Abstract
The effect of electricity on the activity of pectin methylesterase (PME) in tomato juice was studied to determine its inactivation mechanism. In this study, the PME in tomato juice was inactivated by applying high electric field alternating current (HEF-AC), raising the temperature to 85° in 0.01 s, and maintaining that temperature for 3.0 s. Such inactivation by HEF-AC was 100 times faster than that by conventional heating at a temperature range of 55°C to 80°C. Whereas the inactivation rate of extracted PME remained low following conventional heating (< 65°C), HEF-AC (> 75°C) increased the inactivation rate of extracted PME to levels similar to that of non-pulp PME. It was assumed that PME attached to the pulp was released by HEF-AC and subsequently denatured at high temperature.
