Thermal and high-pressure inactivation kinetics of carrot pectinmethylesterase: from model system to real foods

Pectinmethylesterase (PME) was extracted from carrots (Daucus carrota) and subsequently purified by affinity chromatography on a CNBr-Sheparose-PME inhibitor (PMEI) column. Detailed kinetic studies on the inactivation of purified carrot PME by thermal and high-pressure processing were performed. Next to the model systems, the thermal and high-pressure inactivation of PME in real products (carrot juice and carrot pieces) was investigated. The inactivation was performed under isothermal and isothermal–isobaric conditions. Under all conditions investigated, a first-order kinetic model could describe the inactivation data. It was found that carrot PME is much more thermostable and pressure-stable in carrot pieces than in carrot juice or purified form.