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.     

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.     

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.     

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.     

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.     

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.     

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.     

Tea Consumption and Antihypertensive Effects

Tea consumption is a major source of flavanoids for a wide large population.Any physiological effects of tea,like antihypertension,could have a significant impact on population health.The effects of tea on blood pressure are less consistent.Results of population studies and long term controlled studies are consistent with a blood pressure-lowering effect of tea.However,some of the short-term intervention trials,mainly in normotensive individuals,have not demonstrated significant blood pressure reduction with tea.The focus of this review is on the mounting evidence from human studies that tea can lower blood pressure.     

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.     

Tea Seed and Its Bioactive Functions

Tea seed is a byproduct in tea production and also a source of nutritional and bioactive compounds.There have been studies showing that extracts of tea seeds offered many physiological functions including anti-inflammatory,anti-oxidant,anti-tumor,anti-obesity,hepatoprotective and gastroprotective effects.The tea seed oil is also an acceptable biodiesel and the saponin-rich tea seed meal can be used as vermicide to expel earthworms from the soil of golf courses and sports fields.The bioactive functions of tea seed extracts and their potential uses in agricultural and industrial sectors were reviewed in the present paper.     

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.     

Tea Breeding in Japan

Tea breeding in Japan started around 116 years ago,and to date,more than 110 cultivars have been developed and released.Seedling plants were uprooted and rapidly replaced with new clonal cultivars after 1970.At present,more than 95％ of the tea gardens in Japan grow improved clonal cultivars.Although the cultivation of the ＂Yabukita＂ variety had expanded and contributed to approximately 76％ of the tea grown,this excessive plantation resulted in some serious problems in the cultivation and management of the tea industry after 1990.Therefore,after 2000,new programs have been initiated to breed superior varieties through the use of various genetic resources and DNA markers.     

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.     

Yuexiang Longjing Tea and Its Quality Characteristics

Shengzhou is a major tea producing county in China and the major tea produced in Shengzhou is Yuexiang Longjing tea.Environment and tea cultivar are two important factors influencing tea quality.Chemical composition of tea samples prepared using materials from cultivars ‘Zhenong-117＇ and ‘ Baiye-1＇ were investigated.It showed that concentrations of total amino acids and catechins were more than 4.4％ and 129 mg/g respectively,suggesting that Yuexiang Longjing had a good quality potential.     

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.     

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.     

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.     

Benefits of Daily Intake Tea on Human Health

The recent research achievements about the mechanisms of beneficial health effects of tea polyphenols and the epidemiological investigation on anti-cancer,anti-cardiovascular diseases,and anti-obesity through tea consumption were reviewed.It is proved that reactive oxygen species is the main reason to induce cell mutation,DNA damage,obesity,high blood pressure and many kinds of cancers.Tea catechins and theaflavins have excellent bioactivity on scavenging ROS due to their characteristic structure feature of phenolic hydroxyl group,which means drinking tea could prevent diseases.Epidemidogical investigations also showed that tea consumption could reduce the risk of lung cancer,gastric cancer,bladder cancer,and so on.However,the frequency of tea drinking or tea consumption amounts significantly affected the prevention efficiency.The epidemiologic investigations also find that drink green tea,especial black tea is useful to modify the cardiovascular diseases.In vivo and vitro tests showed that tea supplement could moderate the metabolism of blood lipid and prevent obesity.These indicated that tea and tea extracts might reduce the risk of many diseases.