Characterization of Pectinmethylesterase, b-Galactosidase and Ascorbate Oxidase from Sicilian Blood Oranges

摘要

Appearance (browning and texture) , flavour and nutritional changes are fundamental characteristics determining the acceptability of fresh fruit and vegetables. The understanding of the biochemical processes leading to these changes is essential in developing better approaches to minimize them and, hence, improve quality and shelf life for the consumer. The aim of this work was to characterize the enzymes involved in the undesired softening and nutritional loss (ascorbic acid) in blood orange fruit (Citrus sinensis, cv. Moro and Sanguinello) , a typical Sicilian crop. Pectinmethylesterase (PME) , b-galactosidase (bGAL) and ascorbate oxidase (AAO) from orange pulp were extracted, partially purified and characterized kinetically (Vmax and Km)and technologically for optimal pH and temperature.