Abstract: To assess the effects of tea polyphen ols(TP)on the properties ofα-amylase extracted fromAspergillu s Oryzae.α-amylase fromAspergillus Oryzae wa s complexed with TP extracted fromgreen tea.Bernfeild method was adopted to analyze the activities of freeα-amylase and TP complexedα-amylase under various temperature s,pH values and substrate concentration s.It was found that TPwere haze -active and showed no inhibitory effect on theα-amylase.By complex and sedimentati on,the maximum recovery of theα-amylase activity reached about 71%at0.3%TP concentrations.The optimum temperatures for theα-amylase were changed from30～50℃to60～70℃,pHvaluefrom3.0～8.0to5.0～6.0andt heKmvalueoftheα-amylase complexedwithTP from0.18%to1.03%the substrate concentration of solu ble starch.It is concluded that TP re covered the activity of theα-amylase and showed no inhibitory effect by compl exation.After complexed with TP,th e optimumtemperature and pHvalue fo r theα-amylasewereincreasedand narrowe d TheKmvaluewas changedhigherforsolublestarchsubstrate,indicatin gthe decreased affinity of theα-amylase with the substrate.

Key words: Tea polyphenols, α-amylase , Complex