Two-stage water blanching of asparagus

Abstract

Asparagus, Argentuille variety, was water blanched for different times at 76, 88 and 100°C, in order to study thermal inactivation of peroxidase in asparagus tips and stalks. A two-stage blanching method, in which the asparagus stalk was initially immersed in the water bath for an interval after which the tip was immersed, was also evaluated. At 100°C and at a blanching time between 50 and 60% of that used for the stalk, the peroxidase activity of the asparagus tip was similar to that of the asparagus stalk. A procedure was developed to predict residual peroxidase activity in asparagus stalks and tips during two-stage water blanching at 100°C. Predicted values agreed well with experimental results.