Abstract:Atlantic potato was used as raw material to prepare soluble (sPPO) and membrane bound (mPPO) polyphenol oxidase. The results showed that the optimal reaction temperature of sPPO was 35 ℃, the optimal pH value was 7. The optimal reaction temperature of mPPO was 30 ℃, and the optimal pH value was 7. When pyrogallic acid and catechol were used as substrates, the Km values of sPPO were 10.04 mmol/L and 24.00 mmol/L, respectively, and the Vmax values were 443 U/mL·min and 965 U/mL·min, respectively. The Km values of mPPO were 4.98 mmol/L and 48.04 mmol/L, respectively, and the Vmax values were 299 U/mL·min and 912 U/mL·min, respectively, and the catalytic effect of pyrogallic acid was better than that of catechol. The comparison of 6 inhibitors showed that Na2SO3 had the best inhibition effect on sPPO activity and Vc had the best inhibition effect on mPPO activity. The enzymatic characteristics of sPPO and mPPO were different. The results will be provide a guiding significance for the control of enzymatic browning in the processing of potato products.
