Studies on Umami Taste of Tea

Umami is one of the five basic tastes and an important taste attribute of green tea.Amino acids are major components contributing to umami taste and the top three amino acids in tea are theanine,glutarnic acid and aspartic acid.Trace of umami taste components adenosine monophosphate （AMP） and guanosine monophosphate （GMP） were detected in tea.Levels of umami taste components varied with tea cultivar,environmental conditions,fertilizer and processing method.The taste threshold of amino acids differentiated greatly and its DOT （dose over threshold） is an important indicator evaluating its contribution to umami taste.     

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.     

Study on the Retention Rate of Green Tea Catechins Components and Tea Polyphenol by Different Processing Technology

The aim of this research was to explore the effect of fixation,rolling,and drying processing technology on the retention rate of green tea catechins components and tea polyphenol.Different fixation processes （rotary drum-firing,microwave,steam-blasting）,rolling process （weight of rolling,gently press rolling and traditional rolling）,drying process （stove drying,roasting dehydration,baked fried drying） were adopted.The effect of different tea processing technology on the retention rate of catechins component and tea polyphenol was analyzed.It showed that the microwave fixation process,gently press rolling process,baked fried dry process were beneficial to keep high levels of EGCG,C,EGC,EC,ECG.     

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.     

Applications of Green Tea Extract in Bakery Products

Green tea extract （GTE） is a rich source of tea catechins with antioxidative,anticarcinogenic and antiarteriosclerotic activities and it has been applied in food such as bakery products to provide health benefits and extend the shelf life.This review outlines the stability of green tea catechins during baking process of bakery products supplemented with GTE and the effects of GTE on the functional properties,sensory properties,physical characteristics and Maillard reaction of bakery products.     

The 30-Day Oral Administration Studies of Liposoluble Tea Polyphenols in Rats

Tea polyphenols is a natural antioxidant with a variety of biological activity.However,the weak liposolubility and low bioavailability limit their application.As a result,structural modification of tea polyphenols comes into being.The prepared liposoluble tea polyphenols was suggested as a good candidate antioxidant for edible-oil and fats products.But,safety studies on liposoluble tea polyphenols are limited.The objective of the present study was conducted to synthesize liposoluble tea polyphenols and evaluate its toxicity in Sprague-Dawley rats on oral administration at dietary levels of 1,2 and 4％ for 30 days.There were no adverse effects on general condition,growth,food intake,feed conversion efficiency,haematology parameters,clinical chemistry values and organ weights.High-dose males exhibited a higher haemoglobin concentration and a lower alanine aminotransferase levels,and high-dose females showed a lower albumin and globulin levels.These slight changes were considered of no toxicological significance.Necropsy and histopathology findings revealed no treatment-related changes in any of the organs.Thus,the results allowed us to conclude that the liposoluble tea polyphenols properly utilized in the oral administration could be devoid of any toxic risk.     

Functional Components of Tea （Camellia Sinensis） Germplasms Collected in Korea

This study was carried out to obtain useful information and to search quality related components for breeding of tea by analysis of Korean local tea leaves at Sulloc-Cha R＆D center in Jeju Island,Korea.It was also conducted to measure the major agronomic characteristics of 300 local germplasms.These results allowed us to select some superior lines as genetic resources for green-tea breeding and research genotypes.     

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℃.     

Physicochemical Properties and Functional Compounds of Commercial Green Tea Seed Oil

Physicochemical properties of green tea seed oil including cold test,color,flash point,gravity,refraction index,moisture content,acid value,iodine value,unsaponifiable matter and saponification value were investigated.Fatty acid composition and catechin content of the oil was determined by GC and HPLC analysis.The oil is stable at low temperature.High flash point （267.8 ± 5.1 ℃） showed the high thermal stability of green tea seed oil as well,which support for suitability to use as cooking oil.Specific gravity and refraction index of green tea seed oil was found as 0.913 and 1.4679,respectively.Color of the oil was measured as 99.7 ±0.2 for lightness,1.9 ± 0.1 for greenness and 6.6 ± 0.1 for yellowness.Acid value （KOH mg/ml）,iodine value,unsaponifiable matter （％） and saponification value of green tea seed oil were 0.21,104.1,0.11 and 215,respectively.Fatty acids compositions of green tea seed oil was found to be dominated by oleic acid （81.3％） and presence of minor amount of linoleic acid （4.8％）,palmitic acid （4.6％）,palmitoleic acid （3.3％）,linolenic acid （3.2％） and stearic acid （1.0％）.The presence of antioxidative compounds such as （-）-epicatechingallate （207.2 ±0.2 g/g） and （-）-epigallocatechin gallate （99.5 ±0.6 g/g） in the oil could enhance its shelf life during storage.     

Characteristics of Superfine Green Tea Powder and Its Application in Food Industry

Superfine green tea powder is a new kind of tea product that can be eaten directly.It provided most of the benefits of whole green tea leaves,with all of the bioactive ingredients.This paper highlighted the characteristics and health benefits of superfine green tea powder,and its applications in food industry.     

Effects of Tannic Acid on Active Aluminum Species Distribution in Various Tea Soils

Effects of tannic acid on active aluminum species distribution in different pH tea soils in Yunnan and Jiangxi tea gardens were studied by field observation and laboratory analysis.There were 4 species of active aluminum in the tea soil,i.e.,exchangeable aluminum Al3＋,unimer hydroxyl aluminum Al（OH）2＋ Al（OH）2＋,acid-soluble aluminum Al（OH）30 and humic-acid aluminum Al-HA.Experimental results showed that tannic acid at levels 0 ～0.4 mmol/kg and 0 ～ 2.0 mmol/kg,with the rising of soil pH value,the content of exchangeable aluminum decreased significantly,hydroxyl aluminum,acid-soluble aluminum and humic-acid aluminum were increased gently.When the concentration of tannic acid increased to above 2.0 mmol/kg,the inhibition of higher concentration of tannic acid on content of active aluminum was strengthened with the rising of soil pH value and variation law of 20 ～40 cm soil layer was similar to 0 ～20cm soil layer.Generally speaking,the content of active aluminum in upper layer of soil were more than subsoil and total content of active aluminum in Yunnan tea soils were higher than Jiangxi tea soils.The correlation analysis showed that the soil pH were positively correlated with hydroxyl aluminum,humic-acid aluminum,pHBC （r =0.796,0.960,0.852 ; p ＜ 0.01,0.01,0.01） in 0 ～ 20 cm soil layer.pHBC were significant negative correlated with exchangeable aluminum （r =-904,p ＜ 0.01）,hydroxyl aluminum （r =-645,p ＜ 0.05）,and with humic-acid aluminum have a positive correlation,correlation coefficient was0.795 （P ＜ 0.05）.Meanwhile,the tannic acid addition concentration were 0 ～ 0.4 mmol/kg soils pH were increased significantly,while samples attains a peak pH value afterwards decrease continuously,the relationship between the pH and the concentration of tannic acids accords with the equation：YpH =-0.04CDN ＋3.82（R2 =0.95,P ＜0.01）.When the concentration of tannic acid up to about 8.0 ～ 12.0 mmol/kg,soil pH keep unchanged.Therefore,we can clearly draw that effects of tannic acid on active aluminum content of the inflection point is not the same in different region of tea garden soil.Low concentration tannic acid can improve the soil content of various forms of aluminum,but with the increase in the amount of tannic acid,the various forms of aluminum content are inhibited.With the soil pH increased,high concentrations tannic acid on the inhibition of the release of active aluminum increased.pH and tannic acid on the total amount of active aluminum garden soil was mutual weakening effect relationship.     

Effects of Soil Characters on the Tea Quality in the Tea Region of Qin-Ba Mountain,Hubei Province,PR China

Based on the analysis of physical and chemical properties of soil,nutrient elements and biochemical compositions of tea leaves,the relationship between soil characters and tea quality was studied.The results showed that soil total phosphorus,potassium,available potassium,copper and zinc were the main factors which affected and limited the content of nutrient elements of tea leaves.Furthermore,soil pH,organic matter,total nitrogen,potassium,exchangeable calcium,magnesium,available copper and zinc were the main factors affecting and limiting the content of biochemical compositions in tea leaves.Tea quality could be improved by controlling these soil factors.     

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.     

Tea Art Education for Elementary School Students in Hangzhou City of Zhejiang Province in China——A Case of Caihe Second Elementary School

Caihe Second Elementary School,a public school in Hangzhou city of Zhejiang province in China,has shown excellent performance at practicing tea art education for students as a part of after-school activities it encourages.In this paper,the author figured out significance of tea art in Chinese society by discussing ＂why elementary students learn Chinese tea art＂ through observation on tea art education at Caihe Second Elementary School and interview with persons involved.     

Practice-based Research on Popularity of Tea Culture in Northern Mountainous Area and Improvement of Students＇ Humanism Spirit

In this paper,questionnaires about college tea culture and humanism spirit have been investigated in the undergraduates of Hebei Agricultural University in mountainous area of Northern China.After analyzing the survey results and the causes,the author made references and gave recommendations to the university students about the tea culture and humanism spirit cultivation.     

Discussion and Evaluation of How ＂Tea Culture＂ is Defined

The essence of tea culture stems from the meeting of tea＇s inherent morality,its roots in nature,and human cultural activity.Because it is intertwined with traditional philosophy,Chinese tea culture is well-established and flourishing.The definitions and delineations of tea culture are varied,but any definition should reflect tea culture＇s relativity in space and time and human-centered nature,especially the spiritual needs of humans.     

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.     

Effect of Different Drying Methods on the Volatile Compounds Jinmudan Oolong Tea

Jinmudan,a new tea variety from Fujian Province has an excellent quality with a unique aroma like magnolia frogrance.To monitor the changes in the tea volatile compounds during the Jinmudan Oolong tea manufacturing （drying） process,the volatiles of tea samples were extracted and analyzed.Characteristic volatile compounds in Jinmudan Oolong tea were nerolidol,α-famesene,linolenic acid,palmitic acid,indole,phenylacetaldehyde,cisjasmone,β-phenylethanol,etc.The content of nerolidol was the highest in four tested samples.The composition of the volatile compounds in microwave drying sample was simple,but its concentration was high,in which the main volatile compounds were alcohols and esters.The processing with combination of traditional drying craft and modem aroma-improvement technique could obviously improve the tea aroma,especially in level of epoxy linalool and jasmine lactone.