The effect of thermal treatment on β-glucosidase inactivation in vanilla bean (Vanilla planifolia Andrews)

The conditions for enzyme activity (pH and temperature) and kinetic parameters for the thermal inactivation of beta-glucosidase enzyme in vanilla beans have been investigated. The maximum enzyme activity was detected at pH 6.5 and 38 degrees C. The values obtained for V-max and K-m were 62.05 units and 2.07 mM, respectively. When hot water treatment (the most practical method of vanilla bean killing) was applied, beta-glucosidase treated at pH 6.0 and 60 degrees C for 3 min lost 51% of activity, while at 70 degrees C for 90 s the enzyme lost 60% of activity and at 80 degrees C for 30 s the enzyme lost 48% of its activity. When vanilla beans were cured in an oven at 60 degrees C for 36 to 48 h all beta-glucosidase activity was lost.