Antibacterial mechanism of kojic acid and tea polyphenols against Escherichia coli O157:H7 through transcriptomic analysis

Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.

Anti-skin aging effects and bioavailability of collagen tripeptide and elastin peptide formulations in young and middle-aged women

Background:Collagen peptides(CP),including tripeptides and elastin peptides(EP),are known for their in vitro and in vivo anti-skin aging effects.Despite positive results in animal models,the combination effects of CP and EP and the bioavailability of CP in human studies,particularly in young and middle-aged women,remain underexplored.Objective:To evaluate the effects of an orally administered collagen drink combining CP and EP on the skin health of young and middle-aged women.Materials and Methods:A single-center,randomized,double-blind,parallel-controlled trial was conducted,utilizing the WONDERLABR fish collagen tripeptide beverage.Participants consumed the drink over an 8-week period.Results:Compared to the placebo group,the collagen drink group showed significant improvements in skin hydration(39.19%increase),transepidermal water loss(33.45%decrease),skin elasticity(25.37%increase),dermal collagen content(21.64%increase),pore size(7.94%decrease),wrinkle length(18.09%decrease),skin smoothness(2.85%improvement),and skin roughness(15.32%decrease).Overall pore volume decreased by 60%,and visual assessments indicated a decrease in skin luminosity by 15.20%and smoothness index by 22.55%.Mass spectrometry demonstrated a significant increase in collagen efficacy components,including blood pH and GPH levels(P<0.05).Conclusion:The study confirmed the combination nourishing and anti-skin aging effects of EP and CP on the skin of young and middle-aged women,demonstrating significant improvements in various skin parameters and good bioavailability of collagen peptides.

Metabolic profiles and morphological characteristics of leaf tips among different sweet potato(Ipomoea batatas Lam.)varieties

Sweet potato leaf tips have high nutritional value,and exploring the differences in the metabolic profiles of leaf tips among different sweet potato varieties can provide information to improve their qualities.In this study,a UPLC-Q-Exactive Orbitrap/MS-based untargeted metabolomics method was used to evaluate the metabolites in leaf tips of 32 sweet potato varieties.Three varieties with distinct overall metabolic profiles(A01,A02,and A03),two varieties with distinct profiles of phenolic acids(A20 and A18),and three varieties with distinct profiles of flavonoids(A05,A12,and A16)were identified.In addition,a total of 163 and 29 differentially expressed metabolites correlated with the color and leaf shape of sweet potato leaf tips,respectively,were identified through morphological characterization.Group comparison analysis of the phenotypic traits and a metabolite-phenotypic trait correlation analysis indicated that the color differences of sweet potato leaf tips were markedly associated with flavonoids.Also,the level of polyphenols was correlated with the leaf shape of sweet potato leaf tips,with lobed leaf types having higher levels of polyphenols than the entire leaf types.The findings on the metabolic profiles and differentially expressed metabolites associated with the morphology of sweet potato leaf tips can provide useful information for breeding sweet potato varieties with higher nutritional value.

Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus

Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.

The role of probiotics in prevention and treatment of food allergy

With the prevalence of food allergy increasing every year,food allergy has become a common public health problem.More and more studies have shown that probiotics can intervene in food allergy based on the intestinal mucosal immune system.Probiotics and their metabolites can interact with immune cells and gut microbiota to alleviate food allergy.This review outlines the relationship between the intestinal mucosal immune system and food allergy.This review also presents the clinical application and potential immunomodulation mechanisms of probiotics on food allergy.We aim at providing a reference for further studies to explore the key active substances and immunomodulation mechanisms of anti-allergic probiotics.

Enzymatic hydrolysis of silkworm pupa and its allergenicity evaluation by animal model with different immunization routes

Silkworm pupa is a nourishing food with high nutritional value,but its consumption has been greatly limited given its allergenicity.Enzyme hydrolytic technique is recognized as an effective method to reduce the allergenicity of protein.In this study,we aimed to investigate the effect of enzymolysis on the allergenicity of silkworm pupa.Crude silkworm pupa protein was extracted through alkali extraction and acid precipitation,which included 5 proteins with the molecular weights ranging from 34 kDa to 76 kDa,and silkworm pupa were then hydrolyzed by alkaline protease.The allergenicity of silkworm pupa protein and its enzymatic hydrolysates was evaluated by establishing BALB/c mice model,and the mice were immunized via intragastric gavage and intraperitoneal injection,respectively.The results indicated that the intraperitoneal inj ection immunization route induced more by detecting with antibodies,histamine and Th2-related cytokines.Moreover,mice treated with silkworm pupa protein peptide displayed no obvious allergic symptoms,indicating that enzyme hydrolytic technique could significantly reduce the allergenicity of silkworm pupa.

Evaluation of allergenic protein profiles in three Chinese high-oleic acid peanut cultivars using NanoLC-Orbitrap mass spectrometry

High oleic-acid peanuts are known for their pre-longed shelf-life and health benefit due to high content of oleic fatty acid.However,the allergenicity and allergenic protein profiles in Chinese high-oleic peanuts have yet to be studied.For this purpose,an Orbitrap Fusion mass spectrometry(MS)-based method that is feasible for identification of putative allergenic protein as well as semi-quantitation of five major allergen protein in three different Chinese high-oleic peanut cultivars(JH 13,JH 16 and JH 18)have been reported.Results show that three Chinese high-oleic acid peanut cultivars selected all contained highly allergenic proteins Ara h1,Ara h 2,Ara h 3 and Ara h 6.The allergenic protein profiles of Chinese high-oleic acid peanut cultivars were very similar to that of conventional peanuts,but the allergenic protein subunits varied greatly among higholeic peanuts.Additionally,a comprehensive peptide-filtering pipeline had been developed for identification of potential peptide markers in peanut allergen proteins.Through the peptide-filtering pipeline,three novel peptide markers,IVQIEAKPNTLVLPK,SSNPDIYNPQAGSLR and AQSENYEYLAFK surrogate to Ara h 1,Ara h 3 with high abundance,good MS response and highly reliability were identified,which can be used as candidate peptide markers for the detection of peanut allergens in different food matrices.

Insights into the relations between cell wall integrity and in vitro digestion properties of granular starches in pulse cotyledon cells after dry heat treatment

Natural foods,such as whole pulses,are recommended in the dietary guidelines of the US and China.The plant cell wall structure in whole pulses has important implications for the nutritional functionalities of starch.In this study,garbanzo bean cells with varying degrees of cell wall integrity were subjected to dry heat treatment(DHT)and used to elucidate the food structure-starch digestion properties of pulse food.The morphological features suggested that all cell samples do not exhibit remarkable changes after being subjected to DHT.Molecular rearrangement and the crystallite disruption of starch granules entrapped in cells occurred during DHT as assessed by the crystal structure and thermal properties.DHT decreased the inhibitory effects of enzymes of both the soluble and insoluble components,but the digestion rate and extent of slightly and highly damaged cell samples did not exhibit significant differences compared with their native counterparts.We concluded that the starch digestion of pulse cotyledon cells is primarily determined by the intactness of the cellular structure.This study reveals the role of food structure on the ability to retain the desirable nutritional properties of starch after subjection to physical modification.

Effects of heat treatment on the structure, digestive property, and absorptivity of holoferritin

Ferritin,as an iron storage protein,has been considered to be a well-utilized iron supplement.However,the typical thermal processing of food rich in ferritin may affect the structure and function of ferritin as an iron supplement.Here,a plant ferritin(soybean seed ferritin,SSF)and an animal ferritin(donkey spleen ferritin,DSF)were used to analyze the changes in fundamental structure and iron content after thermal treatments(68°C for 30 min,100°C for 10 min).Then,SSF and DSF after thermal treatment were administered intragastrically to mice to further evaluate its digestive stability and absorptivity after thermal processing.Results showed the secondary structure,oligomeric states,iron content,and digestive stability of DSF were maintained better than that of SSF after thermal treatments,indicating that DSF has a higher thermostability than SSF.Both SSF and DSF after thermal treatment exhibited higher absorptivity than untreated ferritins.SSF showed higher absorptivity than DSF whether heated or not.

Correlation Between Antioxidation and the Content of Total Phenolics and Anthocyanin in Black Soybean Accessions

The objective of this study was to investigate the correlations between antioxidations and the contents of the total phenolics and anthocyanin in 127 accessions of black soybean. A T-test, a fast clustering procedure, and a correlation coefficient analysis were used for experimentation. The variation ranges of the total antioxidant capacity （TAC）, the total phenolics, and anthocyanin contents in 127 black soybean accessions were 0.44-3.56, 7.05-74.82, and 0.22-1.87 mg g-l, respectively, displaying significant genotype differences. The major differences in TAC, the total phenolics, and the anthocyanin contents existed among various types of accessions from geographical regions. The differences between the accessions from black and yellow soybeans, spring and autumn, summer and autumn, Dongbeichun and Nanfangchun, Dongbeichun and Nanfangxia, Beifangchun and Nanfangchun, and Beifangchun and Nanfangxia were significant at 0.01 or 0.05 levels, respectively. The general tendency was that the TAC, the total phenolics, and the anthocyanin contents of Beifangchun accessions were higher than that of Dongbeichun ones, while that of Nanfangchun accessions were the worst. 127 black soybean accessions could be clustered into 6 clusters, which consisted of 3, 24, 20, 31, 37, and 12 accessions, respectively. The most significant （P 〈 0.01） correlations existed respectively between the TAC and the total showed that the total substances phenolics content, and the TAC and the anthocyanin content of black soybean. The results phenolics and anthocyanin in black soybean seed coat were the important antioxidation

Separation, Purification and Identification of Antioxidant Compositions in Black Rice

To separate, purify and identify the antioxidative compositions of black rice, using total antioxidation capacity （TAC） as an activity-monitoring parameter, different fractions of black rice antioxidative extracts were obtained using solvents of different polarities such as petroleum ether, chloroform, ethyl acetate and normal butyl alcohol. The main anfioxidative components were separated from the strongest antioxidative fractions by using Sephadex LH-20 resin and the structures were analyzed by ultraviolet-vis, infra-red, ESI-MS, ^1H-NMR and ^13C-NMR spectrums. Results showed that the water fraction and normal butyl alcohol antioxidafive extract fraction of black rice had the strongest antioxidation capacities and their TACs reached 383 and 392 ku g^-1, respectively. Four main antioxidative components were separated from the water fraction and their TACs reached 976, 878, 1 134 and 1087 ku g^-, respectively. The spectroscopy analysis indicated that the four active components of the antioxidative extract of black rice were four anthocyanin compounds of malvidin, pelargonidin- 3, 5-diglucoside, cyaniding-3-glucoside and cyaniding-3, 5-diglucoside. It is concluded that the anthocyanin compounds are the most important substantial foundations for antioxidation.

Approaches to evaluate nutrition of minerals in food

Numerous techniques have been developed to determine the bioavailability of minerals.Each method has specific detection objects with certain procedures to assure the results.This review focuses on a comprehensivecomparison of the applications,advantages,and critical control points of these techniques.The commonly used approaches for assessing mineral bioavailability can be divided into three categories-chemical methods,in vitro models and in vivo tests.Chemical methods are first developed,and mainly simulating the digestion environment to give a rough prediction of mineral bioavailability.In vitro models mainly used different cells to simulate the process and environment of food digestion to assess the availability of minerals.In vivo tests are employing complex models to observe the bioavailability of minerals after complicated digestive process in animal models or human volunteers.This review summarizes the critical points of establishment of these relevant models,compares the advantages and limitations among three categories.Although no single bioavailability method is ideal for all micronutrients,certain methods under proper operation can indeed be employed to minimize the differences between simulated results and reality for effective evaluation of the bioavailability of minerals.

Effect of the degree of milling on the physicochemical properties,pasting properties and in vitro digestibility of Simiao rice

Simiao rice is a variety of long-grain Indica rice popular in South China.However,researches on the milling technology of Simiao rice are limited.The effect of different degrees of milling(DOMs)of Simiao rice(0-12%)were evaluated in terms of the physicochemical properties and in vitro starch digestibility of the rice.The results showed that,as the DOM increased from 0 to 12%,the head rice yield(HRY)and the content of protein,lipid,dietary fiber,vitamin B1,vitamin E and niacin nonlinearly decreased,while the content of total starch and amylose and paste viscosity parameters nonlinearly increased.The differences in chemical constituents between the brown and milled Simiao rice with different DOMs lead to the variation in their pasting properties and in vitro digestibility.Because of lower content of slowly digestible starch(SDS)and resistant starch(RS),milled Simiao rice exhibited greater digestibility and a higher estimated glycaemic index(EGI).The EGI of Simiao rice ranged from 77.98 to 85.55,and remained almost constant(approximately 84)when the DOM was above 4%.Correlation analysis indicated that the EGI had strong negative correlations with lipid,protein,dietary fiber and RS,but a positive correlation with amylose.These results provide theoretical guidance for the production of Simiao rice with desired physicochemical properties and digestibility by adjusting the DOM.

Catalytic Activity of Iridium Dioxide With Different Morphologies for Oxygen Reduction Reaction

Iridium dioxide with different morphologies(nanorod and nanogranular) is successfully prepared by a modified sol-gel and Adams methods. The catalytic activity of both samples for oxygen reduction reaction is investigated in an alkaline solution. The electrochemical results show that the catalytic activity of the nanogranular Ir O2 sample is superior to that of the nanorod sample due to its higher onset potential for oxygen reduction reaction and higher electrode current density in low potential region. The results of Koutecky-Levich analysis indicate that the oxygen reduction reaction catalyzed by both samples is a mixture transfer pathway. It is dominated by four electron transfer pathway for both samples in high overpotential area, while it is controlled by two electron transfer process for both samples in low overpotential area.

Antioxidations and Their Correlations with Total Flavones and Anthocyanin Contents in Different Black Rice Varieties

The antioxidations and their correlations with total flavones and anthocyanin contents in different black rice varieties were studied. The results indicated that the great differences in total antioxidant capacity （TAC）, scavenging free radical capacity （SFRC）, total flavones and anthocyanin contents existed among 242 black rice varieties. Comparisons of TAC, SFRC, total flavones and anthocyanin contents of different black rice types showed that the differences between black rice and white rice, indica one and japonica one, and nonglutinous one and glutinous one were significant at 0.01 levels, respectively. This showed that the TAC, SFRC, total flavones and anthocyanin contents of japonica type were higher than those of indica one, and nonglutinous type were higher than glutinous one. According to the fast clustering procedure, 242 black rice varieties could be clustered into 10 clusters, 184 indica rice varieties into 10 clusters, and 58 japonica rice varieties into 6 clusters. Most significant （P〈0.01） correlations existed between TAC and total flavones and anthocyanin contents, and between SFRC and total flavones and anthocyanin contents of black rice, respectively. This showed that the antioxidation of black rice was closely correlated with its active compositions of flavones and anthocyanin.

Linear Regression Relationship between Lychee Juice Content and Buffering Capacity

Juice drinks are an important commercialization alternative for lychee, a tropical and subtropical fruit. Although the lychee juice content is important when assessing the quality of a drink, there are no published methods to determine it, particularly simple ones for the routine inspection of juice drinks. Lychee juice drinks contain ingredients with buffering capacity including proteins and ions such as phosphate, citrate, lactate, carbonate, acetate and propionate. The relationship between their buffering capacity and lychee juice content was studied. Citric acid was added to pure lychee dilutions in distilled water containing 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% and 10% lychee juice. The pH of the dilutions was measured to obtain a linear model for the molar H+ concentration as a function of the added citric acid (g/L) amount LC = (BC-494.2)/12,031, where LC was the lychee juice content and BC was defined as the juice buffering coefficient.

Stability of a type 2 diabetes rat model induced by high-fat diet feeding with low-dose streptozotocin injection

Objective： The present study aims at determining the stability of a popular type 2 diabetes rat model induced by a high-fat diet combined with a low-dose streptozotocin injection. Methods： Wistar rats were fed with a high-fat diet for 8 weeks followed by a one-time injection of 25 or 35 mg/kg streptozotocin to induce type 2 diabetes. Then the diabetic rats were fed with regular diet/high-fat diet for 4 weeks. Changes in biochemical parameters were monitored during the 4 weeks. Results： All the rats developed more severe dyslipidemia and hepatic dysfunction after streptozotocin injection. The features of 35 mg/kg streptozotocin rats more resembled type 1 diabetes with decreased body weight and blood insulin. Rats with 25 mg/kg streptozotocin followed by normal diet feeding showed normalized blood glucose level and pancreatic structure, indicating that normal diet might help recovery from certain symptoms of type 2 diabetes. In comparison, diabetic rats fed with high-fat diet presented decreased but relatively stable blood glucose level, and this was significantly higher than that of the control group（P〈0.05）. Conclusions： This model easily recovers with normal diet feeding. A high-fat diet is suggested as the background diet in future pharmacological studies using this model.

Dietary chenodeoxycholic acid improves growth performance and intestinal health by altering serum metabolic profiles and gut bacteria in weaned piglets

Nutritional diarrhea and subsequent performance degradation in weaned piglets are major challenges for the pig industry.Bile acids(BA)can be added to the diet as emulsifiers.This experiment was conducted to investigate the effects of chenodeoxycholic acid(CDCA),a major primary BA,on growth performance,serum metabolic profiles and gut health in weaned piglets.A total of 72 healthy weaned piglets were randomly assigned to the control(CON)and the CDCA groups,which were feed a basal diet and the basal diet supplemented with 200 mg/kg CDCA for 30 d,respectively.Our results demonstrated that CDCA significantly increased final BW and average daily gain(ADG),decreased feed-to-gain(F:G)ratio and tended to reduce diarrhea incidence.In addition,CDCA increased the villus height-to-crypt depth(V:C)ratio,elevated goblet cell numbers and the expression of tight junction proteins,suggesting the enhancement of intestinal barrier function.As an emulsifier,CDCA increased jejunal lipase activity and the mRNA expression of pancreatic lipases.CDCA supplementation also altered the serum metabolic profiles,including increasing the levels of indole 3-acetic acid,N'-formylkynurenine and theobromine that were beneficial for gut health.Moreover,the relative abundance of 2 beneficial gut bacteria,Pre-votella 9 and Prevotellaceae TCG-001,were increased,whereas the relative abundance of a harmful bacteria,Dorea,was decreased in the gut of weaned piglets supplemented with CDCA.Importantly,the altered serum metabolic profiles showed a strong correlation with the changed gut bacteria.In conclusion,CDCA improved the growth performance of weaned piglets by improving intestinal morphology and barrier function,and enhancing lipid digestion,accompanied by alterations of serum metabolic profiles,and changes in relative abundance of certain gut bacteria.

Chemical Constituents from Roots of Millettia speciosa

Objective To study the chemical constituents from the roots of Millettia speciosa.Methods The chemical constituents were isolated and purified by silica gel, Sephadex LH-20, and ODS column chromatography. The structures were identified by means of spectral data. Results Fifteen compounds were isolated and identified as naringenin（1）, liquiritigenin（2）, garbanzol（3）, 7-hydroxy-6,4′- dimethoxyisoflavone（4）, calycosin（5）, 2′,5′,7-trihydroxy-4′-methoxyisoflavone（6）, 2′-hydroxybiochanin A（7）, 6-methoxycalopogonium isoflavone A（8）, demethylmedicarpin（9）, 4,4′-dihydroxy-2′-methoxychalcone（10）, 2′,4′-dihydroxy-4-methoxychalcone（11）, rhododendrol（12）, secoisolariciresinol（13）, bisdihydrosiringenin（14）, and polystachyol（15）. Conclusion All compounds are obtained from this plant for the first time.

Structural identification and antioxidant potency evaluation of pomelo vinegar polyphenols

Polyphenols are the main antioxidant ingredient of honey pomelo vinegar.However,the antioxidant contributions of various individual phenolics to total polyphenols and antioxidant mechanism are unclear.In this study,phenolic compounds were identified,and the antioxidant potency and antioxidant contribution of individual phenolics were analyzed.The antioxidant mechanism was also studied in HepG2 cells.A total of seven phenolics were identified,including naringin,narirutin,rhoifolin,vanillic acid,methyl hesperidin,vicenin-2,and ferulic acid;among which,ferulic acid had the highest extracellular antioxidant potency,while methyl hesperidin had the lowest.Without considering the synergistic effect of the phenolics,naringin,ferulic acid,and vicenin-2 were major contributors to the antioxidant potency of pomelo vinegar polyphenols(PVP)using four antioxidant assays.PVP at the concentrations of 20μg/mL and 100μg/mL had a protective effect against H_(2)O_(2)-induced oxidative damage to HepG2 cells.PVP also reduced lactic dehydrogenase(LDH)release and reactive oxygen species(ROS)accumulation in cells.The western blotting results revealed that PVP promoted translocation of NFE2-related factor 2(Nrf2)from the cytoplasm to the nucleus and up-regulated the expression of its governed antioxidant enzymes such as NAD(P)H:quinone oxidoreductase 1(NQO1),heme oxygenase-1(HO-1),glutathione S-transferase A2(GSTA2),and glutamate-cysteine ligase catalytic subunit(GCLC).In summary,PVP could serve as a potential therapeutic agent for oxidative stress-related disorders.