impressive selectivity compared with the non-imprinted polymer-RECS, and has better repeatability and reproducibility than non-ratiometric sensor. The MIP-RECS has high sensitivity and accuracy, which was applied for the detection of OFL in four different brands of milk and was verified by HPLC method with satisfactory results.

A ratiometric SERS aptasensor based on catalytic hairpin self-assembly mediated cyclic signal amplification strategy for the reliable determination of E. coli O157:H7.

A ratiometric SERS aptasensor based on catalytic hairpin self-assembly (CHA) mediated cyclic signal amplification strategy was developed for the rapid and reliable determination of Escherichia coli O157:H7. The recognition probe was synthesized by modifying magnetic beads with blocked aptamers, and the SERS probe was constructed by functionalizing gold nanoparticles (Au NPs) with hairpin structured DNA and 4-mercaptobenzonitrile (4-MBN). The recognition probe captured E. coli O157:H7 specifically and released the blocker DNA, which activated the CHA reaction on the SERS probe and turned on the SERS signal of 6-carboxyl-x-rhodamine (ROX). Meanwhile, 4-MBN was used as an internal reference to calibrate the matrix interference. Thus, sensitive and reliable determination and quantification of E. coli O157:H7 was established using the ratio of the SERS signal intensities of ROX to 4-MBN. This aptasensor enabled detection of 2.44 × 102 CFU/mL of E. coli O157:H7 in approximately 3 h without pre-culture and DNA extraction. In addition, good reliability and excellent reproducibility were observed for the determination of E. coli O157:H7 in spiked water and milk samples. This study offered a new solution for the design of rapid, sensitive, and reliable SERS aptasensors.

Mammary fat globules as a source of mRNA to model alterations in the expression of some milk component genes during lactation in bovines.

BACKGROUND: The milk's nutritional value is determined by its constituents, including fat, protein, carbohydrates, and minerals. The mammary gland's ability to produce milk is controlled by a complex network of genes. Thereby, the fat, protein, and lactose synthesis must be boost in milk to increase milk production efficiency. This can be accomplished by fusing genetic advancements with proper management practices. Therefore, this study aimed to investigate the association between the Lipoprotein lipase (LPL), kappa casein CSN3, and Glucose transporter 1 (GLUT1) genes expression levels and such milk components as fat, protein, and lactose in different dairy breeds during different stages of lactation. METHODS: To achieve such a purpose, 94 milk samples were collected (72 samples from 36 multiparous black-white and red-white Holstein-Friesian (HF) cows and 22 milk samples from 11 Egyptian buffaloes) during the early and peak lactation stages. The milk samples were utilized for milk analysis and genes expressions analyses using non- invasive approach in obtaining milk fat globules (MFGs) as a source of Ribonucleic acid (RNA). RESULTS: LPL and CSN3 genes expressions levels were found to be significantly higher in Egyptian buffalo than Holstein-Friesian (HF) cows as well as fat and protein percentages. On the other hand, GLUT1 gene expression level was shown to be significantly higher during peak lactation than early lactation. Moreover, lactose % showed a significant difference in peak lactation phase compared to early lactation phase. Also, fat and protein percentages were significantly higher in early lactation period than peak lactation period but lactose% showed the opposite pattern of Egyptian buffalo. CONCLUSION: Total RNA can be successfully obtained from MFGs. The results suggest that these genes play a role in glucose absorption and lactose synthesis in bovine mammary epithelial cells during lactation. Also, these results provide light on the differential expression of these genes among distinct Holstein-Friesian cow breeds and Egyptian buffalo subspecies throughout various lactation phases.

Targeting delivery of miR-146a via IMTP modified milk exosomes exerted cardioprotective effects by inhibiting NF-κB signaling pathway after myocardial ischemia-reperfusion injury.

Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the myocardium. This phenomenon is known as myocardial ischemia-reperfusion injury (MIRI), which includes oxidative stress, inflammation, and further cell death. microRNA-146a (miR-146a) is known to play a significant role in regulating the immune response and inflammation, and has been studied for its potential impact on the improvement of heart function after myocardial injury. However, the delivery of miR-146a to the heart in a specific and efficient manner remains a challenge as extracellular RNAs are unstable and rapidly degraded. Milk exosomes (MEs) have been proposed as ideal delivery platform for miRNA-based therapy as they can protect miRNAs from RNase degradation. In this study, the effects of miR-146a containing MEs (MEs-miR-146a) on improvement of cardiac function were examined in a rat model of MIRI. To enhance the targeting delivery of MEs-miR-146a to the site of myocardial injury, the ischemic myocardium-targeted peptide IMTP was modified onto the surfaces, and whether the modified MEs-miR-146a could exert a better therapeutic role was examined by echocardiography, myocardial injury indicators and the levels of inflammatory factors. Furthermore, the expressions of miR-146a mediated NF-κB signaling pathway-related proteins were detected by western blotting and qRT-PCR to further elucidate its mechanisms. MiR-146 mimics were successfully loaded into the MEs by electroporation at a square wave 1000 V voltage and 0.1 ms pulse duration. MEs-miR-146a can be up-taken by cardiomyocytes and protected the cells from oxygen glucose deprivation/reperfusion induced damage in vitro. Oral administration of MEs-miR-146a decreased myocardial tissue apoptosis and the expression of inflammatory factors and improved cardiac function after MIRI. The miR-146a level in myocardium tissues was significantly increased after the administration IMTP modified MEs-miR-146a, which was higher than that of the MEs-miR-146a group. In addition, intravenous injection of IMTP modified MEs-miR-146a enhanced the targeting to heart, improved cardiac function, reduced myocardial tissue apoptosis and suppressed inflammation after MIRI, which was more effective than the MEs-miR-146a treatment. Moreover, IMTP modified MEs-miR-146a reduced the protein levels of IRAK1, TRAF6 and p-p65. Therefore, IMTP modified MEs-miR-146a exerted their anti-inflammatory effect by inhibiting the IRAK1/TRAF6/NF-κB signaling pathway. Taken together, our findings suggested miR-146a containing MEs may be a promising strategy for the treatment of MIRI with better outcome after modification with ischemic myocardium-targeted peptide, which was expected to be applied in clinical practice in future.

A two-sample Mendelian randomization study of mutual relations of six types of diets in atopic dermatitis.

BACKGROUND: In the continuous endeavor to find safe and efficient treatments for Atopic Dermatitis (AD), there remains a considerable focus on dietary adjustments. Nevertheless, the limited availability of research and conflicting findings in the academic literature pose a hurdle in establishing conclusive recommendations. METHOD: Mendelian randomization (MR) was applied to the most comprehensive genome-wide association studies (GWAS) data on tea intake (447 485), green tea intake (n = 64 949), flavored milk intake (n = 64 941), never eat eggs, dairy, wheat, sugar: Wheat products(n = 461 046), never eat eggs, dairy, wheat, sugar: Sugar or foods/drinks containing sugar (n = 461 046), never eat eggs, dairy, wheat, sugar: I eat all of the above (n = 461 046) and atopic dermatitis (n = 218 467). We used the inverse-variance weighted method (IVW) as the primary method. RESULTS: The IVW analyses have demonstrated an increased tea intake was genetically associated with a reduced risk of AD (odds ratio [OR]: 0.646, 95% confidence interval [CI]: 0.430-0.968, p = 0.034). Furthermore, green tea intake was significantly negatively associated with AD (IVW OR: 0.986, 95% CI: 0.975-0.998; p = 0.024) in the IVW model. AD risk could be reduced by never eating wheat products (IVW OR: 8.243E-04, 95% CI: 7.223E-06-9.408E-02, p = 0.003). There was no association between never eating eggs, dairy, wheat, sugar: Sugar, or foods/drinks containing sugar, I eat all of the above and AD. CONCLUSIONS: Our MR study suggests a causal relationship between tea intake, green tea intake, and the avoidance of eating wheat products with atopic dermatitis. Our findings recommend that preventing and managing atopic dermatitis may be achieved by never eating wheat products while increasing tea and green tea intake.

Employing a magnetic chitosan/molybdenum disulfide nanocomposite for efficiently removing polycyclic aromatic hydrocarbons from milk samples.

This study aimed to develop a highly efficient nanocomposite composed of magnetic chitosan/molybdenum disulfide (CS/MoS2/Fe3O4) for the removal of three polycyclic aromatic hydrocarbons (PAHs)-pyrene, anthracene, and phenanthrene. Novelty was introduced through the innovative synthesis procedure and the utilization of magnetic properties for enhanced adsorption capabilities. Additionally, the greenness of chitosan as a sorbent component was emphasized, highlighting its biodegradability and low environmental impact compared to traditional sorbents. Factors influencing PAH adsorption, such as nanocomposite dosage, initial PAH concentration, pH, and contact time, were systematically investigated and optimized. The results revealed that optimal removal efficiencies were attained at an initial PAH concentration of 150 mg/L, a sorbent dose of 0.045 g, pH 6.0, and a contact time of 150 min. The pseudo-second-order kinetic model exhibited superior fitting to the experimental data, indicating an equilibrium time of approximately 150 min. Moreover, the equilibrium adsorption process followed the Freundlich isotherm model, with kf and n values exceeding 7.91 mg/g and 1.20, respectively. Remarkably, the maximum absorption capacities for phenanthrene, anthracene, and pyrene on the sorbent were determined as 217 mg/g, 204 mg/g, and 222 mg/g, respectively. These findings underscore the significant potential of the CS/MoS2/Fe3O4 nanocomposite for efficiently removing PAHs from milk and other dairy products, thereby contributing to improved food safety and public health.

A retrospective comparison of IgE-mediated cow's milk protein allergy management strategies in pediatric cohorts.

BACKGROUND: Complete avoidance of milk is the usual management for IgE-mediated cow's milk protein allergy (CMPA). A baked milk ladder is a method of dietary advancement therapy in IgE-mediated CMPA in Ireland, while in Spain, avoidance of milk awaiting natural tolerance acquisition through an oral food challenge (OFC) is employed. The aim of this study was to evaluate the use of dietary advancement therapy using a milk ladder compared with complete avoidance of milk for managing IgE-mediated CMPA. METHODS: This is a retrospective chart review of 371 pediatric patients from the population who have been treated for IgE-mediated CMPA between 2011 and 2020, with the milk ladder (Ireland) or complete avoidance followed by an OFC (Spain). The main outcome was the introduction of cow's milk. RESULTS: Milk ladder patients were 3.67 times more likely to succeed in comparison with milk avoidance (p < .001). Anaphylaxis during the treatment period occurred in 34 patients in the milk avoidance groups, while three patients in the milk ladder group experienced anaphylaxis due to accidental exposure to milk (p < .001). Failure to complete treatment was associated with a higher skin prick test in the milk avoidance group and a raised specific IgE in the milk ladder group. CONCLUSION: This is the first study that compares outcomes of dietary advancement therapy to complete avoidance for CMPA management, demonstrating that cow's milk can be successfully and safely reintroduced using dietary advancement therapy using a milk ladder.

Evaluating the effects of temperature and agitation on biofilm formation of bacterial pathogens isolated from raw cow milk.

OBJECTIVES: To study the effect of agitation and temperature on biofilm formation (cell aggregates embedded within a self-produced matrix) by pathogenic bacteria isolated from Raw cow milk (RCM). METHODS: A 40 RCM samples were gathered from eight dairy farms in Riyadh, Saudi Arabia. After bacterial culturing and isolation, gram staining was performed, and all pathogenic, identified using standard criteria established by Food Standards Australia New Zealand (FSANZ), and non-pathogenic bacteria were identified using VITEK-2 and biochemical assays. To evaluate the effects of temperature and agitation on biofilm formation, isolated pathogenic bacteria were incubated for 24 h under the following conditions: 4 °C with no agitation (0 rpm), 15 °C with no agitation, 30 °C with no agitation, 30 °C with 60 rpm agitation, and 30 °C with 120 rpm agitation. Then, biofilms were measured using a crystal violet assay. RESULTS: Of the eight farm sites, three exhibited non-pathogenic bacterial contamination in their raw milk samples. Of the total of 40 raw milk samples, 15/40 (37.5%; from five farms) were contaminated with pathogenic bacteria. Overall, 346 bacteria were isolated from the 40 samples, with 329/346 (95.1%) considered as non-pathogenic and 17/346 (4.9%) as pathogenic. Most of the isolated pathogenic bacteria exhibited a significant (p < 0.01) increase in biofilm formation when grown at 30 °C compared to 4 °C and when grown with 120 rpm agitation compared to 0 rpm. CONCLUSION: Herein, we highlight the practices of consumers in terms of transporting and storing (temperature and agitation) can significantly impact on the growth of pathogens and biofilm formation in RCM.

Age-specific composition of milk microbiota in Tibetan sheep and goats.

This study investigates the dynamic changes in milk nutritional composition and microbial communities in Tibetan sheep and goats during the first 56 days of lactation. Milk samples were systematically collected at five time points (D0, D7, D14, D28, D56) post-delivery. In Tibetan sheep, milk fat, protein, and casein contents were highest on D0, gradually decreased, and stabilized after D14, while lactose and galactose levels showed the opposite trend. Goat milk exhibited similar initial peaks, with significant changes particularly between D0, D7, D14, and D56. 16S rRNA gene sequencing revealed increasing microbial diversity in both species over the lactation period. Principal coordinates analysis identified distinct microbial clusters corresponding to early (D0-D7), transitional (D14-D28), and mature (D56) stages. Core phyla, including Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, dominated the milk microbiota, with significant temporal shifts. Core microbes like Lactobacillus, Leuconostoc, and Streptococcus were common in both species, with species-specific taxa observed (e.g., Pediococcus in sheep, Shewanella in goats). Furthermore, we observed a highly shared core microbiota in sheep and goat milk, including Lactobacillus, Leuconostoc, and Streptococcus. Spearman correlation analysis highlighted significant relationships between specific microbial genera and milk nutrients. For instance, Lactobacillus positively correlated with total solids, non-fat milk solids, protein, and casein, while Mannheimia negatively correlated with protein content. This study underscores the complex interplay between milk composition and microbial dynamics in Tibetan sheep and goats, informing strategies for livestock management and nutritional enhancement. KEY POINTS: • The milk can be classified into three types based on the microbiota composition • The changes of milk microbiota are closely related to the variations in nutrition • Filter out microbiota with species specificity and age specificity in the milk.

Prevalence, antibiogram and molecular characterization of Listeria monocytogenes from ruminants and humans in New Valley and Beheira Governorates, Egypt.

BACKGROUND: Listeriosis is a global health threat to both animals and humans, especially in developing countries. This study was designed to isolate Listeria monocytogenes from faeces; environmental samples; and cow, sheep and goat milk, as well as human stool, to study its molecular characteristics and antibiotic sensitivity in the New Valley and Beheira Governorates, Egypt. The isolation and identification of L. monocytogenes were carried out using traditional culture and biochemical methods, followed by antibiography, genus confirmation of some isolates and detection and sequencing of InlB genes via PCR. RESULTS: Out of 2097 examined samples, the prevalence of L. monocytogenes was 13.4% in animals; the prevalence was 9.2%, 2.4%, 25.4%, 4%, 42.4%, and 6.4% in cattle faeces, cattle milk, sheep faeces, sheep milk, goat faeces, and goat milk, respectively. However, the prevalence of L. monocytogenes was 8.3% in human samples. Both animal and human isolates showed 100% resistance to trimethoprim-sulfamethoxazole, and the isolates showed the highest sensitivity to flumequine (100%), amikacin (99.2%), gentamicin (97.6%), and levofloxacin (94.6%). Multidrug resistance (MDR) was detected in 86.9% of the tested isolates. The 16 S rRNA and inlB genes were detected in 100% of the randomly selected L. monocytogenes isolates. Phylogenetic analysis of three isolates based on the inlB gene showed 100% identity between faecal, milk and human stool isolates. CONCLUSIONS: Faeces and milk are major sources of listeriosis, and the high degree of genetic similarity between animal and human isolates suggests the possibility of zoonotic circulation. The high prevalence of MDR L. monocytogenes in both animal and human samples could negatively impact the success of prevention and treatments for animal and human diseases, thereby imposing serious risks to public health.

Sensitive and High-Throughput Time-Resolved Luminescence Detection of Tetracycline in Milk for Eliminating Background Fluorescence on a Miniaturized Apparatus.

Fluorescence detection has always suffered from high background fluorescence from real samples such as milk. Therefore, cumbersome pretreatments of samples were necessary to remove the fluorescent substances but led to long processing times and low efficiency. Time-resolved luminescence detection is a powerful technique for eliminating short-lived background fluorescence without additional pretreatments. However, the related instruments are usually equipped with high-speed excitation sources and detectors, which are always bulky and expensive. Herein, we developed a low-cost and miniaturized imaging system for high-throughput time-gated luminescence detection. An UV LED array was used to excite multiple samples, the luminescence of which could be detected by a smartphone simultaneously. An analog circuit was designed to synchronize the LED to the mechanical chopper to eliminate the background signals resulting from scattering and short-lived autofluorescence. Compared to other synchronous circuits based on FPGAs and microcontrollers, this analog circuit required no programming and memory. For the first time, high-throughput time-resolved luminescence detection of tetracycline in milk without any separation or enrichment was achieved by utilizing a smartphone as a camera, and the scattered signals and the background fluorescence were eliminated efficiently. The limit of detection reached as low as 53 nM (∼0.024 ppm), lower than the residue limit set by the European Union. This high-throughput time-gated luminescence detection method can be used for quantitative analysis of many real samples with high background fluorescence.

A novel dual-model photoelectrochemical/electrochemical sensor based on Z-scheme TiO2 disks/methylene blue for kanamycin detection.

Herein, a new dual-model photoelectrochemical (PEC)/electrochemical (EC) sensor based on Z-scheme titanium dioxide (TiO2) disk/methylene blue (MB) sensibilization for the detection of kanamycin (Kana) was developed. Metal-organic framework-derived porous TiO2 disks were synthesized and exhibited excellent anodic photocurrent under visible light excitation. Subsequently, amino-labeled double-stranded DNA (dsDNA) was introduced into the modified electrode. Photocurrent was enhanced with MB embedded in dsDNA to form Z-scheme TiO2/MB sensibilization. When the target, Kana, was present, it specifically bound to the aptamer in the dsDNA, leading to the disruption of the dsDNA structure and the release of MB. This release of MB and the increase in target spatial resistance resulted in a significant weakening of PEC signal and a decreased oxidation peak current of MB. The PEC sensor successfully detected Kana in the range of 2-1000 pM with an LOD of 0.17 pM. Meanwhile, the EC sensor for Kana detection showed a linear range of 5-500 pM with an LOD of 1.8 pM. Additionally, the sensor exhibited excellent selectivity, reproducibility, stability, and good recoveries when applied to milk and honey samples. As a result, this method has the potential for application in ensuring food safety through the rapid determination of antibiotics in food.

A sensitive aptasensor mediated by gold nanoparticles/metal organic framework lattice for detection of Pb2+ ion in marine products.

Herein, an enzyme-free fluorescent aptasensor was introduced for the ultrasensitive quantification of lead (Pb2+) ion as a hazardous pollutant of the environment and foodstuffs. A nanocomposite of zeolitic imidazolate frameworks-8 and gold nanoparticles (ZIF-8@AuNPs) was utilized as an efficient quencher of the fluorescence intensity of carboxyfluorescein (FAM) signal reporter. The establishment of a hybrid structure between attached aptamer on ZIF-8@AuNPs nanocomposite, and its FAM-tagged complementary (CP) strand decreased the fluorescence response. The preferential binding between the aptamer and Pb2+ released CP strands, which retrieved the fluorescence signal. The aptasensor could assess Pb2+ in the linear concentration range of 1 pM-1 nM with a detection limit (LOD) of 0.24 pM. Besides, it could quantify Pb2+ in various samples, including fish, shrimp, tap water, milk, and serum samples. The developed aptasensor with the superiorities of easiness, cost-effectiveness, easy-to-operate, and rapidness is promising for controlling marine foodstuff safety.

Foodborne bacteria in milk and milk products along the water buffalo milk chain in Bangladesh.

Controlling foodborne pathogens in buffalo milk is crucial for ensuring food safety. This study estimated the prevalence of nine target genes representing seven critical foodborne bacteria in milk and milk products, and identified factors associated with their presence in buffalo milk chain nodes in Bangladesh. One hundred and forty-three milk samples from bulk tank milk (n = 34), middlemen (n = 37), milk collection centers (n = 37), and milk product shops (n = 35) were collected and analyzed using RT-PCR. Escherichia (E.) coli, represented through yccT genes, was the most prevalent throughout the milk chain (81-97%). Chi-squared tests were performed to identify the potential risk factors associated with the presence of foodborne bacteria encoded for different genes. At the middleman level, the prevalence of E. coli was associated with the Mymensingh, Noakhali, and Bhola districts (P = 0.01). The prevalence of Listeria monocytogenes, represented through inlA genes, and Yersinia (Y.) enterocolitica, represented through yst genes, were the highest at the farm level (65-79%). The prevalence of both bacteria in bulk milk was associated with the Noakhali and Bhola districts (P < 0.05). The prevalence of Y. enterocolitica in bulk milk was also associated with late autumn and spring (P = 0.01) and was higher in buffalo-cow mixed milk than in pure buffalo milk at the milk collection center level (P < 0.01). The gene stx2 encoding for Shiga toxin-producing (STEC) E. coli was detected in 74% of the milk products. At the middleman level, the prevalence of STEC E. coli was associated with the use of cloths or tissues when drying milk containers (P = 0.01). Salmonella enterica, represented through the presence of invA gene, was most commonly detected (14%) at the milk collection center. The use of plastic milk containers was associated with a higher prevalence of Staphylococcus aureus, represented through htrA genes, at milk product shops (P < 0.05). These results suggest that raw milk consumers in Bangladesh are at risk if they purchase and consume unpasteurized milk.

The Aggregated and Micellar Forms of ß-Casein Purified from Donkey and Bovine Milk Present Potential as Carriers for Bioactive Nutritional Compounds.

In recent years, there has been a growing interest in the pure casein fraction of milk protein, particularly ß-casein due to its physicochemical properties as well as its bio- and techno-functional properties. The utilization of self-assembled ß-caseins from bovine origin as nanocarriers for the delivery of nutraceutical compounds or drugs has increased dramatically. Concerning ß-caseins from other milk sources, the use of hypoallergenic donkey ß-caseins as a potential delivery vehicle for nutraceutical hydrophobic compounds is beginning to generate interest. The present review deals with casein micelles models, bovine and donkey ß-casein molecular structures, as well as their physical-chemical properties that account for their exploitation in nutraceutics and pharmaceutics. This review work suggests the possibility of developing delivery systems for hydrophobic bioactive compounds using ß-casein purified from hypoallergenic donkey milk, highlighting the potential of this protein as an innovative and promising vehicle for enhancing the enrichment and bioavailability of various bioactive substances in food products.

Cow-calf contact: a single-herd observational study of AMS yield during the first 100 days in milk.

An increasing number of dairy farmers plan to implement cow-calf contact (CCC) in their herd which necessitates descriptions of the cows` performance in different systems. The aim of the study was to describe (1) Automatic milking system (AMS) milk yield of cows in a CCC system during the first 100 days in milk (DIM) and (2) AMS milk yield before and after cow-calf separation. In a prospective study at a commercial Norwegian dairy farm, we included all calvings from Norwegian Red cows between January 2019 to April 2020. After calving, cow-calf pairs stayed in an individual calving pen during the first 5-6 d before they were moved to the loose housing unit with the remaining herd. Calves had whole-day (24 h/d) and full physical contact to the cows. Cows were milked in an AMS. From 14 individual cows of which one cow calved twice during the study period, we collected daily AMS yields from 15 different lactations, with parities ranging from 1 (n = 6), 2 (n = 5) and 3 (n = 4). Due to the sample size and structure of the data set, we only calculated descriptive statistics from DIM 7-100. All data is shown separately for primiparous and multiparous cows. Mean (± SD) calf age at (fence-line) separation was 52 d ± 14.8 beyond which suckling was prevented. Our data indicates great individual variation in the AMS milk yield. Prior to separation, primiparous cows` AMS yields ranged from 11.0 to 25.9 kg/d while that of multiparous cows ranged from 4.8 to 28.8 kg/d. Once calves were no longer allowed to suckle, the yield increased gradually. During the week after separation, AMS yields ranged from 17.3 to 30.4 kg/d for primiparous cows and 8.7 to 41.8 kg/d for multiparous cows and these yields increased in DIM 93-100 (26.5 to 34.3 and 20.6 to 38.3 kg/d respectively). This study is limited by a low sample size from a single-herd but may provide useful descriptions of AMS milk yield in a whole-day, full contact CCC system during the first 100 days of lactation.