Take 0.5 g of grapes, add 2 mL of citric acid-disodium hydrogen phosphate buffer solution (pH=5.0), grind in an ice bath, freeze and centrifuge at 4 °C and 12000 rpm for 20 min, and take the supernatant to measure the enzyme activity.
Take 0.5g grape, add 2 ml citric acid disodium hydrogen phosphate buffer solution (pH = 5.0), grind in ice bath, freeze and centrifuge at 4 ℃ and 12000 rpm for 20 min, and take the supernatant to determine the enzyme activity.
Take 0.5g grapes, add 2 mL citric acid-disodium hydrogen phosphate buffer solution (pH = 5.0), grind in ice bath, freeze and centrifuge at 4℃ and 12000 rpm for 20 min, and take the supernatant to determine the enzyme activity.