High pressure effects on myrosinase activity and glucosinolate preservation in seedlings of Brussels sprouts

Combinations of pressure, temperature and time (100-600 MPa, 30-60 degrees C, 3-10 min) influence enzyme activity of the myrosinase-glucosinolate system. Seedlings of Brussels sprouts were used as a model, which constitutes a well-defined and homogenous sample matrix with simple cell structures. A response surface methodology approach was used to determine the combined effect of pressure level, temperature and time on glucosinolate concentration and myrosinase activity in Brussels sprouts seedlings. The effects on residual myrosinase activity and intact glucosinolate concentration differed according to combinations of pressure, time and temperature. The results showed that maximum inactivation of myrosinase and preservation of glucosinolate (85% of the untreated level) was obtained after HP treatment at 600 MPa, 60 degrees C, 10 min. The highest preservation of myrosinase activity compared to untreated seedlings was after HP at 100 MPa, 30 degrees C, 3 min and 10 min with low degree of cell permeabilization.