| Abstract: | Pectinesterase from apple was separated into two fractions by chromatography on Sephadex G-75. The major pectinesterase was purified by cation-exchange chromatography on CM-Sephadex C-50. It had a molecular mass of 36 kDa, and isoelectric point of about 9, similar to one of the major pectin-esterases of lemon. The enzyme required the presence of cations for optimum activity and was completely inactive at temperatures above 75°C. Although the major pectinesterase had no effect on the cloud stability of apple juice, a fraction containing a minor pectinesterase caused cloud clarification. |
