ACTIVITY OF PEROXIDASE DURING BLANCHING OF PEACHES, CARROTS AND POTATOES

Peroxidase (POD) activity was measured in peaches, carrots and potatoe s after blanching treatments at different constant temperatures. Two i soenzymes exist, one bound and one soluble. The bound form can be conv erted into the soluble form by a temperature-dependent conversion reac tion. Both forms are susceptible to heat denaturation. However; the co nversion precedes the denaturation of the bound form. Neat denaturatio n of the enzymes could be described using an exponential decay first o rder reaction). The temperature dependence of all reaction rates could be described by Arrhenius' law The simultaneous analysis of bound and soluble POD in peaches explained 96.4% of the observed variance. The analysis for carrots and potatoes on bound POD alone, yielded a 'perce ntage variance accounted for' of 94.5 and 70%, respectively. (C) 1998 Elsevier Science Limited. All rights reserved.