Study On The Technology Of Eurotium Cristatum Tea Fermented By Summer And Autumn Leaves

As the dominant strain during the Fahua processing of Fuzhuan tea and playing a key role in forming the unique quality of Fuzhuan tea, Eurotium cristatum was widely noticed and studied. At the same time, the summer and autumn tea leaves are very rich in China but seriously wasted, and shall be urgently exploited by new methods. So a Eurotium cristatum tea product was made by a series of steps such as the summer and autumn tea leaves fixing, rolling, sterilization and inoculation fermentation. The fermentation technology of Eurotium cristatum tea was optimized by single-factor and orthogonal experiments. Its quality forming law was analyzed, the composition of the catechins was checked by HPLC, and the micro-organisms, heavy metals and mineral elements in Eurotium cristatum tea were analysed. The results were as follows:1.The fermentation technology of Eurotium cristatum teaIn the single-factor tests, the conditions were preferred to picking one bud with three-four leaves, rolling 20 minutes after fixed, sterilizing at 121 ℃for 15 min,and fermentation temperature 28℃. The fermentation technology of Eurotium cristatum tea was optimized by orthogonal experiments, and the best condition was A3B2C2 with 20% water loss,1.0 mL/50 g inoculum, and 8-day fermentation time.2. The dynamic law of the quality formation of Eurotium cristatum teaDuring the 14-day fermentation processing, the sensory scores of Eurotium cristatum tea increased gradually in the pre-fermentation stage, and was the highest at the 8th, and decreased gradually in the post fermentation stage. Tea polyphenols, free amino acids, soluble sugar, water extract and theaflavins of Eurotium cristatum tea generally showed a downward trend, and thearubigins increased until the 8th, and theabrowns continuously rose. At the 8th, tea polyphenols, free amino acids, soluble sugar, water extract, theaflavins, thearubigins and theabrowns of Eurotium cristatum tea were 111.08,8.40,41.17,275.78,1.17,43.07 and 12.70 g/kg, respectively.3.The catechin components of Eurotiutm cristatum teaCompared with the unfermented sample, the catechins of Eurotium cristatum tea decreased by 54.25%, and C, EC and CAF increased by 113.66%,81.09% and 36.16%, respectively, and EGC, ECG, EGCG and GCG decreased, and ECG and GCG were not detected.4.The hygienic qualities of Eurotium cristatum teaFe, Mn, Cu in Eurotium cristatum tea all meet the relevant national standards. The number of total bacterial colony and coliform are<18000 CFU/g (most were Eurotium cristatum) and<30 MPN/100 g, respectively, and the pathogenic bacterium (Salmonella, Shigella, Staphylococcus aureus, Hemolytic streptococcus) were not detected out.