內(nèi)容: Hexanal contributes significantly to meat flavor. The aim of this study was to identify the metabolic pathways of hexanal formation in chicken meat. We found 32 metabolites associated with hexanal content in chicken meat, mainly including fatty acids (linoleic acid, etc., positive correlation) and some amino acids (L-proline, etc., negative correlation). A comparative analysis of the expression of these 32 metabolites between two groups of chickens with high- and low-hexanal content revealed that L-proline and phenylacetaldehyde were downregulated, while ADP-ribose and 4-methylphenol were upregulated in the high-hexanal content chickens. It was also found that the increase of ADP-ribose induced the conversion of L-proline to other amino acids, such as arginine, through a process likely involving the pyrimidine metabolism pathway, leading to a reduction in proline content, which in turn abolished the inhibitory effect of proline on hexanal and enhanced the formation of hexanal. These findings confirm the effect of linoleic acid on hexanal content, and also reveal a negative regulatory effect of proline on the production of hexanal and its elimination mechanism in chicken meat.

內(nèi)容: Edible mushroom proteins are the promising ones with the advantages of complete essential amino acid profile and multiple functional activities. To reinforce their applications in functional food development, this study comprehensively evaluated the physicochemical and functional properties of protein isolates from 5 mushroom species, i.e., Pleurotus eryngii (PEP), Pleurotus ostreatus (POP), Lentinula edodes (LEP), Flammulina velutipes (FVP) and Hypsizygus marmoreus (HMP). Results showed that PEP, LEP, FVP, POP and HMP exhibited better protein solubility (PS), water holding capacity (WHC), emulsification activity index (EAI), and foaming capacity (FC) than those of soybean protein and pea protein isolates (PPI). PEP (51.95%) and POP (49.15%) had a higher amount of β-sheet structure. Principal component analysis and correlation analysis showed that the seven proteins could be divided into 3 clusters, and WHC, EAI and FC were significantly positively correlated with PS and β-sheet. The least gelation concentration of PEP (16%) and FVP (16%) at pH 6.0 and 7.0 was similar to PPI, and PEP showed better hardness, springiness and rheological properties than other proteins gels. Overall, our study showed that 5 edible mushroom proteins possessed excellent functionalities (except for gelling capacity), which provided novel insights on unexploited sources of mushroom proteins used as protein-based foods in the food industry.

內(nèi)容: Structured-illumination reflectance imaging (SIRI) provides a new means for food quality detection. This original work investigated the capability of (SIRI) technique coupled with multivariate chemometrics to evaluate the microbial contamination in pork inoculated with Pseudomonas fluorescens and Brochothrix thermosphacta during storage at different temperatures. The prediction performances based on different spectrum and the textural features of direct component and amplitude component images demodulated from the SIRI pattern, as well as their data fusion were comprehensively compared. Based on the full wavelength spectrum (420–700 nm) of amplitude component images, the orthogonal signal correction coupled with support vector machine regression provided the best predictions of the number of P. fluorescens and B. thermosphacta in pork, with the determination coefficients of prediction (Rp2) values of 0.870 and 0.906, respectively. Besides, the prediction models based on the amplitude component or direct component image textural features and the data fusion models using spectrum and textural features from direct component and amplitude component images cannot significantly improve their prediction accuracy. Consequently, SIRI can be further considered as a potential technique for the rapid evaluation of microbial contaminations in pork meat.

內(nèi)容: Cor a 14 is one of the most vital allergens in hazelnuts. However, the features of intestinal metabolites and microbiota associated with Cor a 14-induced allergy remain unclear. In this study, we established a hazelnut Cor a 14-allergic BALB/c mice model, which was distinguished by the dropped temperature and enhanced allergic inflammatory factor levels in serum. Faeces were collected to detect characteristics of the intestinal metabolites by untargeted metabolomics and the gut microbiota by 16S rRNA sequencing. The α- and β-diversity of gut microbiota in Cor a 14-allergic mice differed from the controls with elevated relative abundance of Lactobacillus and reduced relative abundances of Odoribacter, Chloroplast, Alistipes and Lachnospiraceae_NK4A136_group. Untargeted metabolomics results revealed that 238 significantly differential metabolites (111 up-regulated, 127 down-regulated) were identified, of which, L-tryptophan, histamine and N-acetylhistamine were remarkably accumulated and primarily enriched in the enhanced L-tryptophan and histidine metabolism pathways. Spearman correlation analysis suggested that L-tryptophan was positively correlated with allergic indicators and screened as the potential biomarker for Cor a 14 allergy. Collectively, our findings uncovered the characteristics of intestinal metabolites and gut microbiota during Cor a 14 anaphylaxis and provided new potential insights for diagnosis of hazelnut allergy.

內(nèi)容: Pu-erh tea has been shown to reduce gut inflammation in dextran sulfate sodium (DSS)-induced mice. Also, we found abnormal liver cholesterol metabolism in DSS-induced mice. However, it’s not clear how Pu-erh tea improves DSS-induced impaired liver cholesterol metabolism. Here, we established the DSS-induced model and clarified that DSS exacerbated gut inflammation accompanied by disorders of liver cholesterol metabolism. Pu-erh tea reshaped gut microbes, limited gut oxidative stress and inflammation (nicotinamide adenine dinucleotide phosphate oxidase 2/reactive oxygen species/myeloid differentiation primary response protein 88/nuclear factor kappa-B, 24.97%?52.89%), reduced gut bile acid reabsorption (up-regulation of farnesoid X receptor (FXR)/fibroblast growth factor 15, 24.53%?55.91%), and promoted liver bile acid synthesis (up-regulation of peroxisome proliferator-activated receptor-α/cholesterol 7-alpha hydroxylase, 34.65%?79.14%), thereby partly restoring liver cholesterol metabolism (regulated FXR/small heterodimer partner/sterol-regulatory element binding proteins, 53.19%?95.40%). Altered bile acid metabolic profiles (increased chenodeoxycholic acid, ursodeoxycholic acid, lithocholic acid, etc.) may also improve liver cholesterol metabolism by altering gut and liver inflammation. Thus, gut microbial reshaping and altered bile acid metabolism may be key targets of Pu-erh tea for improving DSS-induced liver cholesterol metabolism disorders via the gut-gut microbe-bile acid-liver axis.

內(nèi)容: Sea cucumber derived sulfated sterols significantly ameliorated insulin resistance and decreased lipid accumulation compared to plant sterols. Interestingly, our recent study found that intervention with sea cucumber sulfated sterols could significantly increase blood glucose levels of healthy mice in the presence of glucose, while cholesterol sulfate, as one of sulfated sterols, did not have the same effect. However, the exact mechanism of sulfated sterols on glucose metabolism is still unknown. In the present study, we investigated the potential mechanism by which sulfated sterols influenced blood glucose homeostasis in healthy mice. Results showed that intervention with sea cucumber sulfated sterols did not affect the levels of hormones related to glucose metabolism, while led to a significant decrease in the synthesis of liver glycogen and muscle glycogen. Besides, the expression of proteins associated with the promotion of gluconeogenesis dramatically increased in the mice intervened with sea cucumber sulfated sterols. These findings suggested that sea cucumber sulfated sterols might change blood glucose metabolism in healthy mice by reducing glycogenesis and promoting gluconeogenesis.

內(nèi)容: Iron deficiency anemia (IDA) is a nutritional deficiency disease with a high incidence rate worldwide. Bioactive peptides are safe and effective, have multiple functions and can serve as potential candidates for alleviating IDA. In this study, the anti-anemia effects of tuna dark muscle peptides were explored in a diet-induced IDA mouse model. The results showed that tuna dark muscle peptides alleviated the IDA phenotype, oxidative stress and iron metabolism. In addition, tuna dark muscle peptides reversed gut microbiota dysbiosis in IDA mice. Furthermore, the transplanted fecal microbiota from tuna dark muscle peptide-treated mice also alleviated IDA symptoms and regulated iron metabolism and the gut microbiota, indicating that the anti-anemic effects were at least partially mediated by the gut microbiota. Thus, we identified a new and safe prebiotic material to alleviate IDA and provided ideas for the development of peptides. At the same time, these data also provided a theoretical basis for fecal microbiota transplantation to alleviate IDA.

內(nèi)容: The utilization of Lactobacillus plantarum (LP) in chili sauce production is well-known for its capacity to enhance product quality and sensory attributes. However, there is still limited knowledge regarding the taste-active metabolites in the sauce. To bridge this gap, our study employed metabolomics and web-based computational tools to investigate the dynamic changes of taste-active metabolites during chili sauce fermentation. By leveraging the advantages of the feature-based molecular network (FBMN), we conducted a rapid annotation of metabolites, successfully identifying 205 metabolites, a considerable portion of which were previously unreported. Through the utilization of the VirtualTaste tool, we identified dihydrosphingosine, lactic acid, isoleucine, phytosphingosine, and gluconic acid as potential taste indicators for quality control. Pathway enrichment analysis further supported their primary involvement in key biochemical pathways, including amino acid tRNA biosynthesis, phenylalanine, tyrosine, tryptophan biosynthesis, and sphingolipid metabolism. This investigation provides valuable insights into the underlying mechanisms contributing to the distinctive flavor profile of chili sauce.

內(nèi)容: In this work, a novel bifunctional zirconium dioxide@zeolitic imidazolate framework-90 (ZrO2@ZIF-90) nanozyme was successfully developed for the catalytic degradation and electrochemical detection of methyl parathion (MP). The ZrO2@ZIF-90 nanozyme with phosphatase hydrolysis activity can convert MP into p-nitrophenol (p-NP). The addition of ZrO2 riched in Lewis acid Zr(IV) sites significantly enhanced the phosphatase hydrolysis activity of ZIF-90. ZrO2@ZIF-90 also displayed satisfactory electrocatalytic performance on account of the high surface area, high porosity and powerful enrichment ability of the ZIF-90 and the excellent ion transfer capacity of ZrO2. A ZrO2@ZIF-90 nanozyme modified glassy carbon electrode (ZrO2@ZIF-90/GCE) was then fabricated to analyze p-NP formed through MP degradation. Under the optimized conditions, the developed sensor displayed satisfactory analytical performance with a low limit of detection of 0.53 μmol/L and two wide linear ranges (3-10 and 10-200 μmol/L). ZrO2@ZIF-90 nanozyme accomplished to the degradation and electrochemical detection of MP in river water and spiked fruits. This study identifies a promising new strategy for the design of bifunctional nanozymes for the detection of environmental hazards.

內(nèi)容: The anti-inflammatory properties of silkworm pupa peptide (SPP) have been recognized for their potential benefits in colitis treatment. However, the underlying mechanism of SPP in colitis animal models remains unclear. The objective of our work was to investigate the improving effect and the mechanism of action of SPP on a mouse model of dextran sulfate sodium (DSS)-induced colitis. The findings suggested that SPP effectively eased ulcerative colitis (UC) symptoms in mice by decreasing disease activity index, ameliorating histopathological injury, and decreasing serum and colonic markers of inflammation. In addition, our research findings demonstrated that SPP restored intestinal barrier function by increasing the production of tight junction proteins such as zonula occludens-1 (ZO-1), claudin-1, claudin-3, occludin, and adherens junction protein E-cadherin1. Further, SPP supplementation enhanced the concentration of short-chain fatty acids and positively altered the makeup of the gut bacteria in the mice’s gut. These findings underscore SPP’s ability to slow the progression of colitis and point to its possible use as a functional component in dietary supplements for the prevention of early-stage colitis.