2.6. b-Glucosidase activity
The extraction of the b-D-glucoside glucohydrolase (EC 3.2.1.21) enzyme was carried out according to Carrão-Panizzi and Bordignon (2000) using 0.4 g of lyophilised sample and 5 mL of extraction solution. The enzyme activity was assessed using the method of Matsuura and Obata (1993), with minor modifications. The substrate p-NPG was diluted with a 0.1 mol L1 phosphate-citrate buffer solution at pH 6. The calibration curve was prepared by varying the concentration of p-NP from 0.04 to 0.32 mmol in a 5 mL total reaction volume. One activity unit (AU) was defined as the quantity of enzyme necessary to release 1 mmol of p-NP min1 under the experimental conditions.