Abstract:In this paper,guaiacol and catechol oxidation method were used to study the effect of different blanching on the peroxidase and polyphenol oxidase activity of Brassicachinensis L. The results show that the peroxidase activity of Brassicachinensis L. respectively were37.30,39.28,34.34,24.95 after blanching for 4 min at 90 ℃,2 min at 95 ℃,3 min at 95 ℃,4 min at 95 ℃,the relative residual dynamic activity decreased to 8.11%,8.53%,7.46%,5.42%. The polyphenol oxidase relative residual activity of Brassicachinensis L. were 16.49% after blanching for2min at 95 ℃ without rapidly transferring to ice bath to cool. If we transferred to ice bath to cool,the polyphenol oxidase relative residual activity of Brassicachinensis L. were 1.24%. Therefore,when the Brassicachinensis L. was blanched for 2min at 95 ℃ and then quickly transferred to ice bath to cool,the activity of peroxidase(the relative residual activity was 8.53%) and polyphenol oxidase(rhe relative residual activity was 1.24%) had been well suppressed and the relative residual activity was less than 10%,what’s more,in this blanching conditions,the content of chlorophyll was higher(2.31 mg/g),the color(the value of-a was 22.84,the value of saturation Cwas 35.56) was better.
