A green, fluorescent probe employing erythrosine-B for tracing the accidental administration of levamisole in milk and plasma samples.

A simple and sensitive fluorescent probe has been developed and optimized to detect the non-intentional administration of levamisole (LVM). LVM is used as an anthelmintic therapy in cows, and hence, its residues appear in the drained milk until 60 hours after administering the drug. Meanwhile, levamisole is known to be an adulterant to cocaine and could be detected in addicts' plasma samples. Owing to its severe side effects, including agranulocytosis, which is lethal in many cases, detection and quantification of LVM in milk and plasma samples are of utmost importance. Therefore, a sensitive and selective analytical method is required for this purpose. This work develops a highly fluorescent probe obtained through the reaction between LVM and erythrosine-B in an acidic medium, where the produced ion pair complex has been measured at 553 nm after excitation at 528 nm. The proposed method provides linearity over the concentration range of 0.5-2.0 µg mL-1 for LVM, with a corresponding detection and quantitation limit of 0.5 and 0.3 µg mL-1. Full validation was performed, permitting the application of the suggested method to perform simple extraction steps. All the applied procedures followed the guidelines offered by green analytical chemistry, where the Green Analytical Procedure Index (GAPI) assessed the greenness of the proposed tool, and the yielded pictograms proved the eco-friendliness of the offered tool.

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.

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.

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.

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.

Grape seed oil in the diet of primiparous Jersey cows before and after parturition: effects on performance, health, rumen environment, and milk quality.

The objective of the study was to determine whether adding grape seed oil (GSO) to the diet of primiparous Jersey breeds during the transition period would improve animal health by measuring effects on the rumen environment, serum biochemistry, oxidative response, and the composition and quality of milk. We used 14 Jersey heifers, weighing an average of 430 kg and 240 days of gestation. The animals were divided into two groups and offered a basal diet, including GSO in the concentrate for the GSO group (dose of 25 mL per animal day) and the same dose of soybean oil (SO) for the control group. The animals were allocated and maintained in a compost barn system, receiving an anionic diet (pre-partum) and a diet for postpartum lactating animals. Dry matter intake (DMI), milk production, serum biochemistry, serum and milk oxidative stability, ruminal fluid and milk fatty acid profile, milk qualitative aspects, and ruminal parameters such as pH, bacterial activity, and protozoan count were evaluated. The addition of GSO had a positive effect on the health of the cows, especially on the oxidative stability of the cows, by increasing total thiols (P = 0.03), higher plasma ferric reducing capacity (FRAP) (P = 0.01), and total antioxidant capacity (TAC) (P = 0.01). In the oxidative stability of the milk produced by the treated animals, there was also an increase in TAC (P = 0.05) and FRAP (P = 0.03). Discreet changes were observed in the ruminal environment with a decreasing trend in pH (P = 0.04) but an increase in bacterial activity (P = 0.05) and protozoa counts (P = 0.07) in cows that consumed the additive. GSO consumption affected the fatty acid profile in milk, increasing saturated fatty acids (SFA) (P = 0.05) and reducing unsaturated fatty acids (UFA) (P = 0.03). The oil did not affect milk production or efficiency in the postpartum period. Based on this information, it is concluded that the addition of GSO positively affects the cow's antioxidant system.

Green sonochemical synthesis of ZnCo2O4 decorated with carbon nanofibers for enhanced electrochemical detection of bisphenol A in food products.

The facile sonochemical synthesis is reported of zinc cobalt oxide (ZnCo2O4) composited with carbon nanofiber (CNF). Structural, chemical, and morphological were characterized by X-ray diffraction (XRD), X-ray photoluminescent spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and transmittance electron microscopy (TEM), respectively. ZnCo2O4/CNF-modified GCE was applied to the detection of bisphenol A (BPA). The modified GCE shows enhanced sensing performance towards BPA, which includes a linear range (0.2 to 120 µM L-1) alongside a low limit of detection (38.2 nM L-1), low interference, and good stability. Detection of lower concentrations of BPA enables real sample analysis in the food industries (milk, orange juice, yogurt, tap water, and baby feeding bottles). Surprisingly, the BPA was detected in milk 510 nM L-1, orange juice 340 nM L-1, yogurt 1050 nM L-1, and tap water 140 nM L-1. Moreover, an interaction mechanism between the BPA analyte and ZnCo2O4 was discussed.

A Cost-Effective and Sensitive Method for the Determination of Lincomycin in Foods of Animal Origin Using High-Performance Liquid Chromatography.

BACKGROUND: Lincomycin (LIN) is extensively used for treating diseases in livestock and promoting growth in food animal farming, and it is frequently found in both the environment and in food products. Currently, most of the methods for detecting lincomycin either lack sensitivity and precision or require the use of costly equipment such as mass spectrometers. RESULT: In this study, we developed a reliable high-performance liquid chromatography-ultraviolet detection (HPLC-UVD) method and used it to detect LIN residue in 11 types of matrices (pig liver and muscle; chicken kidney and liver; cow fat, liver and milk; goat muscle, liver and milk; and eggs) for the first time. The tissue homogenates and liquid samples were extracted via liquid-liquid extraction, and subsequently purified and enriched via sorbent and solid phase extraction (SPE). After nitrogen drying, the products were derivatized with p-toluene sulfonyl isocyanic acid (PTSI) (100 µL) for 30 min at room temperature. Finally, the derivatized products were analyzed by HPLC at 227 nm. Under the optimized conditions, the method displayed impressive performance and demonstrated its reliability and practicability, with a limit of detection (LOD) and quantification (LOQ) of LIN in each matrix of 25-40 µg/kg and 40-60 µg/kg, respectively. The recovery ranged from 71.11% to 98.30%. CONCLUSIONS: The results showed that this method had great selectivity, high sensitivity, satisfactory recovery and cost-effectiveness-fulfilling the criteria in drug residue and actual detection requirements-and proved to have broad applicability in the field of detecting LIN in animal-derived foods.

Children's Iodine Intake from Dairy Products and Related Factors: A Cross-Sectional Study in Two Provinces of China.

Dairy products are a significant source of iodine, and their contribution to iodine intake must be evaluated regularly. However, there is a lack of data on iodine intake from dairy products in China. Through a cross-sectional study, we determined the iodine content of dairy products in the Chinese diet and estimated iodine intake among Chinese children. Intake records for 30 consecutive days were used to investigate the consumption of dairy products by 2009 children from Yunnan and Liaoning Provinces. The iodine contents of 266 dairy products with high intake frequency were determined using inductively coupled plasma-mass spectrometry (ICP-MS). We then calculated the iodine intake and contribution of dairy products and explored the related factors of dairy iodine intake through a generalized linear mixed model. Ultra-high-temperature (UHT) sterilized milk accounted for 78.7% of the total dairy products, with an iodine content of 23.0 µg/100 g. The dairy product intake rate of children in China was 83.6%, with an average daily intake of 143.1 g. The median iodine intake from milk and dairy was 26.8 µg/d, 41.5% of the estimated average recommendation (EAR) for younger children and 31.8% of the EAR for older children. The daily milk iodine intake of children in Yunnan Province was 9.448 µg/day lower than that of children in Liaoning Province (p < 0.001), and the daily iodine intake of children in rural areas was 17.958 µg/day lower than that of children in urban areas (p < 0.001). Chinese dairy products were rich in iodine, and the content of iodine was intermediate to that reported in Europe and the USA. However, children's daily intake of milk iodine was lower than that of children in other developed countries due to the lower daily intake of dairy products, especially those in rural areas.

Stability and expression of K-ras mimotopes in freeze-dried recombinant Lactococcus lactis NZ3900-fermented milk powder during storage in vacuum packaging.

AIMS: This study aims to evaluate the storage stability of the freeze-dried recombinant Lactococcus lactis NZ3900-fermented milk powder expressing K-ras (Kristen rat sarcoma viral oncogene homolog) mimotopes targeting colorectal cancer in vacuum packaging. METHODS AND RESULTS: The freeze-dried L. lactis-fermented milk powder stored in 4-ply retortable polypropylene (RCPP)-polyamide (PA)-aluminium (AL)-polyethylene terephthalate (PET) and aluminium polyethylene (ALPE) was evaluated throughout 49 days of accelerated storage (38°C and 90% relative humidity). The fermented milk powder stored in 4-ply packaging remained above 6 log10 CFU g-1 viability, displayed lower moisture content (6.1%), higher flowability (43° angle of repose), water solubility (62%), and survivability of L. lactis after simulated gastric and intestinal digestion (>82%) than ALPE packaging after 42 days of accelerated storage. K-ras mimotope expression was detected intracellularly and extracellularly in the freeze-dried L. lactis-fermented milk powder upon storage. CONCLUSIONS: This suggests that fermented milk powder is a suitable food carrier for this live oral vaccine.

Cryogel with Modular and Clickable Building Blocks: Toward the Ultimate Ideal Macroporous Medium for Bacterial Separation.

The lack of practical platforms for bacterial separation remains a hindrance to the detection of bacteria in complex samples. Herein, a composite cryogel was synthesized by using clickable building blocks and boronic acid for bacterial separation. Macroporous cryogels were synthesized by cryo-gelation polymerization using 2-hydroxyethyl methacrylate and allyl glycidyl ether. The interconnected macroporous architecture enabled high interfering substance tolerance. Nanohybrid nanoparticles were prepared via surface-initiated atom transfer radical polymerization and immobilized onto cryogel by click reaction. Alkyne-tagged boronic acid was conjugated to the composite for specific bacteria binding. The physical and chemical characteristics of the composite cryogel were analyzed systematically. Benefitting from the synergistic, multiple binding sites provided by the silica-assisted polymer, the composite cryogel exhibited excellent affinity toward S. aureus and Salmonella spp. with capacities of 91.6 × 107 CFU/g and 241.3 × 107 CFU/g in 0.01 M PBS (pH 8.0), respectively. Bacterial binding can be tuned by variations in pH and temperature and the addition of monosaccharides. The composite was employed to separate S. aureus and Salmonella spp. from spiked tap water, 40% cow milk, and sea cucumber enzymatic hydrolysate, which resulted in high bacteria separation and demonstrated remarkable potential in bacteria separation from food samples.

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.

Multi-functional nanozyme-based colorimetric, fluorescence dual-mode assay for Salmonella typhimurium detection in milk.

Rapid and high-sensitive Salmonella detection in milk is important for preventing foodborne disease eruption. To overcome the influence of the complex ingredients in milk on the sensitive detection of Salmonella, a dual-signal reporter red fluorescence nanosphere (RNs)-Pt was designed by combining RNs and Pt nanoparticles. After being equipped with antibodies, the immune RNs-Pt (IRNs-Pt) provide an ultra-strong fluorescence signal when excited by UV light. With the assistance of the H2O2/TMB system, a visible color change appeared that was attributed to the strong peroxidase-like catalytic activity derived from Pt nanoparticles. The IRNs-Pt in conjunction with immune magnetic beads can realize that Salmonella typhimurium (S. typhi) was captured, labeled, and separated effectively from untreated reduced-fat pure milk samples. Under the optimal experimental conditions, with the assay, as low as 50 CFU S. typhi can be converted to detectable fluorescence and absorbance signals within 2 h, suggesting the feasibility of practical application of the assay. Meanwhile, dual-signal modes of quantitative detection were realized. For fluorescence signal detection (emission at 615 nm), the linear correlation between signal intensity and the concentration of S. typhi was Y = 83C-3321 (R2 = 0.9941), ranging from 103 to 105 CFU/mL, while for colorimetric detection (absorbamce at 450 nm), the relationship between signal intensity and the concentration of S. typhi was Y = 2.9logC-10.2 (R2 = 0.9875), ranging from 5 × 103 to 105 CFU/mL. For suspect food contamination by foodborne pathogens, this dual-mode signal readout assay is promising for achieving the aim of convenient preliminary screening and accurate quantification simultaneously.

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 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.

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.

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.

Influence of additive and maternal effects on production and reproduction traits in Murrah buffaloes: Insights from Bayesian analysis.

The aim of this research was to assess genetic parameters for first lactation production and reproduction traits in Murrah buffaloes by employing additive and maternal effects. Data on pedigree and specific traits of 640 Murrah buffaloes were gathered from 1997 to 2020. These traits encompassed first lactation milk yield (FLMY), 305-day first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY), first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic evaluations employed six univariate animal models, accounting for both direct and maternal effects, facilitated by THRGIBBS1F90 and POSTGIBBSF90 programs. Fixed factors included in the analysis were period of calving, season of calving and age at first calving. The Bayesian estimates for direct heritability, derived from the most suitable model, were as follows: FLMY: 0.28 ± 0.01, 305FLMY: 0.30 ± 0.01, FLL: 0.19 ± 0.01, FPY: 0.18 ± 0.01, FSP: 0.12 ± 0.01, FCI: 0.14 ± 0.01 and FDP: 0.12 ± 0.01. Maternal effects were found significant, ranging from 5% to 10%, in first lactation traits under Model 2 and Model 5. Additionally, positive and significant genetic and phenotypic correlations were observed among the studied traits. In conclusion, selection based on 305-day first lactation milk yield suggests potential for genetic enhancement in Murrah buffaloes, advocating its inclusion in breeding programmes to bolster early performance. Also, consideration of maternal influences is necessary for genetic progress of animals.