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緑茶
Green tea is a type of tea made from the leaves and buds of the ''Camellia sinensis'' that have not undergone the withering and oxidation process that creates oolong teas and black teas. Green tea originated in China in the late 1st millennium BC, and since then its production and manufacture has spread to other countries in East Asia. Several varieties of green tea exist, which differ substantially based on the variety of ''C. sinensis'' used, growing conditions, horticultural methods, production processing, and time of harvest. While it may slightly lower blood pressure and improve alertness, current scientific evidence does not support most health benefit claims, and excessive intake of green tea extracts can cause liver damage and other side effects. History Tea consumption has its legendary origins in China during the reign of mythological Emperor Shennong. A book written by Lu Yu in 618–907 AD, ''The Classic of Tea'' ( zh, t=茶 經, s=, p=chájīng), is considered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyokuro
is a type of green tea from Japan. It differs from the standard ''sencha'' (a classic green tea grown in the sun) in being grown under the shade rather than the full sun. The name "gyokuro" translates as "jewel dew" (or "jade dew"). According to the Japan Tea Central Association, gyokuro is defined as "a tea manufactured in the same manner as sencha from tea leaves picked from covered tea gardens that are almost completely shaded from sunlight for about 20 days using covering materials such as reed screens, straw, or shading nets, from the time when the new shoots of the first flush start to grow." While most sencha is from the cultivar of ''Camellia sinensis'', gyokuro is often made from a specialized variety such as Asahi, Okumidori, Yamakai, and Saemidori. Most gyokuro is grown in the Fukuoka Prefecture, Fukuoka, Kyoto Prefecture, Kyoto, and Mie Prefecture, Mie prefectures. Gyokuro tea production dates back to the 1830s, when the merchant Yamamoto Kahei discovered some Japan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after India, representing 17.4% of the world population. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land across an area of nearly , making it the list of countries and dependencies by area, third-largest country by land area. The country is divided into 33 Province-level divisions of China, province-level divisions: 22 provinces of China, provinces, 5 autonomous regions of China, autonomous regions, 4 direct-administered municipalities of China, municipalities, and 2 semi-autonomous special administrative regions. Beijing is the country's capital, while Shanghai is List of cities in China by population, its most populous city by urban area and largest financial center. Considered one of six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eisai
was a Japanese Buddhist priest, credited with founding the Rinzai school, the Japanese line of the Linji school of Zen Buddhism. In 1191, he introduced this Zen approach to Japan, following his trip to China from 1187 to 1191, during which he was initiated into the Linji school by the master Hsü an. It is also said that he popularized green tea in Japan, following this same trip. He was also the founding abbot of Japan's first Zen temple Shōfuku-ji and Kennin-ji. He is often known simply as Eisai/Yōsai Zenji (栄西禅師), literally "Zen master Eisai". Biography Born in Bitchū Province (modern-day Okayama, Okayama), Eisai was ordained as a monk in the Tendai sect. Dissatisfied with the state of Buddhism at the time, in 1168 he set off on his first trip to Mount Tiantai in China, the origin of the sect, where he learned of the primacy of the Chan (later known in Japan as Zen) school in Chinese Buddhism of the time. He spent only six months in China on this first trip, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism. Examples of investigations ''in vivo'' include: the pathogenesis of disease by comparing the effects of bacterial infection with the effects of purified bacterial toxins; the development of non-antibiotics, antiviral drugs, and new drugs generally; and new surgical procedures. Consequently, animal testing and clinical trials are major elements of ''in vivo'' research. ''In vivo'' testing is often employed over ''in vitro'' because it is better suited for observing the overall effects of an experiment on a living subject. In drug discovery, for example, verification of efficacy ''in vivo'' is crucial, because ''in vitro'' assays can sometimes yield misleading results with drug c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavanol
Flavan-3-ols (sometimes referred to as flavanols) are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2''H''-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of compounds, such as catechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins, thearubigins. They play a part in plant defense and are present in the majority of plants. Chemical structure The single-molecule (monomer) catechin, or isomer epicatechin (see diagram), adds four hydroxyls to flavan-3-ol, making building blocks for concatenated polymers (proanthocyanidins) and higher order polymers (anthocyanidins). Flavan-3-ols possess two chiral carbons, meaning four diastereoisomers occur for each of them. They are distinguished from the yellow, ketone-containing flavonoids such as quercitin and rutin, which are called flavonols. Early use of the term bioflavonoid was imprecisely applied t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicatechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from '' catechu'', which is the tannic juice or boiled extract of ''Mimosa catechu'' ('' Acacia catechu'' L.f.). Chemistry Catechin possesses two benzene rings (called the A and B rings) and a dihydropyran heterocycle (the C ring) with a hydroxyl group on carbon 3. The A ring is similar to a resorcinol moiety while the B ring is similar to a catechol moiety. There are two chiral centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in ''trans'' configuration and are called ''catechin'' and the other two are in ''cis'' configuration and are called ''epicatechin''. The most common catechin isomer is (+)-catechin. The other stereoisomer is (−)-catechin or ''ent''-catechin. The most common epicatechin isomer is (− ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicatechin Gallate
Epicatechin gallate (ECG, (−)-epicatechin-3-gallate) is a flavan-3-ol, a type of flavonoid, primarily found in green tea (''Camellia sinensis''), with smaller amounts in cocoa, grapes, and other plants. It is also reported in buckwheat and in grape. As a polyphenolic catechin, ECG is formed by the esterification of epicatechin with gallic acid, contributing to antioxidant, antimicrobial, and potential anticancer properties. ECG is studied for its ability to reverse methicillin resistance in ''Staphylococcus aureus'' and inhibit inflammatory pathways, but its clinical use is limited by poor bioavailability and thermal instability in boiling water. Recent research highlights its potential in modulating SARS-CoV-2-related inflammation and bacterial virulence factors. Epicatechin, as well as many other flavonoids, has been found to act as a nonselective antagonist of the opioid receptors, albeit with somewhat low affinity. Chemical structure and properties ECG is a flavonoid with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigallocatechin Gallate
Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin. EGCG – the most abundant catechin in tea – is a polyphenol under basic research for its potential to affect human health and disease. EGCG is used in many dietary supplements. Food sources Tea It is found in high content in the dried leaves of green tea (7380 mg per 100 g), white tea (4245 mg per 100 g), and in smaller quantities, black tea (936 mg per 100 g). During black tea production, the catechins are mostly converted to theaflavins and thearubigins via polyphenol oxidases. Other Trace amounts are found in apple skin, plums, onions, hazelnuts, pecans, and carob powder (at 109 mg per 100 g). Bioavailability When taken orally, EGCG has poor absorption even at daily intake equivalent to 8 to 16 cups of green tea, an amount causing adverse effects such as nausea or heartbur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenol
Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning (leather), tanning garments. Etymology The name derives from the Ancient Greek word (, meaning "many, much") and the word ‘phenol’ which refers to a chemical structure formed by attachment of an aromatic benzenoid (phenyl) ring to a hydroxyl (-OH) group (hence the ''-ol'' suffix). The term "polyphenol" has been in use at least since 1894. Definition Polyphenols are natural products with "one or several hydroxyl groups on aromatic rings", including four principal classes: phenolic acids, flavonoids, stilbenes, and lignans. Flavonoids can be grouped as flavones, flavonols, flavanols, flavanones, isoflavones, proanthocyanidins, and anthocyanins. Particularly abundant flavanoids in foods are catechin (tea, frui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astringent
An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin '' adstringere'', which means "to bind fast". Astringency, the dry, puckering or numbing mouthfeel caused by the tannins in unripe fruits, lets the fruit mature by deterring eating. Tannins, being a kind of polyphenol, bind salivary proteins and make them precipitate and aggregate, producing a rough, "sandpapery", or dry sensation in the mouth. Smoking tobacco is also reported to have an astringent effect. In a scientific study, astringency was still detectable by subjects who had local anesthesia applied to their taste nerves, but not when both these and the trigeminal nerves were disabled. Uses In medicine, astringents cause constriction or contraction of mucous membranes and exposed tissues and are often used internally to reduce discharge of blood serum and mucous secretions. This can happen with a sore throat, hemorrhages, diarrhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tannins In Tea
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel of tea. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids. Polyphenols found in green tea include, but are not limited to, epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin; flavanols such as kaempferol, quercetin, and myricitin are also found in green tea. Catechins Catechins include epigallocatechin-3-gallate (EGCG), epicatechin (EC), epicatechin-3-gallate (ECg), epigallocatechin (EGC), catechin, and gallocatechin (GC). The content of EGCG is higher in green tea. Catechins constitute about 25% of the dry mass of a fresh tea leaf, although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from ''Camellia sinensis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steeping
Steeping is the soaking of an organic solid, such as leaves, in a liquid (usually water) to extract flavours or to soften it. The specific process of teas being prepared for drinking by leaving the leaves in heated water to release the flavour and nutrients is known as steeping. Herbal teas may be prepared by decoction, infusion, or maceration. Some solids are soaked to remove an ingredient, such as salt, where the solute is not the desired product. Corn One example is the steeping of corn (or maize), part of the milling process. As described by the US Corn Refiners Association, harvested kernels of corn are cleaned and then steeped in water at a temperature of for 30 to 40 hours. In the process their moisture content rises from 15% to 45% and their volume more than doubles. The gluten bonds in the corn are weakened and starch is released. The corn is then ground to break free the germ and other components, and the water used (steepwater), which has absorbed various n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
