Effect of different starter rate on content of bioactive ingredient in fermented mulberry-leaf tea

Objective:The content change of DNJ, flavonoid, polysaccharid and polyphenol in fermented mulberry-leaf tea with different strains rate was studied.Methods:DNJ was determined by HPLC, flavonoid, polysaccharid and polyphenol were determined by spectrophotometric method.Results:Compared with mulberry-leaf tea by natural fermented, DNJ content in all kinds of fermented Mulberry-leaf tea fermented by AsPergillus niger + Rhizopus japonicus Vuillemin + Trichoderma viride was increased, DNJ in Mulberry-leaf tea fermented by AsPergillus niger∶Rhizopus japonicus Vuillemin∶Trichoderma viride=2∶1∶2 increased the highest 8.94%, the contents of flavonoids, polysaccharides, tea polyphenol content were decreased in most of the fermentated mulberry- leaf tea sample, which fermented by different AsPergillus niger+Rhizopus japonicus Vuillemin+Trichoderma viride rate.The contents of flavonoids in mulberry-leaf tea fermented by AsPergillus niger∶Rhizopus japonicus Vuillemin∶ Trichoderma viride =1 ∶1 ∶1 had decreased highestly 15.39%.Contents of polysaccharides had decreased 13.30%, when the ratio was 2∶1∶2.The contents of tea polyphenol had decreased highestly 23.90%, when the ratio was 1∶2∶2.The contents of DNJ was increased 6.43%, flavonoids increased 1.16%, polysaccharides decreased 6.78% and tea polyphenol increased 1.68% in Mulberry-leaf tea fermented by AsPergillus niger ∶Rhizopus japonicus Vuillemin ∶Trichoderma viride =1 ∶2 ∶1.Conclusion:Mulberry-leaf tea had a better integrated quality fermented by AsPergillus niger∶Rhizopus japonicus Vuillemin∶Trichoderma viride=1∶2∶1, DNJ in fermented mulberry- leaf tea could be improved by AsPergillus niger∶Rhizopus japonicus Vuillemin∶Trichoderma viride=2∶1∶2.