Extraction and clarification of apple juice with polygalacturonase obtained from apple (Malus domestica) fruits deteriorated by Aspergillus niger

摘要

Pectinase is used commercially in the clarification and extraction of fruit juice from different fruits.udGreen apples and Red apples obtained from the fruits section of a supermarket, Idiroko road, Ota were surfaceudsterilized and inoculated with Aspergillus niger. The stock culture was subcultured on Sabouraud Dextroseudagar plates and 72-hr-old culture of Aspergillus niger served as the inoculum. The fruits were incubated forudtwenty-five days at room temperature (25 °C). Control fruits were similarly treated except that sterile inoculumudwas used for the inoculation. Extracts from the inoculated fruits exhibited appreciable polygalacturonaseudactivity while those from the uninoculated fruits possessed only traces of the enzyme activity. Theudpolygalacturonase obtained after enzyme extraction was applied to freshly ripe apple fruits under controlledudexperimental conditions to investigate the role of polygalacturonase in the production of apple juice. The juiceudin the cylinder to which polygalacturonase was added was visually clearer and more than that with distilledudwater. The optimum temperature of incubation for the clarification of apple fruits with polygalacturonaseudobtained from apple fruits deteriorated by Aspergillus niger was 25 °C.ud© 2011 International Formulae Group. All rights reserved.