ORANGE PECTINESTERASE: PURIFICATION, PROPERTIES, AND EFFECT ON CLOUD STABILITY

Abstract

ABSTRACT Orange pectinesterase was isolated by ammonium sulfate fractionation followed by ion exchange on CM‐Sephadex column. Two pectinesterase peaks were observed, The same pH and temperature optima (pH 7.5, temp 60°C), almost equal Michaelis constants (0.029%, 0.031%) and energy of activation values (5,600 cal mol ‐1 , 5,740 cal mol ‐1 ) were obtained for the two pectinesterase fractions. Both enzyme fractions were inhibited by EDTA and polygalacturonic acid and were found to cause clarification of orange juice in a pattern similar to that obtained with natural juice. It can be assumed that the two pectinesterase chromatographic entities have similar catalytic properties.