Inactivation of pectin Methylesterase and Lactobacillus Plantarum by ohmic heating in pomelo juice

Abstract

AbstractThe use of ohmic heating (OH) to inactivate damaging elements in pomelo juice was evaluated. The work investigated the effect of frequencies (50–20 000 Hz) on pectin methylesterase (PME) and Lactobacillus plantarum (L. plantarum) in pomelo juice at 30 V cm−1 of electric field strength. The results show that frequency does not affect PME inactivation (P > 0.05) but affects bacterial reduction and has the most efficiency at 60 Hz, followed by 50 Hz, and in the frequency range at or higher than 500 Hz (P < 0.05). Additionally, the inactivation kinetics of PME and L. plantarum and the impact of nonthermal factors were given. The nonthermal element has contributed to the inactivation enhancement of L. plantarum and PME to reduce the necessary treatment temperature and time. The major spoilage bacteria and enzyme destruction in pomelo juice occurred faster under OH than under conventional heating (CH) suggesting that OH can be effectively used to pasteurise pomelo juice.