ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Selection of a method for determination of activity of pectinolytic enzymes in berry fruit materials

Alina Jakób, Jolanta Bryjak, and Milan Polakovič

Department of Chemical and Biochemical Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia

E-mail: milan.polakovic@stuba.sk

Received: 29 March 2009  Revised: 17 May 2009  Accepted: 17 May 2009

Abstract: The goal of the study was to find the most accurate and sensitive method for the determination of activity of pectinolytic enzymes in complex mixtures obtained from fruit materials such as raw cloudberry and raspberry juices. Several assay methods based on enzymatic reactions using viscometric, colourimetric, spectrophotometric, or pH-titration detection of the reaction products were tested. Problems with the application of the selected methods, such as very low detection signal or very large background signal, were observed. Among the tested methods, only a modified method based on the continuous recording of the released carboxyl groups titration allowed to assay the activity of exogenous pectin methylesterase with a good linearity, sensitivity, accuracy, and minimised the interference of other fruit components.

Keywords: pectinolytic activity - pectin methylesterase - determination - berry fruit

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-009-0065-z

Chemical Papers 63 (6) 677–682 (2009)