Research on the Extraction Process of Pu-erh Tea Polysaccharide by Response Surface Analysis

[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.

Structure variety and its effects on biological activity of tea polysaccharides

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.

Selenium-enriched and ordinary green tea extracts prevent high blood pressure and alter gut microbiota composition of hypertensive rats caused by high-salt diet

High-salt diet is well recognized as a risk factor for hypertension,and dietary intervention plays a critical role in the prevention of hypertension.The current study investigated the effects of selenium-enriched green tea(Se-GT)and ordinary green tea(GT)on prevention of hypertension of rats induced by high-salt diet,as well as their potential regulatory and mechanism.Our results showed that GT and Se-GT supplementations significantly prevented the increase of blood pressure(BP),activated the phosphoinosmde-3-kinase/protein kinase B(PI3K/Akt)signaling pathway,and regulated the gene expression related to BP,as well as improved the tissue damage like heart,liver,and kidneys.Besides,the key parameters associated with oxidative stress,inflammation and endothelial dysfunction were also altered by GT and Se-GT treatments.Importantly,GT or Se-GT administration adjusted the diversity and composition of the intestinal flora.Moreover,GT and Se-GT supplementations increased the abundance of beneficial bacteria and reduced the abundance of harmful or conditional pathogenic bacteria.More specifically,GT intake specifically and significantly enriched the relative abundance of Paraprevotella and Bacteroides,whereas Se-GT was characterized by specific and significant enrichment for Allobaculum and Bifidobacterium.Our results proved that dietary supplement of GT and Se-GT remarkably improved the vascular functions and effectively prevented tissue damage by regulation of intestinal flora,and thus preventing hypertension induced by high-salt diet.

Fermentation characteristics and probiotic activity of a purified fraction of polysaccharides from Fuzhuan brick tea

Polysaccharides from Fuzhuan brick tea(FBTPS),one of most important bioactive components in tea,showed various health-promoting functions.Our previous work demonstrated that the crude FBTPS(CFBTPS)could modulate the gut microbiota.However,which purified fraction in CFBTPS contributing to the modulation of gut microbiota remains unclear.Thus,the fermentation characteristics and probiotic activity of a purified fraction(FBTPS-2-1)of CFBTPS were evaluated in this work.The results showed that gut microbiota could utilize FBTPS-2-1 to produce short-chain fatty acids including acetic,propionic,n-butyric and n-valeric acids.FBTPS-2-1 could modulate the structure and metabolic pathways of gut microbiota.FBTPS-2-1 could increase the health-promoting gut microbiota such as Prevotellaceae and Bifidobacteriaceae,and decreased the harmful bacteria such as Enterobacteriaceae and Fusobacteriaceae.The results of metagenomics showed that Prevotella copri and Megamonas funiformis were the dominant bacteria after fermentation of FBTPS-2-1.Furthermore,FBTPS-2-1 could regulate the biosynthesis and metabolism pathways of gut microbiota.Thus,the enrichment of food with FBTPS-2-1 is expected as a potential strategy for promoting human health due to modulation of gut microbiota.

Optimization of Extraction Process of Yingshan Cloud Tea Polysaccharides by Response Surface Methodology

[Objectives] This study was conducted to explore the optimal process conditions for hot water extraction of polysaccharides from Yingshan cloud tea. [Methods] Based on single factor experiments, with the extraction rate of polysaccharides as the response value and liquid-to-solid ratio, extraction temperature and extraction time as investigation factors, the optimum extraction process for tea polysaccharides from Yingshan cloud tea was determined by Box-Behnken central componse design and response surface analysis method. [Results] Under the conditions of the liquid-to-solid ratio of 50∶1(ml/g), the extraction temperature at 94 ℃ and the extraction time of 210 min, the extraction rate of polysaccharides from Yingshan cloud tea reached 2.16%. [Conclusions] This study will provide theoretical basis and reference for subsequent related research.

Research on Strategies for the Development of Selenium-enriched Tea in Ankang City of Shaanxi Province in the Context of Targeted Poverty Alleviation

As an important symbol of agricultural and sideline products in Ankang City,selenium-enriched tea affects the development of regional agricultural and sideline industries.In this paper,the development status and problems of the selenium-enriched tea products of Ankang were analyzed in terms of capital,technology,management and sales mode.This research is of positive significance to the development of selenium-enriched products and other agricultural and sideline products of health value,and plays a very important role in promoting the cultivation of village-level characteristic industries and the effective realization of targeted poverty alleviation.

Optimization of Supercritical Fluid Extraction of Tea Flower Polysaccharides by Using Response Surface Method

Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employed to obtain the best possible combination of extraction time,pressure,temperature and ethanol content of modifier for maximum production.The optimum conditions were as follows:extraction time of 170 min,pressure of45 MPa,temperature of 75 ℃,and 50% aqueous ethanol solution as modifier.Under these conditions,the experimental yield was 6.56 ± 0.37%,which was similar to the value predicted by the model.Monosaccharide composition of TFPS was fucose,rhamnose,arabinose,xylose,galactose,glucose,mannose,fructose,ribose,galacturonic acid and glucuronic acid in a molar percent of 31.69,0.21,0.49,1.29,35.82,0.97,1.63,18.34,7.88,1.06 and 0.63.Compared to other extraction methods,SFE could achieve higher yield and gain more types of monosaccharide.

Green tea polysaccharide conjugates and gelatin enhanced viability of L. acidophilus by layer-by-layer encapsulation

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.

Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC

[Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide. [Method] Pu-erh tea polysaccharide was extracted using the wa- ter extraction method, further isolated and purified by DEAE cellulose-52 columns. The obtained tea polysaccharide and four components TPS1, TPS2, TPS3 and TPS, were first derived by 1-phenyl-3-methyl-5-pyrazolone （PMP）, and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatog- raphy （HPLC）. [Result] Pu-erh tea polysaccharide contained eight kinds of monosac- chaddes （mannose, rhamnose, glucuronic acid, galacturonic acid, grucose, galactose, arabinose, fucose）, without xylose; so it was the same with TPS1; each of TPS2, TPS3 and TPS4 contained seven monosaccharides, while no fucose. [Conclusion] This method is simplified and rapid, which can be used to determine the monosac- charide composition of Pu-erh tea polysaccharide and monosaccharide content.

武夷岩茶酸性茶多糖对2型糖尿病大鼠胆汁酸的调节作用机制

[目的]研究从武夷岩茶黄片中提取的一种酸性茶多糖对高血糖大鼠胆汁酸的影响。[方法]通过体外试验评价茶多糖对胆酸盐的结合能力;通过液质联用仪测定大鼠盲肠内容物中胆汁酸组成,并检测大鼠肝脏、胰腺的胆汁酸受体法尼醇X受体FXR、G蛋白偶联胆汁酸受体TGR5 mRNA的相对表达量;Western Blot法检测结肠组织胰高血糖素样肽-1的表达水平。[结果]茶多糖对结合型和游离型的胆酸盐均有一定的结合能力,并且对结合型胆酸盐具有更好的结合能力,当茶多糖质量浓度为2.00 mg/mL时,其对胆酸钠的结合率仅为同浓度下甘氨胆酸钠和牛磺胆酸钠结合率的57.59%,62.62%。茶多糖的干预对大鼠盲肠内容物中胆汁酸水平的影响主要表现为初级胆汁酸鹅去氧胆酸水平的增加,以及次级胆汁酸脱氧胆酸、石胆酸水平的降低。此外,其对大鼠肝脏、胰腺胆汁酸受体FXR、TGR5的mRNA表达具有上调作用;对胰高血糖素样肽-1表达水平无显著性影响。[结论]茶多糖干预可改变大鼠初级胆汁酸/次级胆汁酸的比率,而疏水性更高的次级胆汁酸在肠肝循环中吸收性更差。

响应面法优化乌龙茶提取茶多糖的工艺研究

以乌龙茶为原料,选用回流法提取茶多糖,根据Plackett-Burman实验设计考察提取温度、提取时间、提取次数、料液比等多种因素对茶多糖提取率的影响;在单因素实验基础上,运用Box-Behnken实验设计进行响应面剖析.实验结果显示,当提取温度100℃、提取时长80 min、料液比1∶50时,乌龙茶茶多糖的提取率显著增加,得率是6.13%.对最佳提取工艺开展验证,结果显示实测均值与模型估计值相近,表明该提取工艺平稳可行.

茶成分对肠道菌群的调控作用及其健康效应的研究进展

茶是世界上最受欢迎的健康饮料之一,富含茶多酚、茶多糖、茶色素和茶皂素等多种生物活性成分,对人体健康具有重要影响。肠道是一个复杂而稳定的生态系统,肠道微生态与人体健康密切相关。肠道菌群是茶成分发挥生理调节作用和健康效应的主要作用靶点,本文对近年来几种重要茶成分对肠道菌群的调节作用及其对机体健康的影响相关研究进展进行了综述。茶成分主要通过靶向肠道菌群调节糖代谢和脂代谢,减轻炎症和肠道损伤,缓解情绪和记忆障碍以及调节昼夜节律,发挥其健康效应。阐明茶成分调控肠道菌群的内在作用机制将为更好地利用茶产品来改善肠道微生态,促进人体健康提供科学依据。

茶功能成分的提取方法及其抗运动性疲劳研究进展

茶功能成分主要包括茶多酚、茶氨酸、茶生物碱、茶多糖等,属于抗运动性疲劳的食源性物质。对茶功能成分的提取方法及其抗运动性疲劳作用机制进行阐述,综述了利用水提、有机溶剂提取、微波提取、超声波提取、离子交换、超临界流体提取等方法提取茶功能成分的研究成果,以及茶功能成分对调解机体代谢、清除自由基、增强抗氧化作用、增强骨骼肌抗运动性疲劳作用的研究进展,为开发以茶为原材料的抗运动性疲劳食源性衍生品提供依据。

基于高产胞外粗多糖的白灵芝发酵茶培养基配方优化

为探究白灵芝在液体茶基质上分泌胞外粗多糖的最佳营养条件及其影响因素,本研究在单因素实验的基础上,通过正交试验和方差分析,优化了该菇在茶培养基上胞外粗多糖形成的营养条件,并采用相关性与通径分析,探究了其液体培养特性与胞外粗多糖分泌的关系。结果表明,在马铃薯50 g/L、葡萄糖40 g/L、红土3 g/L、普洱茶20 g/L、茶粉颗粒大小0.075 mm的茶培养基上,白灵芝的胞外粗多糖产量最高(1.49±0.33 g/L)且受各营养条件的影响顺序为葡萄糖>茶叶种类>红土>马铃薯>茶粉颗粒大小。此外,该菇胞外粗多糖的分泌受发酵液可溶性固形物、菌球数量的影响显著,其中前者对其间接影响最大,后者对其直接作用与综合作用最大。总之,茶培养基的营养条件(种类、浓度、颗粒大小等)与白灵芝的液体培养特性对其胞外粗多糖的分泌影响较大且存在交互作用,上述结果可为该菇多糖的提取及功能性食品的开发提供理论参考。

姑辽茶粗多糖提取工艺优化及其免疫调节活性评价

为探究姑辽茶粗多糖的最佳提取工艺并对其免疫活性进行评价。以姑辽茶为原料,固定超声功率400 W,在探究超声时间、提取温度、提取次数、料液比对姑辽茶粗多糖得率的影响的基础上,通过Box-Behnken响应面法对提取工艺参数进行优化;采用CCK-8法检测姑辽茶粗多糖对RAW264.7小鼠巨噬细胞增殖活性的影响,测定TNF-α、IL-6和NO的分泌水平以评价其免疫调节活性。结果表明:在超声时间32 min、提取温度64℃、提取4次、料液比1:44 g/mL的工艺条件下提取的姑辽茶粗多糖得率最高,为13.12%±0.11%;姑辽茶粗多糖中的总糖含量为61.8%±0.09%。姑辽茶粗多糖对RAW264.7小鼠巨噬细胞增殖活性影响作用微弱,基本无毒性作用,在50~400μg/mL范围内对促进RAW264.7小鼠巨噬细胞分泌TNF-α、IL-6和NO呈现一定的量效关系。通过对姑辽茶粗多糖的最佳提取工艺优化及评价其免疫活性,为更好地挖掘姑辽茶多糖资源提供科学依据。

油茶籽壳多糖超声辅助提取工艺优化及抗氧化活性分析

旨在为开发利用油茶籽壳多糖提供基础,以油茶籽壳为原料,通过单因素试验结合响应面法对超声辅助提取多糖的工艺条件进行优化,并对超声辅助提取油茶籽壳多糖(CFP-U)的理化性质(分子质量、单糖组成、傅里叶变换红外光谱、紫外光谱、微观结构)和体外抗氧化活性(羟自由基、超氧阴离子自由基和ABTS+自由基清除率)进行了测定。结果表明:CFP-U的最优超声辅助提取工艺条件为超声时间20min、超声功率650W、液料比40∶1,在此条件下油茶籽壳多糖的得率为(3.28±0.06)%;高效凝胶渗透色谱分析表明,CFP-U的纯度较高,分子质量为91.6kDa;高效液相色谱分析表明,CFP-U的单糖由平均摩尔比为0.05∶0.14∶0.05∶1.00∶0.05∶0.30∶0.35∶0.41的甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖和岩藻糖构成;红外光谱表明,CFP-U存在α-糖苷键、β-糖苷键和吡喃糖环;紫外全波长扫描表明,CFP-U中基本不含蛋白质;扫描电子显微镜观察发现,CFP-U呈不规则形态,为片状结构,表面光滑;体外抗氧化活性测定表明CFP-U能有效清除羟自由基、超氧阴离子自由基和ABTS+自由基,并在一定浓度范围内呈剂量效应关系,且抗氧化活性优于传统热水法提取的油茶籽壳多糖。综上,采用超声辅助法可以有效提取油茶籽壳多糖,且油茶籽壳多糖具有较强的体外抗氧化能力。

康普茶细菌纤维素的形成途径及其在废弃茶叶资源高效利用中的应用

废弃茶叶资源和夏秋茶用于生产康普茶和细菌纤维素,不仅有助于减少环境污染和资源浪费,还能开发高市场价值的产品。细菌纤维素作为一种高晶度、可再生的多糖,广泛应用于生物医疗、环保包装、纺织、新能源电池、护肤品等领域。综述了近年来细菌纤维素膜的应用研究,重点分析了不同发酵环境和茶叶种类对细菌纤维素膜品质的影响,证实了通过调整发酵参数可获得具有特定结晶结构的纤维素。进一步探讨了茶叶成分在菌膜形成中的作用,并提出了提高康普茶细菌纤维素膜产量和质量的新思路。文章强调了康普茶细菌纤维素膜的保健功效及其在可持续产品开发中的重要作用,并指出了进一步研究以促进其工业化应用的必要性。

超微粉碎联合超声波辅助提取鸭屎香单枞茶多糖工艺及活性研究

[目的]提高茶多糖的提取得率。[方法]采用超微粉碎技术对鸭屎香单枞茶进行前处理,利用超声波辅助结合正交试验对其多糖提取工艺进行优化,并考察鸭屎香单枞茶多糖的抗氧化和抑菌活性。[结果]最优提取条件为提取时间150 min、提取温度70℃、提取2次和料液比(g/mL)1∶30,在该提取条件下,鸭屎香单枞茶多糖的平均提取得率达到6.72%。体外抗氧化结果得出,鸭屎香单枞茶多糖对ABTS+和DPPH自由基均具有较强的清除作用,其清除率变化趋势与茶多糖浓度呈正相关;体外抑菌活性研究表明,茶多糖对4种菌株均具有抑制作用,且对大肠杆菌表现出较好的抑制效果,其最低抑菌浓度为3.125 mg/mL。[结论]茶多糖的提取工艺简单,得率高,抗氧化活性好,为鸭屎香单枞茶多糖的进一步研究及新产品开发提供理论依据和重要参考。

六堡砖茶多糖制备及其免疫调节活性

目的:优化六堡砖茶多糖提取工艺,并进一步研究其免疫调节作用及其可能的调节机制。方法:采用单因素实验探究提取温度、料液比及乙醇浓度对茶多糖得率的影响,在此基础上与响应面试验相结合,对茶多糖提取工艺进行了优化。通过测定六堡砖茶多糖对RAW264.7细胞的吞噬能力及NO释放量,检测核因子κB(Nuclear factor-κB,NF-κB)和AMP依赖的蛋白激酶(AMP-dependent protein kinase,AMPK)信号通路相关基因及蛋白表达,评价纯化后的茶多糖的体外免疫调节活性。结果:六堡砖茶多糖的最佳提取工艺为:提取温度91.11℃,料液比1:15.45(g/mL),乙醇浓度82.84%(v/v)。在此条件下,茶多糖得率为8.62%。细胞实验显示六堡砖茶多糖可显著增强RAW264.7细胞的吞噬能力及NO释放量(P<0.05),显著激活NF-κB和AMPK信号通路(P<0.05),显著上调诱导型一氧化氮合成酶(Inducible nitric oxide synthase,iNOS)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素-6(Interleukin-6,IL-6)、白细胞介素-1β(Interleukin-1β,IL-1β)的mRNA表达水平(P<0.05)。其中,高剂量茶多糖效果更佳。结论:通过优化提取温度、料液比及乙醇浓度条件,可有效提高六堡砖茶多糖得率,并可通过激活NF-кB/AMPK通路发挥免疫调节作用。该研究结果为六堡砖茶多糖活性深入探究和应用提供了研究基础。

单丛茶多糖的表征及其体外降糖降脂活性研究

目的探究单丛茶多糖的理化性质及其体外降糖降脂活性。方法以制得的单丛茶多糖为原料,采用苯酚-硫酸法、咔唑-硫酸法检测其糖占比情况,采用DEAE-52色谱柱分析其多糖组成情况,通过紫外光谱、傅里叶变换红外光谱、热重-差热分析对其进行初步表征,通过扫描电镜观测其表面形貌,再通过测定其对α-葡萄糖苷酶,胰脂肪酶抑制率及体外胆酸盐结合能力,评价其体外降糖、降脂活性。结果该茶多糖的中性糖占比为(33.51±0.29)%,酸性糖占比为(47.39±0.47)%,DEAE-52色谱分离在洗脱剂NaCl溶液浓度0.9 mmol/L时出现一个主要峰,说明该茶多糖是一种酸性多糖。该多糖是以α构型的糖苷键连接的吡喃型糖环,且其中无核酸类和蛋白类杂质。热重-差热分析表明该多糖热稳定性较好。扫描电镜观测显示其为不规则片状结构,表面光滑且结构紧密。其与牛磺胆酸盐、甘氨胆酸盐和胆酸盐的结合率分别是(24.08±0.30)%、(8.30±0.70)%和(7.66±0.60)%,分别相当于阳性对照考来烯胺结合率的85.71%、31.58%和25.86%。其对α-葡萄糖苷酶和胰脂肪酶的抑制作用,最高分别达到了81.76%、61.16%,显示出较好的抑制效果。结论本研究获得的单丛茶多糖是一种酸性多糖,具有较好的体外降糖、降脂活性,在功能性食品及医疗保健领域具有良好应用前景。