内容: Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages. In this study, we used a mixed starter culture to ferment sausages and investigated the flavor turnover. During the fermentation of salami, the data from free amino acids (FAAs), free fatty acids (FFAs) and volatile flavor substances were used to assess the quality of salami. At the end of fermentation, the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group. Additionally, following inoculation with the mixed starter culture, the levels of glutamic acid, lysine, methionine, valine and leucine were significantly higher (P < 0.05) than those in the control group. Oleic acid (C18:1) and chondritic acid (C16:0) were the two most abundant FFAs in both salami samples with 45.86% and 26.07% on the 23th day in mixed culture inoculated salami. The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group (P < 0.05). In the volatile flavor substance analysis, a total of 61 volatile compounds were found. Ester compounds were progressively enriched with drying time, significantly increasing the flavor substances, like ethyl diphosgene, 1-octen-3-ol, and 2,3-butanediol at P < 0.05. The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds, which are the key core microorganisms affecting the flavor quality of fermented sausages.

内容: Neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, are associated with cognitive impairment and impaired brain glucose metabolism, posing significant challenges for the public health. We previously demonstrated that cyanidin 3-O-β-galactoside (Cy3Gal) from black chokeberry alleviated cognitive impairment in aging mice through regulating brain energy metabolism in a direct way. However, the indirect mechanisms in mitigating brain glucose hypometabolism remain underexplored. Here, we utilized a bilaterally intracerebroventricular injection of streptozotocin (ICV/STZ, 3 mg/kg bw)-induced brain glucose hypometabolism model to investigate the effects of Cy3Gal on cognitive impairment alleviation. Our findings revealed that Cy3Gal administration significantly improved memory deficit and cognitive impairment in ICV/STZ-administrated mice. Subsequently, Cy3Gal showed excellent abilities in inhibiting astrocyte overactivation, regulating neurotransmitters metabolism, and promoting synaptic plasticity. Furthermore, Cy3Gal enhanced brain glucose metabolism by improving glycolysis and the TCA cycle. Additionally, Cy3Gal modulated levels of gut microbiota-derived metabolites, including acetate, butyrate, histidine, glutamine, serine, valine and isoleucine, which were closely linked to brain glucose metabolism. The in vitro results further demonstrated that these metabolites played an important role in the neuron-astrocyte energy metabolism, which accounted for the alleviation of glucose hypometabolism. Overall, our findings suggest that Cy3Gal mitigates ICV/STZ-induced cognitive impairment by modulating gut microbiota-derived short-chain fatty acids and amino acids, which in turn improves brain glucose metabolism.

内容: Glehniae Radix has a wide range of pharmaceutical applications, and research on its main components has mainly focused on coumarins, alkaloids, lignans, and flavonoids, while neglecting the research on polysaccharides. Literature reports and our previous studies have shown that polysaccharides have certain therapeutic significance in immune regulation, antioxidant, anti-inflammatory and other aspects. Herein, the rat model of ulcerative colitis (UC) was established to evaluate the anti-inflammatory efficacy of the prepared Glehniae Radix polysaccharide (GLP) from the perspectives of inflammatory factors, intestinal tissue morphology, and microflora changes. The polysaccharides are mainly composed of galacturonic acid, rhamnose, glucose, galactose, and arabinose in molar ratios of 1.4:9.2:33.3:2.5:2.9, and GLP could downregulate the expression pro-inflammatory factors (interleukin 6, tumor necrosis factor α, and interferon γ) and significantly upregulate the expression of anti-inflammatory factor (interleukin 10). In addition, Glehniae Radix aqueous extract (GLA), GLP with low dosage and GLP with high dosage (GLPH) could increase the number of goblet cells, enhance the integrity of crypt structure, and reverse the status of inflammatory infiltrating cells. Moreover, GLA and GLPH could upregulate Lactobacillus and Lachnoclostridium in UC rats, and appropriately downregulate Lachnospiraceae_NK4A136_group, thereby optimizing the proportion of bacterial flora and improving the intestinal microbial environment. Our findings not only be valuable as theoretical materials for the further clinical applications of GLP, but the identified biomarkers and metabolic pathways also provide new clues for the diagnosis of UC.

内容: The pathophysiology of nonalcoholic fatty liver disease (NAFLD) was characterized by alterations in the intestinal microbiota and bile acids (BAs). Flaxseed powder (FLA) was rich in active components such as α-linolenic acid, dietary fiber, and lignans, which had lipid-lowering and anti-inflammatory effects. Here, we investigated whether FLA reduced liver fat and improved inflammation by modulating the gut microbiota, enriching bacteria involved in the production of 6α-hydroxylated BAs, and activating the gut-liver-BA metabolic pathway-specific receptor Takeda G protein-coupled receptor 5 (TGR5). Wild-type (WT) and TGR5 knockout mice were set up in a low-fat control group, a high-fat model group and a flaxseed powder intervention group for 12 weeks. At the end of the experiment, we examined the levels of lipids (TC, LDL-C, HDL-C, and TG), the levels of inflammatory factors (TNF-α and IL-6), the pathological changes in the liver, and the differences in the expression of key proteins (CYP7A1, TLR4, and NF-κB) in the liver of TGR5–/– and WT mice. In the current study, we found that 12 weeks of FLA intervention significantly attenuated the progression of NAFLD in WT mice, whereas TGR5 knockout exacerbated the extent of disease in mice with NAFLD. TGR5 gene knockout blocked the anti-inflammatory effect of FLA, but did not block its lipid-lowering effect. The TGR5 gene may be a key protein in the anti-inflammatory pathway of FLA, rather than a key protein in the lipid-lowering pathway of FLA. FLA intervention altered the relative abundance of gut microbiota with BA metabolizing enzymes, which in turn regulated the composition of intestinal BA, particularly the proportion of the key functional BAs 6α-hydroxylated BAs, thereby activating the intestinal BA-specific receptor TGR5, which might play a role in ameliorating inflammation. FLA might be a promising functional food for the prevention of NAFLD by modulating the microbiota and BAs.

内容: Herein, a reusable and portable surface-enhanced Raman spectroscopy (SERS) sandpaper was successfully synthesized for the sensitive detection of S-fenvalerate in foods. Commercial sandpapers were decorated with Ag@SiO2@Au nanoarrays via a liquid-liquid interface self-assembly method. The capacity of sandpaper to float directly on the cyclohexane-water interface allows nanoarrays to be formed directly on it, thereby minimizing stacking issues typically associated with nanoarray assemblies and significantly enhancing the sensitivity of S-fenvalerate detection. Moreover, the SERS sandpaper was reusable and portable due to its strong adhesion of the nanoarrays. Under optimized testing conditions, the developed SERS sandpaper method was capable of detecting S-fenvalerate, demonstrating a strong linear response within a concentration range of 10–7–103 μmol/L, with a limit of detection of 1.92 × 10−8 μmol/L. The analysis of spiked food samples containing S-fenvalerate using the developed SERS sandpaper afforded excellent recoveries (92.2%−109.7%). Additionally, the SERS sandpaper was successfully applied to quantify S-fenvalerate in real food samples, with results consistent with analyses conducted using gas chromatography.

内容: Skeletal muscle injuries are prone to induce fatigue, decrease resistance and imbalances in the body. Although ovalbumin (OVA) has such biological effect as promoting tissue development and immunomodulation, its impact on repairing skeletal muscle injuries has been rarely reported. In this study, a mouse model of muscle injury was constructed and found that OVA significantly increased muscle weight, muscle thickness, and exercise capacity in muscle-injured mice. Meanwhile, OVA improved the morphology of muscle tissues by reducing serum levels of urea nitrogen, creatine kinase, and lactate dehydrogenase, as well as decreasing the levels of inflammatory factors interleukin (IL)-1β, tumor necrosis factor α, and IL-6, respectively. In addition, transcriptomic and metabolomic analyses revealed that OVA could enhance muscle tissue morphology by upregulating the phosphatidylinositol 3-kinase-protein kinase B signaling pathway and improving amino acid metabolism through the upregulation of Col11a2, Ccn2, Thbs1, Tnc, Klf2, Bcl2l1, Adh3a1, and Rsad1. The study provided a theoretical foundation for understanding the molecular mechanisms in OVA-aided muscle injury repair.

内容: Inoculation of starter culture is a viable method to improve the quality of fermented foods, but its effect on the flavor metabolite profiles and the underlying mechanisms are still unclear. This study aimed to elucidate the effects of starters (Lactiplantibacillus plantarum (LP) and Staphylococcus simulans (SS) individually or in combination (LS)) on the flavor metabolite profiles of fermented sausages via metabolomics and genomics. L. plantarum markedly modified the composition of bacterial communities and made Lactobacillus spp. dominant in sausages (98.29% and 85.03% in LP and LS groups, respectively). Additionally, inoculation with a single starter, L. plantarum, and a mixed starter yielded similar non-volatile flavor metabolites, which were mainly characterized at the amino acid and peptide levels (relative intensities of 349.65 and 348.62 for the LP and LS groups, respectively). Meanwhile, the mixed starter group had the most volatile flavor metabolites (relative intensity of 34728.67), some of which were contributed by L. plantarum, such as ethyl acetate (relative intensities of 583.33 and 588.33 for the LP and LS groups, respectively) and benzaldehyde (relative intensities of 786.67 and 909.00 for the LP and LS groups, respectively), and several of which were generated by S. simulans, such as ethyl propionate (relative intensities of 214.67 and 136.67 for the SS and LS groups, respectively) and benzyl alcohol (relative intensities of 720.00 and 656.00 for the SS and LS groups, respectively). Furthermore, L. plantarum was found to possess more genes encoding peptidases (48) and carbohydrate-active enzymes (124), while S. simulans had more genes related to lipid hydrolysis (12). In conclusion, differences in the properties and combinations of indigenous strains play a crucial role in the generation of flavor metabolites in sausages.

内容: The high protein and phospholipid content of yolk granules, which are naturally occurring lipoprotein complexes, coupled with a low cholesterol level. The development and utilization of yolk granules require a detailed investigation of their nutritional composition and characteristics. This study aimed to analyze the differences in nutrient composition among yolk granules from different poultry (chicken, duck, and quail) by evaluating nutrient content, microstructure, and physicochemical properties, accompanying lipidomics techniques. The fi ndings revealed that the water, total lipid, and ash contents of duck yolk granules (DYG) were signifi cantly lower than those of chicken yolk granules (CYG) and quail yolk granules (QYG), while the average particle size of DYG was significantly higher than that of CYG and QYG. A total of 1146 lipids molecules were identifi ed through lipidome analysis, with glycerophospholipids (520) being the most abundant lipid class. The contents of sphingolipids content were highest in CYG, while the contents of glycerophospholipids, glycerides and fatty acyls were higher in QYG. QYG possesses a greater ω-3 and ω-6 polyunsaturated fatty acids content. Furthermore, 34, 19, and 51 lipid biomarker candidates were identifi ed in CYG/DYG, CYG/QYG, and DYG/QYG, respectively. This study off ers valuable insights into the nutritional properties of yolk granules from diff erent poultry eggs.

内容: Vine tea is documented in ancient Chinese books as having the function of promoting blood circulation. However, its effects and mechanisms remain unclear. The aim of this study was to comprehensively investigate the protective potential and mechanisms of vine tea in high-fat diet rat through a combination of in vivo and in vitro experiments. The efficacy of vine tea was evaluated using a high-fat diet rat model and an oxidized low-density lipoprotein-treated cell model, with physiological and biochemical indicators measured in rat serum and cell supernatants. Transcriptomics was utilized to investigate alterations mRNA expression following the administration of dihydromyricetin in cell model. Metabolomics and 16S rRNA sequencing was employed to examine changes in metabolites in the serum and changes in gut microbiota of high-fat diet rats after administering vine tea extract. Vine tea extract and dihydromyricetin can reduce elevated levels of lipids, including total cholesterol and triglycerides, following modeling. Transcriptomic data indicate that dihydromyricetin exerts its effects by regulating ferroptosis signaling pathways. Metabolomic analysis demonstrates that the administration of vine tea extract influences the vitamin K cycle and glutathione, thereby alleviating the progression of ferroptosis. Additionally, 16S rRNA sequencing reveals that vine tea extract increases Lactobacillaceae in the gut microbiota, which subsequently affects the levels of lysophosphatidylcholine, a major phospholipid component of oxidized low-density lipoprotein in serum. Our results indicate that vine tea can regulate ferroptosis signaling pathways and increase Lactobacillaceae in the gut microbiota, thereby exhibiting cardiovascular protective effects in high-fat diet rats.

内容: Okara is produced in large quantities annually in China, but much of it is discarded due to its high content of indigestible dietary fiber (DF), contributing to significant environmental challenges. Recognizing the underexplored medicinal potential of DF, we developed an efficient fermentation method to enhance the bioavailability of okara fiber. In this study, Pediococcus acidilactici IFJ-1, which has strong enzymatic production capabilities and beneficial effects on gastrointestinal flora modulation, was selected to ferment okara. Results showed decreases in viscosity and particle size, optimized surface structure, improved thermal stability and hydration properties, and a significant increase in soluble DF content from 1.85% to 3.91%. To evaluate the physiological effects, hyperlipidemic mouse models were established and subjected to dietary interventions utilizing okara and fermented okara to measure changes in physicochemical parameters, gut microbiota composition, and lipid metabolism. The dietary intervention was effective, particularly in the fermented okara group, showing a 7.3% weight loss, improved blood lipids (triglycerides: ‒39.8%, total cholesterol: ‒12.8%, low-density lipoprotein cholesterol: ‒34.2%, high-density lipoprotein cholesterol: +26.2%), and a 22.2% lower liver index. Gut microbiota analysis revealed that fermented okara positively modulated the microbial community by increasing the abundance of beneficial bacteria (e.g., Bacteroidota) and reducing the abundance of obesity-associated bacteria (e.g., Bacillota). Lipid metabolism profiling further demonstrated that fermented okara downregulated harmful lipids (e.g., (O-acyl)-ω-hydroxy fatty acids, ceramides, and diacylglycerols) while upregulating beneficial phospholipids (e.g., phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, lysophosphatidylinositol and lysophosphatidic acid). This study highlights a novel approach for enhancing DF utilization through fermentation, providing valuable insights into strategies for preventing obesity and metabolic diseases.