Effects of Brewing Conditions on Quality of Pu＇erh Tea Infusion

To brew tea correctly is very important to absorb the tea nutrition for people.The dynamic changes of the main compositions in brewing Pu＇erh tea processing with different conditions were studied.Three different temperatures and eight times were designed to study the effects on the tea infusion quality.The index t0.5 min （50％ concentration of compounds in tea infusion） was used to evaluate the extract speed of compound in this experiment.The results showed that caffeine solubility speed at 80℃ was the highest to compare with tea polyphenols,amino acid,caffeine,soluble sugar,theaflavins and theabrownine,t0.5min of caffeine was 4.8 min,amino acid 10.3min was the second,the third one was tea polyphenols,soluble sugar was the lowest.We also found in different infusion temperature the t0.5min of compounds was distinguishing.With increasing the temperature all t0.5min of six compounds were shorter.However,the change regulations of t0.5min for all compounds in 90℃ and 100℃ were similar to in 80℃.Total quality score （TQS） were applied to evaluate the quality of tea infusion.The results found the TQS score of infusion was higher with the temperature rising,and the temperature to brew best quality infusion was 100℃ for 4-5min.According to the multiple regression analysis between sensory assessments and chemical components of Pu＇erh tea we suggested the TQS was mainly affected by theaflavins,amino acid,soluble sugar and theabrowine four factors in 100℃.     

Effect of Drinking Green Tea on Mental State of Humans

Tea is one of the most widely consumed beverages in the world,among which green tea is most common in China and Korea.Green tea constituents possess a great value to human health wherein lots of clinical studies and investigations were conducted by researchers and experts.However,there are still increasing demands and interest on the health properties of green tea,especially its effects on mental state of human brains.Based on the collated clinical studies,green tea was used to improve mental alertness and thinking.Thus,higher consumption of green tea was associated with a lower prevalence of cognitive impairment.This review summarizes the effects of drinking green tea on the mental state of human brains.Green tea contains a unique set of L-theanine and epigallocatechin gallate （EGCG） that possess biological activities in antioxidant,anti-memory loss,and antiproliferative assays potentially relevant to the prevention and treatment of various forms of brain damage.Theanine in green tea may play a role in reducing stress.The use of highly innovative method of reading and mental behavior of the human brain＇s response with the intake of green tea thru neuroimaging was also covered in this review.     

The Beauty of Elegance ‘Pungnyu＇ in the Tea Culture of Korea

‘Tea culture＇ broadly includes ‘providing tea＇,‘ the tea ceremony＇,‘ tea ritual＇,‘ tea artistry＇ and ‘ tea party＇.The concept of ‘Pungnyu＇ in Korea was proposed by Choi Chi-won （857 ～ 894？）,who pointed out that ＂there is a profound truth ‘ Tao＇ in Korea,which was considered to be ‘ Pungnyu＇ or the beauty of elegance.The origin of ‘Pungnyu＇ can be traced back to the history of hermits.‘Pungnyu＇ includes the teachings of Buddhism,Confucianism and Taoism.     

Tea Culture and Tea Consumption Trends in Australia

Tea is a large part of modem Australian culture with its British origins.Australians drink tea and have afternoon tea and morning tea much the way the British do.Tea was introduced to Australia through eolonisation by the British.In fact,tea was aboard the First Fleet in 1788.Tea was the staple drink and considered a necessity,even when other items were scarce.Much of the time tea drinking is not the delicate,refined cultural expression that the rest of the world imagines-like a more formal tea ceremony.Tea is usually black tea served with milk with or without sugar.Strong tea served with lots of milk and often two teaspoons of sugar.Even very slightly formal events can be a cause for cups and saucers to be used instead of mugs.For most people,a cup （or commonly a mug） of tea is something drink very often.     

Analysis of the Volatile Chemicals of Longjing Tea from Different Production Locations Using Electronic Nose

Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.     

Fluoride in Tea and Its Risk Assessment

Tea plant absorbs from soil a large amount of fluorine （F） which is accumulated in leaf,resulting in elevated F concentration in tea.It is a controversial topic whether the fluoride in tea is associated with fluorosis.The research advances in F variation of various kinds of tea,factors influencing F level in tea and the associated health risk assessment were reviewed in the present paper.The F level in tea increases with the maturity of the tea leaf.Brick tea had a high F content because it was prepared using mature shoots and old tea leaves as raw material.Some low grade UK supermarket economy teas contained elevated F comparable to the Chinese brick tea.Tea F level is also affected by tea cultivar,soil condition,tea processing method and tea infusion preparation method.     

A Study of Historical References of Korean Royal Court Tea Culture through the Periods of Three Kingdoms,Goryeo Kingdom and Joseon Dynasty

The tea culture of royal court has a special significance as it represents the culture of the nation.The tea culture of Korean royal court has been described in various historical documents including the Memorabilia of Three Kingdoms,the History of Goryeo,and the Chronology of Joseon Dynasty.These historical documents indicate an increasing sophistication of royal court tea culture as the use of tea became expanded through the periods of Three Kingdoms,Goryeo Kingdom and Joseon Dynasty.The tea was offered during ancestral and religious rituals; served as ceremonial drinks; and offered to guests in ceremonial manners.The procedures of these tea ceremonies were ritualized and codified to properly reflect decorum and propriety of the royal court.This paper examines historical references of royal court tea culture of Korea over the periods of Three Kingdoms,Goryeo Kingdom and Joseon Dynasty.Findings from this paper can promote further research on the development of royal court tea culture in Asian countries.     

A Study on Effects of Turn-over Technology on the Quality of Jinmudan Oolong Tea

This paper reported the effect of oolong tea processing procedure of turn-over on quality of the Jinmudan Oolong tea,including taste components and volatile compounds.The content of the water extractable solids was gradually increased,but the content of amino acid decreased and then increased,and the content of the soluble sugar and tea polyphenols increased after the first turn-over processing.The major volatiles of the three tested Jinmudan Oolong tea samples were nerolidolcistrans,α-farnesene,palmitic acid,indole and 9,12,15-octadecatrienoicacid and methyl ester.The sensory evaluation results showed that an appropriate increase in the number of turn-over was helpful to quality of the Jinmudan Oolong tea.     

Purine Alkaloids and their Metabolism in Camellia Sinensis and Related Species简

Caffeine,theobromine and theophylline are the major purine alkaloids found in Camellia sinensis.Theacrine was detected in a special Chinese tea plant named kucha （Camellia kucha）.With tracer experiments,the metabolism pathway of these purine alkaloids has mostly been explored.The isolation and cloning of the genes encoding enzymes in the related pathway made it possible to develop methods to control caffeine level in tea products via transgenic technique.Further study on the kucha species would be helpful to obtain materials for processing naturally caffeine-less tea.However,there is still a long way to go in this direction such as sensory improvement of products prepared using leaves of kucha.     

A Study on Physiological Character of Fresh Tea Leaves in Different Cold-Resistant Varieties简

In order to reveal the cold resistant mechanism of tea plant,two varieties with different cold resistances were studied.The activities of catalase （CAT）,peroxidase （POD）,superoxide dismutase （SOD） and polyphenol oxidase （PPO） were investigated,and the contents of soluble protein,sugar and malondialdehyde （MDA） were determined in fresh tea leaves in the autumn.The results showed that the activities of POD and the content of soluble sugar were both much higher in the variety with strong cold resistance,and the content of soluble protein was associated with the cold resistance,while the cold resistance of the plant was not related with the activities of the CAT,SOD and PPO,and the content of MDA.It is considered that the activity of POD and contents of soluble sugar could be used as indicators to identify the cold resistance of tea varieties.