Changes in Polyphenols and Antioxidant Activities of Yingshan Yunwu Tea during Digestion in Vitro

[Objectives]To explore the change rule of polyphenol content and antioxidant activity of coarse old leaves of Yingshan Yunwu Tea in the process of human digestion.[Methods]The coarse and old leaves of Yunwu tea in Yingshan,Huanggang,Hubei Province were selected as the research object,and their digestion in vitro was simulated.The total polyphenol content was determined by Folin-phenol reagent colorimetric method,and the DPPH radical scavenging activity and total antioxidant activity were determined.[Results]After simulated gastrointestinal digestion in vitro,the polyphenol content and antioxidant activity of coarse old leaf tea soup showed a downward trend.After gastrointestinal digestion,the polyphenol content in tea infusion separately decreased by 31.8%and 8.5%;the scavenging rate of DPPH free radical was 97%before digestion,decreased to 92%after gastric digestion and 65%after intestinal digestion,which decreased by 5%and 27%,respectively;after gastrointestinal digestion,the total antioxidant capacity of tea soup decreased by 4.7%and 3.1%,respectively.[Conclusions]This study provided a reference for the development and application of coarse old leaves of Yingshan Yunwu tea,and provided a reference for the nutritional value evaluation and comprehensive utilization of coarse old leaves,so as to make the best use of coarse tea leaves and reduce the waste of resources.

Focusing on the recent progress of tea polyphenol chemistry and perspectives

Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable components.The chemical characterization and physical characteristics of tea polyphenols have been comprehensively studied over the previous years.Still the emergence of new chemistry in tea,particularly the property of scavenging reactive carbonyl species(RCS)and the newly discovered flavoalkaloid compounds,has drawn increasing attention.In this review,we summarize recent findings of a new class of compounds in tea-flavonoid alkaloids(flavoalkaloids),which exist in fresh tea leaves and can be generated during the process of post-harvesting,and also postulate the formation mechanism of flavoalkaloids between catechins and theanine-derived Strecker aldehyde.Additionally,we detail the up-to-date research results of tea polyphenols regarding their ability to trap RCS and their in vivo aminated metabolites to suppress advanced glycation ends products(AGEs).We further raise questions to be addressed in the near future,including the synthetic pathways for the generation of flavoalkaloids and AGEs in fresh tea leaves before processing and the concentrations of tea polyphenols that affect their RCS scavenging capability due to their pro-oxidant nature.More intensive research is warranted to elucidate the mechanisms of action underlying the biological activity of flavoalkaloids and the pharmacological application of tea polyphenols in scavenging RCS and impeding detrimental AGEs.

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.

Multifunctional health-promoting effects of oolong tea and its products

Oolong tea,partially fermented from Camellia sinensis leaves,exhibits significant antioxidative,anti-inflammatory,and anti-cancer activities as indicated in several in vitro and in vivo studies.However,studies on health promoting effects of oolong tea and its characteristic compounds are limited.The potential efficacy of bioactives derived from oolong tea and their roles as promising anticancer agents,their cardio-protective benefits during hypoxic conditions,effects in treating allergic disorders,potential prebiotic activities,improvement of blood lipid status in human beings,effectivity as oral hypoglycemic agent in the treatment of type 2 diabetes,and their potentials to reduce the risk of obesity have been discussed in this review.These promising studies mainly gained from animal studies might broaden the consumption and usage of the phenolic-enriched oolong tea and its products in food and pharmaceutical industries.However,potential health beneficial effects of oolong tea in humans should be further complemented by large-sized,randomized double-blind and placebo-controlled trials to consolidate potential therapeutic applications.

Inhibitory effects of oxyresveratrol on ERK and Smad1/2 phosphorylation and HSC activation in preventing carbon tetrachloride-induced rat liver fibrosis

Oxyresveratrol(ORes,trans-2,4,3′,5′-tetrahydroxy stilbene)naturally exists in mulberry,grapes,peanuts and other plants.It belongs to stilbene polyphenolic family and has an extra hydroxyl group at 2-position comparing with resveratrol(Res).Hence,ORes has stronger antioxidant activity than resveratrol.In present study,we employed a rat hepatic fibrosis model induced by carbon tetrachloride(CCl_(4))and administrated ORes via gavage feeding to study the protective effects and potential mechanisms of ORes against hepatic fibrosis.We demonstrated that rat liver oxidative damage induced by CCl_(4)was significantly alleviated after ORes feeding.Furthermore,the mRNA transcription levels ofα-smooth muscle actinn(˛-SMA),desmin,and two MMPs(MMP2 and MMP9)were reduced and the expression levels of transforming growth factorβ1(TGF-β1),p-small mother against decapen-taplegic protein(Smad)1/2 and p-extracellular signal-regulated kinases(ERK)1/2 in the liver tissue down-regulated dramatically.In a parallel study with Res,ORes showed more efficacious protective effect than Res against rat liver fibrosis,which is attributed to extended conjugation system due to the extra hydroxyl group at 2-position on ORes making it more electron-rich and susceptible to oxidation than Res.Therefore,dietary consumption of mulberry and other fruits containing ORes may be beneficial in the prevention of liver fibrosis.

Development of Whole Potato Flour Fish Noodles

[Objectives] This study was conducted to prepare a kind of traditional aquatic food―fish noodles in Hubei Province by replacing some wheat flour with whole potato flour. [Methods] With whole potato flour, wheat flour and minced fish as main raw materials, the effects of the ratio of whole potato flour to minced fish and the addition amounts of sodium alginate, egg white, salt and ginger juice on the quality of whole potato flour fish noodles were studied. An orthogonal experiment was conducted to confirm the optimal technical formula of the whole potato flour fish noodles. [Results] The best formula of the whole potato flour fish noodles was whole potato flour 30 g, wheat flour 20 g, minced fish(grass carp) 50 g, salt 2.00 g, egg white 4.00 g, sodium alginate 2.00 g, and ginger juice 5.00 g. [Conclusions] The whole potato flour fish noodles prepared according to this formula are not only nutritious and taste good, but also have the advantages of easy and convenient eating and storage. This kind of fish noodle has good development prospects.

Health promoting activities and corresponding mechanism of(–)-epicatechin-3-gallate

(–)-Epicatechin-3-gallate(ECG),a bioactive polyphenolic compound,has contributed a lot to the health benefits of green tea.Great attention has been focused on(–)-epigallocatechin-3-gallate(EGCG),but limited research has been performed towards ECG.Like EGCG,ECG also possesses various pharmacological and physiological properties,such as mediation of antioxidant activities,anti-inflammation response,regulation of cell proliferation and apoptosis,as well as anticancer properties during angiogenesis,invasion and metastasis stages.Nontoxic ECG has various molecular targets within the cells,including CYP enzymes,phaseⅡdetoxification and antioxidant enzymes,as well as pro-inflammatory mediators.The antineoplastic mechanism contains inhibition of phase 1 CYP enzymes,induction of phaseⅡdetoxification and antioxidant enzymes,high anti-inflammatory efficacy,arrest of cell cycle progression,regulation of apoptosis,as well as mediation of metastasis processes.In particular,the gallate moiety of ECG is critical for mediating inhibitory effects towards cancer cells.Besides regulation of intracellular signaling pathways,ECG also inhibits RNase A and matrix metalloproteinase enzymatic activity via chelating metals(copper and zinc)in cancer cells.This review has summarized recent studies on pharmacological properties of ECG,and discussed corresponding mechanism on modulation of cellular signaling events by ECG,hoping to broaden its multiple usage.

Hypoglycemic effects of naturally processed Polygonum multiflorum extract in KK CgAy/J mice and its mechanism of action

In 2021,there are approximately 537 million adults ageing 20-79 years affected by diabetes worldwide and the number is rising rapidly,hence it is important to manage and control diabetes mellitus and its associated complications.Food is one of the key factors in preventing and combating diseases such as diabetes.Both as a food and an herbal medicine,Polygonum multiflorum(PM)has been used as an anti-aging tonic,for hair darkening in traditional Chinese medicine for several centuries.The recent research effort of PM has been focused on antioxidant,anti-ageing and anti-tumor properties.In the present study,we utilized the traditional processing of harvested raw PM,and identified several stilbene components and then evaluated the potential anti-diabetic effects of the processed PM extract(PME).PME(0.075%)was given to diabetic mice(KK CgAy/J)in drinking water and after 7 weeks,PME-treated mice had significantly lower glucose levels than mice in the diabetic control group(P<0.01).The mechanism was explored with ELISA and Western blotting and results suggested that the effect was through maintainingβ-cell function.

Optimization of Conditions of Concentrating Protein in Rapeseed Meal by Ultrasonic-assisted Alcohol Washing

This study was performed to optimize the conditions for concentrating protein in commercial rapeseed meal by ultrasonic-assisted alcohol washing method. The effects of sonication time,particle size,ultrasonic power and liquid to solid ratio on protein content were investigated. The result showed that the optimal conditions for concentrating protein in rapeseed meal were: sonication time of 40 min,particle size of 40 mesh,ultrasonic power of 800 W and liquid to solid ratio of 9∶ 1. Under these conditions,the protein content in rapeseed meal was increased to 55. 47%,which was 10. 43% higher than that in rapeseed meal not treated by sonication.

Immobilization and Properties of Polyphenol Oxidase

[Objectives]This study was conducted to investigate the effects of embedding conditions on activity and catalytic properties of immobilized polyphenol oxidase.[Methods]Polyphenol oxidase was immobilized in a polymer material by the embedding method,and the optimal immobilization conditions were obtained by single factor tests:CaCl_(2) concentration 2.0%,sodium alginate concentration 2.0%,immobilization time 2 h and mass ratio of enzyme to carrier 10 mg/100 g,under which the immobilized enzyme activity was 93.33 U/g.Under the above conditions,the properties of polyphenol oxidase immobilized by sodium alginate(A-PPO)and free polyphenol oxidase were studied.[Results]The thermostability of A-PPO was better than that of the free enzyme,but the pH stability of A-PPO was inhibited.The Michaelis constant K_(m) values of free polyphenol oxidase and A-PPO were 0.37 and 0.48 mmol/L,respectively,and the maximum reaction rate V_(max) values were 0.38 and 0.51 mmol/(L·g),respectively.[Conclusions]This study provides a theoretical basis for the study of the properties of polyphenol oxidase.

Development of a Fubaiju Compound Tea Beverage

[Objectives]This study was conducted to develop a compound tea beverage with local characteristics.[Methods]A chrysanthemum compound tea beverage was developed using Fubaiju and Yunwu tea as the main raw materials,supplemented by wolfberry,through single factor test and orthogonal test,combined with sensory evaluation.[Results]The final product formula was the volume ratio of Fubaiju extract and Yunwu tea extract 2∶1,wolfberry juice 15%,white sugar 4%,citric acid 0.04%,and xanthan gum 0.05%.The prepared compound chrysanthemum tea beverage had the aroma and taste of Fubaiju,Yunwu tea and wolfberry,and tasted good.[Conclusions]This study provides reference for the deep processing and application of the two local special resources,Fubaiju and Yunwu tea.

Study on the Effect of Enzymolysis Condition on the Browning of Chinese Chestnut Serosity

In this study,with chestnut as a raw material,the effects of enzymolysis time,enzymolysis temperature and enzyme amount on hydrolysis process were investigated. The optimal reaction conditions were obtained by single factor and response surface experiment as follows： enzymolysis time of 75 min,enzymolysis temperature at 58 ℃ and enzyme amount of 7 U/g. Under these conditions,the browning degree of chestnut serosity was 1. 228.

CloudRank-D： benchmarking and ranking cloud computing systems for data processing applications

With the explosive growth of information, more and more organizations are deploying private cloud systems or renting public cloud systems to process big data. However, there is no existing benchmark suite for evaluating cloud performance on the whole system level. To the best of our knowledge, this paper proposes the first benchmark suite CloudRank-D to benchmark and rank cloud computing sys- tems that are shared for running big data applications. We an- alyze the limitations of previous metrics, e.g., floating point operations, for evaluating a cloud computing system, and propose two simple metrics： data processed per second and data processed per Joule as two complementary metrics for evaluating cloud computing systems. We detail the design of CloudRank-D that considers representative applications, di- versity of data characteristics, and dynamic behaviors of both applications and system software platforms. Through experi- ments, we demonstrate the advantages of our proposed met- tics. In several case studies, we evaluate two small-scale de- ployments of cloud computing systems using CloudRank-D.