Rapid Fermentation Of Pu'erh Tea And Its Products

Pu'erh tea,as a kind of dark tea,has been a long-time customer favorite due to its antioxidant activity,its effects on lipid lowering and weight losing,and its ability to improve the heart and blood vessel health.There are two types of Pu'erh tea,raw tea and ripe tea.The raw Pu'erh is aged naturally,which often takes more than one decade to mature before it is ready for consumption.The ripe Pu'erh,on the other hand,is processed using wet piling fermentation to accelerate the maturation.The traditional wet piling adopts natural fermentation utilizing the metabolism of microbes that grow on the harvested tealeaves,and therefore often suffers from the contamination of saprophytic bacteria,harmful bacteria,and mites.Here,we isolated three microbes that exhibited growth advantage,including the Aspergillus niger SM-H,the yeast SM-J,and the lactic acid bacteria SM-R,from the fermenting piles in Yunnan Simao,and prepared a mixture of these microbes at a 50:15:1 ratio.The rough tea was fermented with this mixture of microbes in solid-sate at 30?.The enzyme activities of protease,cellulase,and diastase reached the maximum on the fourth day of fermentation.The maximum oxidation rate of tea polyphenols was reached the highest on day 4 to day 6.From day 6 to day 12,the maximum production rate of tea pigments was reached.The overall fermentation period was shortened to 30 days,compared with the original period of 40-45 days.This new fermentation process described in this paper can be widely employed to produce Pu'erh tea in different forms,such as the loose Pu'erh tea.the pressed Pu'erh tea,and the instant Pu'erh tea.A characteristic feature of Pu'erh tea fermentation is the oxidation of tea polyphenols,which yields tea pigments.The remarkable functions of high-quality Pu'erh tea result from the massive accumulation of the tea pigments.This paper established a protocol for extracting tea pigments from fermented Pu'erh tea using single factor and orthogonal experiments.At a 1:30(g/ml)material-water ratio,a one-time extraction of tea pigments were conducted with the aid of sonication at 60 Hz for 35 min at 80?.The extracted tea pigments contained theaflavins,thearubigins,and theabrownins.Compared with the unfermented rough tea,the total amount of tea pigments increased after fermentation,and the contents of each tea pigment component also changed,with theaflavins and thearubigins converted into theabrownins.The tea pigments extracted by this approach can be used to develop Pu'erh tea functional beverage.Without changing the basis of beer fermentation process,we added Pu'erh tea juice into the wort for fermentation.After 20 min of boiling of the wort,5%of Pu'erh tea juice was added into the wort,together with the hops.After 8 days of main fermentation and 22 days of secondary fermentation,the final alcohol content was 3.3%-3.4%,and the color was 38-40.The beer featured the hops aroma,the refreshing taste,the fragrance of Pu'erh tea,and the unique color.This Pu'erh tea beer contains functional factors such as tea pigments and tea polyphenols,therefore is far more beneficial than regular beer and can be promoted as functional beer.