Encapsulation of ?-amylase in a starch matrix

Abstract

In this study thermostable ?-amylase was encapsulated in a pregelatinized potato starch to obtain a controlled degradation upon water uptake. Encapsulation was performed using kneading, a (thermo) mechanical process. The aim of the study was to evaluate the possibility to encapsulate a degrading enzyme for a system, which can be triggered to degrade upon water uptake instead of direct water contact. After the encapsulation process, the enzyme (?-amylase) activity in the samples was found to have 90 ± 5% of activity of the unprocessed enzyme. It was seen that there was initial degradation of the starch matrix during processing, proportional to the enzyme concentration. The encapsulated enzyme was inactive during storage under low humidity conditions (RH ? 60%) and could be reactivated upon water uptake by incubation of samples in humid atmosphere (90% RH). The reduction of the molecular weight, upon activation of the encapsulated enzyme was also proportional to the concentration of the encapsulated enzyme. © 2002 Elsevier Science Ltd. All rights reserved