[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including ext...[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including extraction temperature, ex- traction duration and solid-liquid ratio, on the extraction yield of tea polysaccharide. Box-Behnken central composite design and response surface methodology were adopted to determine the optimal extraction process of Pu-erh tea polysaccharide. [Result] The results of response surface analysis showed that the optimal extraction process was solid-liquid ratio of 1：17, extraction temperature of 80 ℃ and extraction duration of 78.5 min, and the Pu-erh tea polysaccharide yield was 12.72%. [Conclu- sion] Using response surface methodology （RSM） is feasible for the optimization of Pu-erh tea polysaccharide extraction process, and the tea polysaccharide yield increased significantly.展开更多
Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coa...Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coagulant,anti-obesity and immunomodulatory effect.The biological effectiveness of TPSs has direct relation with their structures such as monosaccharide composition,molecular weight,glycosidic linkages,conformation and others,which can be influenced by tea materials,processing methods,extraction and purification procedures among others.Comparing to the study of tea polyphenols,the exploration of TPSs in structural elucidation and biofunctionality is very preliminary.Yet several factors affecting the structural change of TPSs have been studied and identified.Consequently,the variation of some TPS biological activity brought by the change of TPS structures has been evaluated and preliminary correlation of structure activity relationship of TPSs has been performed.Therefore,this review aims to serve as a summary research report regarding the influencing factors on TPSs structures and consequential effects on the biological activities of TPSs.We hope to provide updated information and systematic references for future study and functional food development of TPSs.展开更多
Adverse environments such as the gastrointestinal tract can affect the efficacy of probiotics.Therefore,the adequate protection of probiotics and their total effect exertion are probiotics application research hotspot...Adverse environments such as the gastrointestinal tract can affect the efficacy of probiotics.Therefore,the adequate protection of probiotics and their total effect exertion are probiotics application research hotspots.Green tea polysaccharide conjugate(gTPC),an anionic polymer,and gelatin as the encapsulation materials,and layer-by-layer self-assembly technology as the method,were applied to encapsulate Lactobacillus acidophilus.Microscopic results showed that with the increase in the number of deposited layers,the encapsulation was more complete.After continuous exposure to simulated gastrointestinal fluid for 120 min,the survival rate of unencapsulated cells was 53.26%,and encapsulated cells with different deposited layers were 66.00%,71.99%,76.94%,and 79.89%,respectively.In addition,Gel/gTPC bilayers can efficiently improve cell thermotolerance and freezing resistance.Results indicated that the more the number of Gel/gTPC bilayers,the more significant the protection is.Therefore,gTPC and Gel are viable materials to protect probiotics through microencapsulation by Layer-by-layer self-assembly.展开更多
Fuzhuan brick tea(FBT),a uniquely microbially fermented dark tea,is known for its diverse health-promoting properties.This study aimed to elucidate the detailed structure of the predominant acidic polysaccharide from ...Fuzhuan brick tea(FBT),a uniquely microbially fermented dark tea,is known for its diverse health-promoting properties.This study aimed to elucidate the detailed structure of the predominant acidic polysaccharide from FBT and to evaluate antioxidant potential both in vitro and in vivo.The crude FBT polysaccharide(CFBTP)was extracted with ultrasonic assistance,and its main acidic fraction(FBTP-A)was purified to obtain a homogeneous fraction,designated as FBTP-A1.Structural analysis revealed FBTP-A1 to be a low-molecular-weight(15.12 kDa)pectic polysaccharide with a methyl esterification degree(DM)of~24.9%and an HG/RG-I ratio of 3.45,composed of 46.97 mol%1,4-α-D-galacturonic acid(GalA),along with 5.43 mol%1,2-α-L-rhamnose and 5.65 mol%1,2,4-α-L-rhamnose residues as backbone residues.Arabinan,galactan,and arabinogalactan side chains were found attached to the C4 position of 1,2,4-α-L-rhamnose in rhamnogalacturonan-I(RG-I)domains.In vitro,CFBTP demonstrated superior radical-scavenging activity compared to the purified FBTP-A1,likely due to synergistic effects from associated phenolics and proteins.In vivo experiments using Caenorhabditis elegans showed that FBTP fractions extended lifespan,improved resistance to oxidative and thermal stress,and upre-gulated the activities of superoxide dismutase(SOD)and catalase(CAT).These findings advance our under-standing of FBTPs as promising natural antioxidants and support their potential development as functional food ingredients.展开更多
Tea polyphenols(TP)and tea polysaccharides(TPS)are the two main hypoglycemic substances in tea.While the hypoglycemic activities of TPS and TP have been extensively reported,there remains a paucity of evidence regardi...Tea polyphenols(TP)and tea polysaccharides(TPS)are the two main hypoglycemic substances in tea.While the hypoglycemic activities of TPS and TP have been extensively reported,there remains a paucity of evidence regarding their synergistic regulation of hypoglycemic function.In this study,water-soluble polysaccharides and cell wall polysaccharides were firstly prepared from Yichang roasted green tea using sequential extraction method.Different types of tea polysaccharides,especially tea cell wall polysaccharides,exhibited diverse chemical compositions,molecular structures,and biological activities.The tea cell wall polysaccharides extracted with 4M NaOH(p4M-TPS)exhibited the highest inhibitory activity against different glycosidases.Furthermore,TPS(p4M-TPS)and TP(Epigallocatechin gallate,EGCG)were combined in different proportions to assess their hypoglycemic effect on hyperglycemic mice,and p4M-TPS-TP1:2 exhibited the most pronounced effect in promoting the expression of the TGR5/GLP-1 pathway to exert the synergistic anti-diabetic potential.This study firstly purified and characterized tea cell wall polysaccharide,and explored its potential hypoglycemic activity,thereby providing a valuable reference for the development of natural hypoglycemic functional products originating from tea active ingredients and their combinations,indicating the synergistic effect of tea active ingredients rather than just a single active ingredient.展开更多
基金Supported by National Science and Technology Support Program of China (2007BAD58B03)~~
文摘[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including extraction temperature, ex- traction duration and solid-liquid ratio, on the extraction yield of tea polysaccharide. Box-Behnken central composite design and response surface methodology were adopted to determine the optimal extraction process of Pu-erh tea polysaccharide. [Result] The results of response surface analysis showed that the optimal extraction process was solid-liquid ratio of 1：17, extraction temperature of 80 ℃ and extraction duration of 78.5 min, and the Pu-erh tea polysaccharide yield was 12.72%. [Conclu- sion] Using response surface methodology （RSM） is feasible for the optimization of Pu-erh tea polysaccharide extraction process, and the tea polysaccharide yield increased significantly.
基金supported by Hubei Science and Technology Plan Key Project(G2019ABA100)Assessment and Comprehensive Utilization of Characteristic Biological Resources in Dabie Mountains(4022019006)Natural Science Fund of Hubei Province(2019CFB395)。
文摘Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coagulant,anti-obesity and immunomodulatory effect.The biological effectiveness of TPSs has direct relation with their structures such as monosaccharide composition,molecular weight,glycosidic linkages,conformation and others,which can be influenced by tea materials,processing methods,extraction and purification procedures among others.Comparing to the study of tea polyphenols,the exploration of TPSs in structural elucidation and biofunctionality is very preliminary.Yet several factors affecting the structural change of TPSs have been studied and identified.Consequently,the variation of some TPS biological activity brought by the change of TPS structures has been evaluated and preliminary correlation of structure activity relationship of TPSs has been performed.Therefore,this review aims to serve as a summary research report regarding the influencing factors on TPSs structures and consequential effects on the biological activities of TPSs.We hope to provide updated information and systematic references for future study and functional food development of TPSs.
基金This research was financially supported by the National Natural Science Foundation of China(grant number 31871813).
文摘Adverse environments such as the gastrointestinal tract can affect the efficacy of probiotics.Therefore,the adequate protection of probiotics and their total effect exertion are probiotics application research hotspots.Green tea polysaccharide conjugate(gTPC),an anionic polymer,and gelatin as the encapsulation materials,and layer-by-layer self-assembly technology as the method,were applied to encapsulate Lactobacillus acidophilus.Microscopic results showed that with the increase in the number of deposited layers,the encapsulation was more complete.After continuous exposure to simulated gastrointestinal fluid for 120 min,the survival rate of unencapsulated cells was 53.26%,and encapsulated cells with different deposited layers were 66.00%,71.99%,76.94%,and 79.89%,respectively.In addition,Gel/gTPC bilayers can efficiently improve cell thermotolerance and freezing resistance.Results indicated that the more the number of Gel/gTPC bilayers,the more significant the protection is.Therefore,gTPC and Gel are viable materials to protect probiotics through microencapsulation by Layer-by-layer self-assembly.
基金supported by the National Natural Science Foundation of China(No.U22A20546).
文摘Fuzhuan brick tea(FBT),a uniquely microbially fermented dark tea,is known for its diverse health-promoting properties.This study aimed to elucidate the detailed structure of the predominant acidic polysaccharide from FBT and to evaluate antioxidant potential both in vitro and in vivo.The crude FBT polysaccharide(CFBTP)was extracted with ultrasonic assistance,and its main acidic fraction(FBTP-A)was purified to obtain a homogeneous fraction,designated as FBTP-A1.Structural analysis revealed FBTP-A1 to be a low-molecular-weight(15.12 kDa)pectic polysaccharide with a methyl esterification degree(DM)of~24.9%and an HG/RG-I ratio of 3.45,composed of 46.97 mol%1,4-α-D-galacturonic acid(GalA),along with 5.43 mol%1,2-α-L-rhamnose and 5.65 mol%1,2,4-α-L-rhamnose residues as backbone residues.Arabinan,galactan,and arabinogalactan side chains were found attached to the C4 position of 1,2,4-α-L-rhamnose in rhamnogalacturonan-I(RG-I)domains.In vitro,CFBTP demonstrated superior radical-scavenging activity compared to the purified FBTP-A1,likely due to synergistic effects from associated phenolics and proteins.In vivo experiments using Caenorhabditis elegans showed that FBTP fractions extended lifespan,improved resistance to oxidative and thermal stress,and upre-gulated the activities of superoxide dismutase(SOD)and catalase(CAT).These findings advance our under-standing of FBTPs as promising natural antioxidants and support their potential development as functional food ingredients.
基金financially sponsored by National Key R&D Program of China(2022YFD2101104)National Natural Science Foundation of China(32172223)+1 种基金New Young Teachers Program of Shanghai Jiao Tong University(24X010500154)China Postdoctoral Science Foundation(BX20220201,2021M702140).
文摘Tea polyphenols(TP)and tea polysaccharides(TPS)are the two main hypoglycemic substances in tea.While the hypoglycemic activities of TPS and TP have been extensively reported,there remains a paucity of evidence regarding their synergistic regulation of hypoglycemic function.In this study,water-soluble polysaccharides and cell wall polysaccharides were firstly prepared from Yichang roasted green tea using sequential extraction method.Different types of tea polysaccharides,especially tea cell wall polysaccharides,exhibited diverse chemical compositions,molecular structures,and biological activities.The tea cell wall polysaccharides extracted with 4M NaOH(p4M-TPS)exhibited the highest inhibitory activity against different glycosidases.Furthermore,TPS(p4M-TPS)and TP(Epigallocatechin gallate,EGCG)were combined in different proportions to assess their hypoglycemic effect on hyperglycemic mice,and p4M-TPS-TP1:2 exhibited the most pronounced effect in promoting the expression of the TGR5/GLP-1 pathway to exert the synergistic anti-diabetic potential.This study firstly purified and characterized tea cell wall polysaccharide,and explored its potential hypoglycemic activity,thereby providing a valuable reference for the development of natural hypoglycemic functional products originating from tea active ingredients and their combinations,indicating the synergistic effect of tea active ingredients rather than just a single active ingredient.
