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.

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.

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.

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.

Phenolic compounds participating in mulberry juice sediment formation during storage

The stability of clarified juice is of great importance in the beverage industry and to consumers.Phenolic compounds are considered to be one of the main factors responsible for sediment formation.The aim of this study is to investigate the changes in the phenolic content in clarified mulberry juice during storage.Hence, separation, identification, quantification, and analysis of the changes in the contents of phenolic compounds, both free and bound forms, in the supernatant and sediments of mulberry juice, were carried out using high performance liquid chromatographic system, equipped with a photo-diode array detector（HPLC-PDA） and HPLC coupled with quadrupole-time of flight mass spectrometric（HPLC-QTOF-MS/MS） techniques.There was an increase in the amount of sediment formed over the period of study.Total phenolic content of supernatant, as well as free phenolic content in the extracts of the precipitate decreased, whereas the bound phenolic content in the sediment increased.Quantitative estimation of individual phenolic compounds indicated high degradation of free anthocyanins in the supernatant and sediment from 938.60 to 2.30 mg/L and 235.60 to 1.74 mg/g, respectively.A decrease in flavonoids in the supernatant was also observed, whereas the contents of bound forms of gallic acid, protocatechuic acid, caffeic acid, and rutin in the sediment increased.Anthocyanins were the most abundant form of phenolics in the sediment, and accounted for 67.2% of total phenolics after 8 weeks of storage.These results revealed that phenolic compounds, particularly anthocyanins, were involved in the formation of sediments in mulberry juice during storage.

Differential responses of weaned piglets to supplemental porcine or chicken plasma in diets without inclusion of antibiotics and zinc oxide

This study was conducted to investigate the effects of spray-dried porcine plasma protein(SDPP)or spray-dried chicken plasma protein(SDCP)supplementation in diets without the inclusion of antibiotics and zinc oxide(ZnO)on growth performance,fecal score,and fecal microbiota in early-weaned piglets.A total of 192 healthy weaning piglets(Duroc×Landrace×Yorkshire,21 d old)were blocked by BW(6.53±0.60 kg)and randomly assigned to 4 dietary treatments:negative control(NC,basal diet),positive control(PC),basal diet+ZnO at 2 g/kg and antibiotics at 0.8 g/kg,SDPP(containing 5%SDPP),and SDCP(containing 5%SDCP).The experiment lasted 14 d.The SDPP group had higher(P<0.05)final BW,average daily gain and average daily feed intake than the NC and SDCP groups.The percentage of piglets with fecal scores at 2 or≥2 was higher(P<0.05)in the NC and SDCP groups than in the PC group.A decreased(P<0.05)bacterial alpha diversity and Bacteroidetes abundance,but increased(P<0.05)Firmicutes abundance were observed in the PC and SDPP groups when compared to the NC group.The relative abundance of Lactobacillus was higher(P<0.05)in the SDPP than in the SDCP group,and that of Streptococcus was higher(P<0.01)in the PC and SDPP groups than in the NC group.The PC group also had higher(P<0.01)Faecalibacterium abundance than the NC and SDCP groups.Additionally,the SDCP group had higher(P<0.05)serum urea nitrogen than those fed other diets,and lower(P<0.10)shortchain fatty acids to branched-chain fatty acids ratio than the PC and SDPP groups.Overall,SDPP was a promising animal protein for piglets in increasing feed intake,modifying gut microbiota profile,reducing gut protein fermentation and alleviating diarrhea frequency,thus promoting growth performance,under the conditions with limited in-feed utilization of antibiotics and ZnO.