Study On Fu-brick Tea Fermented By Eurotium Cristatum And The Toxicologically Testing

This paper dicussed the condition of the Eurotium cristatum culture in liquid medium. And the Eurotium cristatum was used to ferment the Fu-brick tea while the tea and the water was also used to ferment Fu-brick tea as a contrast.The acute toxicity and the 30 days feeding test was studied.The results suggest that the best ingredient of the liquid culture medium of the Eurotium cristatum is: NaCl 32g,NH₄NO₃ 3g,sucrose20g,MgSO₄ 0.5g,K₂HPO₄ 1g ,water1000ml.And the results showed pH5.8,180 r/min rotate speed and 30℃fermentation temperature were the optimum fermentation conditions.Different innoculum dose such as 5ml,10ml and 15ml was used in the ferment of Fu-brick tea.Results reveal an obvious difference among control group,tea group and Eurotium cristatum group.The number of spore of every gram of dry tea in the control group is only 1.93×10³².09×10³ and the tea group is 2.94⁷.28×10⁴ while there is 3.13×10⁶¹7.10×10⁷ in the Eurotium cristatum group.The result of acute toxicity testing of the Eurotium cristatum is that the maximum tolerated dose is above 7.31×10¹⁰.And the 30 days feeding test showed that there is no remarkable effect in the rat's weight, haematological index and the ratio of viscera.It reveals the Eurotium cristatum is safe to eat.The result of acute toxicity testing of the Fu-brick tea fermented by Eurotium cristatum is that the LD₅₀ is above 5001mg/kg.And the 30 days feeding test showed that there is no remarkable effect in the rat's weight,haematological index and the ratio of viscera. It reveals thar the Fu-brick tea fermented by Eurotium cristatum is safe to eat.This research confirmed that the Eurotium cristatum can grow well on the tea. Eurotium cristatum ferment Fu-brick tea is a more efficiency technology to ferment Fu-brick tea which can produce much more spore in less time.And the products of this techology and the Eurotium cristatum are attested to be safe for eating.