| Vietnam has a long history of tea, tea is now one of the world’s top ten exporters. After the history and cultural development of the Vietnamese tea has always existed and developed Vietnam puer tea is a variety of Shan sun shai qing as raw material, after special fermentation production it becomes a kind of tea, puer tea has many health benefits.In recent years, China, Hong Kong, Taiwan, Japan, south Korean consumers as warmly welcome this product.As a result Vietnam has produced a large number of it.Pu’er pile fermentation process is based on the inclusion composition of sun shai qing, the microbial enzyme secretion of extracellular enzyme, microbial respiratory metabolism of hot and humid heat and tea water of cooperation with occurred in tea polyphenols into the main body of a sery of complex chemical changes, thereby to realize puer tea unique flavor. Therefore, the essence of the tea quality is enzymatically formed with heat effect (including bio-thermal heat source which exogenous heat drying process and career microbial process heap released) involve with the combined effect of microbial, that contain ingredients to achieve series such as oxidation, polymerization, condensation, decomposition of complex chemical changes, enabling the formation of the corresponding product quality tea, so that the color green, dense taste cool, the aroma of fresh drying green Maocha into reddish brown color, taste mellow, Chen alcohol aroma tea In this process, the tea contains ingredients and content has changed dramatically.The experimental drying green Maocha varieties from Vietnam Shan Pu’er tea pile fermentation heap conducted to study the chemical process with aroma substances, and microbial variation.In addition with a the comparision with both Vietnam pu’er tea and yunnan pu-er tea, the main research conclusions are as follows:1,Vietnam tea pile fermentation which contain ingredients with dramatic changes during the process of tea polyphenols, theaflavins, tea red pigment content continue to declinea a drop of55.71,39.13,93.18%; Tea brown content increased growth53.9%; Caffeine, in the process of the water extract content pile with have changed, but the final content changed little a decline of18.74,25.64%.2,The process of the catechins composition of Vietnam’s tea pile fermentation is as follows:the changes of EGCG, ECG, EGC levels have fell sharply a drop of99.54,90.54,84.76%; C has totally fallen, a drop of38.72%. 3,During the process of the pile fermentation with absent of gallic acid, the pile has increased in the begining. then gradually decline, but the total quantity has slightly increase as well, a decline of12.96%.4,Vietnam’s tea pile infested microbial fermentation process, including yeast fermentation from early to late always occupying Numbers of advantages, aspergillus oryzae whole pile process does not appear, and the number of micro-organisms of puer tea fermentation yeast process are> aspergillus Niger> penicillium> rhizopus> Aspergillus. At the beginning of the fermentation, aspergillus Niger and yeast have increased rapidly, on the other hand the microorganisms have increased relatively slow.5, Application of solid phase microextraction combined with GC/MS analysis of aroma substances in tea. Raw materials mainly terpene alcohols aroma components, after the result of the pile fermentation, the appearance of the pile of aroma substantial reduction in alcohols, aldehydes, ketones, phenols, have slightly increased with a pile of tea with methoxy benzene and terpenes. A pile of tea methoxy benzene class is one of Mouldy important aroma components. give Chen fragrant tea.6, Vietnam main chemical component of raw pu’er tea has less ripe tea than yunnan pu’er tea raw tea, specially TB, EGC, ECG... |
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