BETA-GLUCOSIDASE ACTIVITY IN JUICE-PROCESSING ENZYMES BASED ON ANTHOCYANIN ANALYSIS

A screening procedure utilizing boysenberry juice as a substate, which combined HPLC and spectrophotometric analyzes, was used to measure be ta-glucosidase activity of enzyme preparations used for juice processi ng. Enzyme preparations (n = 26) were evaluated at two dosage rates. A t the mean recommended dosage, one preparation produced a decrease in total monomeric anthocyanin and cyanidin-3-glucoside, relative to a co ntrol, indicating beta-glucosidase activity. At 0.1% dosage, 4 enzymes produced a significant decrease in cyanidin-3-sophoroside and 2 enzym es caused an increase in cyanidin-3-rutinoside, indicating beta-1,2-gl ucosidase activity. Such activity in juice processing enzymes was much lower and less prevalent than found previously for beta-galactosidase . Botrytis cinerea also degraded anthocyanins in boysenberry juice.