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Food Research International (Ottawa,... Aug 2024The effect of 90, 180 and 270 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP) on the...
The effect of 90, 180 and 270 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP) on the solubilisation of proteins and minerals and the rheological and textural properties of processed cheese (PC) prepared from Gouda cheese ripened for 30-150 d at 8°C was studied. The solubilisation of individual caseins and Ca and the maximum loss tangent during temperature sweeps of PC made from Gouda cheese increased, while hardness of PC decreased with ripening duration of the Gouda cheese. Levels of soluble Ca in PC increased with increasing concentration of TSC and SHMP, but decreased with increasing concentration of DSP. The solubilisation of casein and Ca due to ripening of Gouda cheese used for manufacturing PC could explain the changes in texture and loss tangent of PC. The results suggest that DSP, TSC or SHMP in PC formulation can form insoluble Ca-phosphate, soluble Ca-citrate or insoluble casein-Ca-HMP complexes, respectively, that influence casein solubilisation differently and together with levels of residual intact casein determine the functional attributes of PC.
Topics: Cheese; Food Handling; Caseins; Solubility; Rheology; Citrates; Calcium; Phosphates; Hardness; Time Factors; Calcium Phosphates
PubMed: 38945567
DOI: 10.1016/j.foodres.2024.114587 -
Food Research International (Ottawa,... Aug 2024The structural and functional properties of whey-quercetin and whey hydrolysate-quercetin conjugates synthesized using alkaline and free radical-mediated methods (AM and...
The structural and functional properties of whey-quercetin and whey hydrolysate-quercetin conjugates synthesized using alkaline and free radical-mediated methods (AM and FRM) coupled with sonication were studied. FTIR showed new peaks at 3000-3500 cm (N-H stretching regions) and the 1000-1100 cm region with the conjugates. Conjugation increased the random coils and α-helix content while decreasing the β-sheets and turns. It also increased the particle size and surface hydrophobicity which was significantly (p < 0.05) higher in AM than FRM conjugates. AM conjugates had higher radical scavenging activity but lower quercetin content than FRM conjugates. Overall, the functional properties of whey-quercetin conjugates were better than whey hydrolysate-quercetin conjugates. However, hydrolysate conjugates had significantly higher denaturation temperatures irrespective of the method of production. Sonication improved the radical scavenging activity and quercetin content of FRM conjugates while it decreased both for AM conjugates. This study suggested that whey-quercetin conjugates generally had better quality than whey hydrolysate conjugates and sonication tended to further improve these properties. This study highlights the potential for using camel whey or whey hydrolysate-quercetin conjugates to enhance the functional properties of food products in the food industry.
Topics: Quercetin; Animals; Camelus; Sonication; Hydrophobic and Hydrophilic Interactions; Protein Hydrolysates; Whey; Antioxidants; Whey Proteins; Free Radical Scavengers; Spectroscopy, Fourier Transform Infrared; Free Radicals; Particle Size; Hydrogen-Ion Concentration
PubMed: 38945563
DOI: 10.1016/j.foodres.2024.114562 -
Journal of Dairy Science Jun 2024High-yielding dairy cows encounter metabolic challenges in early lactation. Typically, β-hydroxybutyrate (BHB), measured at a specific time point is employed to...
High-yielding dairy cows encounter metabolic challenges in early lactation. Typically, β-hydroxybutyrate (BHB), measured at a specific time point is employed to diagnose the metabolic status of cows based on a predetermined threshold. However, in early lactation, BHB is highly dynamic, and there is high interindividual variability in its time profile. This could limit the effectiveness of the single measurement and threshold-based diagnosis probably contributing to the disparities in reports linking metabolic status with productive and reproductive outcomes. This research delves into the examination of the trajectories of BHB to unveil inter-cow variations and identify latent metabolic groups. We compiled a data set from 2 observational studies involving a total of 195 lactations from multiparous Holstein Friesian cows. The data set encompasses measurements of BHB, NEFA, and insulin from blood samples collected at 3, 6, 9, and 21 d in milk (DIM), along with weekly determinations of milk composition and fatty acids (FA) proportions in milk fat. In both experiments, milk yield (MY) and feed intake were recorded daily during the first month of lactation. We explored interindividual and intraindividual variations in metabolic responses using the trajectories of blood BHB and evaluated the presence of distinct metabolic groups based on such variations. For this purpose, we employed the growth mixture model (GMM), a trajectory clustering technique. Our findings unveil novel insights into the diverse metabolic responses among cows, encompassing both trajectory patterns and the magnitude of blood BHB concentrations. Specifically, we identified 3 latent metabolic groups: the "QuiBHB" cluster (≈10%) exhibited a higher initial BHB concentration than other clusters, peaking on d 9 (average maximum BHB of 2.4 mM) and then declining by d 21; the "SloBHB" cluster (≈23%) started with a lower BHB concentration, gradually increasing until d 9, and at the highest BHB concentration at d 21 (1.6 mM serum BHB at the end of the experimental period); and the "LoBHB" cluster (≈67%) began with the lowest serum BHB concentration (serum BHB <0.75 mM), remaining relatively stable throughout the sampling period. Notably, the 3 metabolic groups exhibited significant physiological disparities, evident in blood NEFA and insulin concentrations. The QuiBHB and SloBHB cows exhibited higher NEFA and lower insulin concentrations as compared with the LoBHB cows. Interestingly, these metabolic differences extended to MY and DMI during the first month of lactation. The elevated BHB concentrations observed in QuiBHB cows were linked with lower DMI and MY as compared with SloBHB and LoBHB cows. Accordingly, these animals were considered metabolically impaired. Conversely, SloBHB cows displayed higher MY along with increased DMI, and thus the elevated BHB might be indicative of an adaptive response for these cows. The QuiBHB cows also displayed higher proportions of unsaturated FA (UFA), monounsaturated FA (MUFA), and total C18:1 FA in milk during the first week of lactation. Prediction of the QuiBHB cows using these FA and test day variables resulted in moderate predictive accuracy (ROC > 0.7). Given the limited sample size for the development of prediction models, and the variation in DIM among samples in the same week, the result is indicative of the predictive potential of the model and room for model optimization. In summary, distinct metabolic groups of cows could be identified based on the trajectories of blood BHB in early lactation.
PubMed: 38945267
DOI: 10.3168/jds.2024-24762 -
Journal of Dairy Science Jun 2024Milk serves as an important dietary source of bioactive peptides, offering notable benefits to individuals. Among the antioxidant short peptides (di- and tripeptides)...
Milk serves as an important dietary source of bioactive peptides, offering notable benefits to individuals. Among the antioxidant short peptides (di- and tripeptides) generated from gastrointestinal digestion are characterized by enhanced bioavailability and bioaccessibility, while assessing them individually presents a labor-intensive and expensive challenge. Based on 4 distinct types of amino acid descriptors (physicochemical, 3D structural, quantum, and topological attributes) and genetic algorithms for feature selection, 1 and 4 machine learning predicted models separately for di- and tripeptides with ABTS radical scavenging capacity exhibited excellent fitting and prediction ability with random forest regression as machine learning algorithm. Intriguingly, the electronic properties of N-terminal amino acid were considered as only factor affecting the antioxidant capacity of dipeptides containing both tyrosine and tryptophan. Four peptides from the potential di- and tripeptides exhibited highly predicted values by the constructed predicted models. Subsequently, a total of 45 dipeptides and 52 tripeptides were screened by a customized workflow in goat milk during in vitro simulated digestion. In addition to 5 known antioxidant dipeptides, 9 peptides were quantified during digestion, falling within the range of 0.04 to 1.78 mg L. Particularly noteworthy was the promising in vivo functionality of antioxidant dipeptides with N-terminal tyrosine, supported by in silico assays. Overall, this investigation explored crucial molecular properties influencing antioxidant short peptides and high-throughput screening potential peptides with antioxidant activity from goat milk aided by machine learning, thereby facilitating the identification of novel bioactive peptides from milk-derived proteins and paving the way for understanding their metabolites during digestion.
PubMed: 38945266
DOI: 10.3168/jds.2024-24887 -
Journal of Dairy Science Jun 2024Factors contributing to variations in the quality and microbiota of ensiled forages and in bulk tank microbiota in milk from cows fed different forages were...
Factors contributing to variations in the quality and microbiota of ensiled forages and in bulk tank microbiota in milk from cows fed different forages were investigated. Nutritional quality, fermentation parameters and hygiene quality of forage samples and corresponding bulk tank milk samples collected in 3 periods from 18 commercial farms located in northern Sweden were compared. Principal coordinates analysis revealed that the microbiota in forage and bulk milk, analyzed using 16S rRNA gene-based amplicon sequencing, were significantly different. The genera Lactobacillus, Weissella and Leuconostoc dominated in forage samples, whereas Pseudomonas, Staphylococcus and Streptococcus dominated in bulk milk samples. Forage quality and forage-associated microbiota were affected by ensiling method and by use of silage additive. Forages stored in bunker and tower silos (confounded with use of additive) were associated with higher levels of acetic and lactic acid and Lactobacillus. Forage ensiled as bales (confounded with no use of additive) was associated with higher dry matter content, water-soluble carbohydrate content, pH, yeast count and the genera Weissella, Leuconostoc and Enterococcus. For bulk tank milk samples, milking system was identified as the major factor affecting the microbiota and type of forage preservation had little impact. Analysis of common amplicon sequence variants (ASVs) suggested that forage was not the major source of Lactobacillus found in bulk tank milk.
PubMed: 38945265
DOI: 10.3168/jds.2024-24971 -
Journal of Dairy Science Jun 2024Yogurt is popular as a natural and healthy food, but its flavor greatly affects acceptability by consumers. Flavor compounds of yogurt is generally produced by the... (Review)
Review
Yogurt is popular as a natural and healthy food, but its flavor greatly affects acceptability by consumers. Flavor compounds of yogurt is generally produced by the metabolism of lactose, protein and fat, and the resulting flavors include carbonyls, acids, esters and alcohols, etc. Each flavor compounds could individually provide the corresponding flavor, or it can be combined with other compounds to form a new flavor. The flavor network was formed among the metabolites of milk components, and acetaldehyde, as the central compounds, played a role in connecting the whole network. The flavor compounds can be affected by many factors, such as the use of different raw milks, ways of homogenization, sterilization, fermentation, post ripening, storage condition and packaging materials, etc., which can affect the overall flavor of yogurt. This paper provides an overview of the volatile flavor compounds in yogurt, the pathways of production of the main flavor compounds during yogurt fermentation, and the factors that influence the flavor of yogurt including type of raw milk, processing, and storage. It also tries to provide theoretical guidance for the product of yogurt in ideal flavor, but further research is needed to provide a more comprehensive description of the flavor system of yogurt.
PubMed: 38945263
DOI: 10.3168/jds.2024-24875 -
Journal of Dairy Science Jun 2024The uptake of AA in mammary tissues is affected by prolactin (PRL). To investigate whether PRL-induced AA uptake is involved in L-type AA transporter 1 (LAT1), we...
The uptake of AA in mammary tissues is affected by prolactin (PRL). To investigate whether PRL-induced AA uptake is involved in L-type AA transporter 1 (LAT1), we analyzed the changes of AA in the medium of dairy cow mammary epithelial cells in the presence of PRL or PRL plus BCH, an inhibitor of LAT1. Then Western blot and luciferase assay were used to detect the regulation mechanism of PRL on LAT1 expression and function. Our results showed that Thr, Val, Met, Ile, Leu, Tyr, Lys, Phe, and His are LAT1 substrates and could be transported into mammary epithelial cells via LAT1. PRL stimulation increased the uptake of most AA into mammary epithelial cells of dairy cows, however, inhibition of LAT1 transport activity reduced PRL-induced AA uptake, suggesting that the effect of PRL on AA transport depends on LAT1 expression and function. PRL stimulation upregulated LAT1 expression and plasma membrane location not only in dairy cow mammary epithelial cells, but also in mouse mammary epithelial cell line HC11. Western blot showed that PI3K-AKT-mTOR signaling could be activated in PRL-stimulated mammary epithelial cells. Treatment of cells with LY294002 decreased PI3K-AKT-mTOR activation, as well LAT1 expression, that in turn decreased milk protein synthesis. Luciferase assay showed PRL treatment increased the promoter activity of LAT1 promoter fragment -419∼-86 bp. Treatment of cells with LY294002, an inhibitor of PI3K, or SC79, an activator of AKT abolished or promoted the transcriptional activity of this promoter fragment in the presence of PRL. These results suggested that the -419∼-86 bp fragment of LAT1 promoter mediates the action of PI3K-AKT-mTOR signaling on LAT1 transcription in mammary epithelial cells of dairy cows, which in turn increased LAT1 expression and AA uptake.
PubMed: 38945262
DOI: 10.3168/jds.2024-24746 -
Journal of Dairy Science Jun 2024Despite considerable research efforts, lipase catalysis in a fluid milk system with aqueous multi-component mixtures containing multiple microphases, remains...
Despite considerable research efforts, lipase catalysis in a fluid milk system with aqueous multi-component mixtures containing multiple microphases, remains challenging. Pickering interfacial biocatalysis (PIB) platforms are typically fabricated with organic solvents/lipids and water. Whether a PIB with excellent catalytic performance can be constructed in complex milk mixtures remains unknown. Here, we challenged PIB with skim milk, and a small amount of flaxseed oil, and phytosterols as a model system for transesterification and lipolysis to enhance quality and flavor. The amino-modified mesoporous silica spheres (MSS-N) were employed as an emulsifier and carrier of lipase AYS (AYS@MSS-N). The conversion of phytosterol esters reached 75.5% at 1.5 h and prepared phytosterol ester-fortified milk with a content of 1.0 g/100 mL. The relative conversion rate remained above 70% after 6 cycles. In addition, the fortified milk showed an intensified and favorable effect on sensory traits through volatile flavor composition analysis. The findings provide a versatile alternative for PIB applications in complex environments, i.e., milk, which might inspire a new bioprocess strategy for dairy products.
PubMed: 38945261
DOI: 10.3168/jds.2024-25037 -
Journal of Dairy Science Jun 2024The primary objective of this study was to evaluate the association between preweaning diarrhea and measures of survival, health and production. The measures of interest...
The primary objective of this study was to evaluate the association between preweaning diarrhea and measures of survival, health and production. The measures of interest included survival (mortality before first calving and time to removal from the herd), health (retained fetal membranes, metritis, mastitis and somatic cell count), and production (305d mature equivalent milk yield and time to first calving). A secondary objective was to investigate if these associations varied according to the age of the calf when the case of diarrhea occurred. Herd records from a farm located in Southern Australia were used to conduct a retrospective cohort study where subjects (calves) with diarrhea were enrolled at the time of their first case along with 2 subjects without diarrhea, matched for age (±3 d) and date of birth (±15 d), amounting to 9833 calves in the data set. Survival analysis was conducted to determine if preweaning diarrhea was associated with death in the short term (first 20 d after enrollment), medium term (21 to 100 d after enrollment) and long-term (101 d after enrollment to first calving). Crude incidence rate ratios, Kaplan-Meier curves and hazard ratios (HR, Cox regression) were derived for each event-based outcome (e.g., death, calving, mastitis). Multivariable linear models were used for continuous outcomes. Calves with preweaning diarrhea had greater mortality rates in the short term (hazard ratio, HR = 2.48, 95% CI: 1.87-3.29) and medium term (HR = 1.89, 95% CI: 1.41-2.55) but not in the long term (HR = 0.98, 95% CI: 0.79-1.22). A small negative association between preweaning diarrhea and time to first calving was found, with calves with diarrhea calving 4 d later than calves without diarrhea (HR = 0.95, 95% CI: 0.91-1.00). Rates of post-calving removal from the herd (death or culling) were higher in calves with a history of preweaning diarrhea (HR = 1.13, 95% CI: 1.01 to 1.26), as were peak lactation log somatic cell count (+0.08, 95% CI: 0.02 to 0.14). Further research is needed to replicate these novel findings as they are based on exploratory analyses and could be spurious findings. No substantial associations were observed for the other measures of interest. Our study findings support existing research demonstrating the significance of preweaning diarrhea as a significant cause of calf mortality, and raises new hypotheses about other potential impacts during lactation.
PubMed: 38945259
DOI: 10.3168/jds.2023-24544 -
Environmental Pollution (Barking, Essex... Jun 2024The rapidly growing demand for food in human societies has led to the extensive use of fertilizers, significantly contributing to water pollution. Grey water footprints...
The rapidly growing demand for food in human societies has led to the extensive use of fertilizers, significantly contributing to water pollution. Grey water footprints (GWF) serve as a crucial method for measuring Non-point Source (NPS) pollution, particularly in agriculture. Traditional assessments of agricultural GWF neglect biologically fixed nitrogen and the use of organic fertilizers. This research proposed a modified method to assess the GWF of Chinese agriculture from 2000 to 2020, considering the impact of Nitrogen fixation in crops and the use of organic fertilizer. We also analyzed the determinants of Agricultural Nitrogen Fixation Intensity (ANFI) using the Logarithmic Mean Divisia Index (LMDI) method to better understand factors influencing agricultural GWF. Our findings include: (1) Grain cereals (e.g., maize, rice and wheat) significantly contribute to nitrogen fixation in crop organs, accounting for 87.7%, whereas the other six economic crops contribute the rest of 12.3%. Human wastes accounts Nitrogen emissions for 1.40%, and emissions by livestock product, red meat contributes 16.26%, while white meat, eggs, and milk collectively contribute 82.34%. (2) Across China, there is an overestimation of GWF by 22.4 hundred million per year, about 5.13% of the total GWF measured by traditional methods. It appears that the overestimation of GWF in plain regions with more arable land tends to be somewhat more pronounced compared to plateau and coastal municipalities. Biotechnological advancements in capacity of nitrogen fixation for key crops (e.g., maize, wheat, rice) can alleviate agricultural water pollution. The modified methodology provides a robust scientific basis for more precise application of GWF assessments, highlighting the substantial overestimation by traditional methods in China.
PubMed: 38945196
DOI: 10.1016/j.envpol.2024.124457