Continuous ohmic heating system for the pasteurization of fermented red pepper paste

Abstract

Ohmic heating (OH) is a processing in which heat is generated inside foods by the passage of electric current. This study aimed to determine the optimal conditions for pasteurizing the Gochujang Korean-style fermented food containing hot pepper paste using a continuous OH system. The effective conditions for OH involved three pairs of electrodes connected diagonally and excitation over the voltage range of 50–100 V. The selected conditions provided heating above 100 °C without scale buildup. A microbial inactivation with a 2 log reduction was achieved by the OH, with the processing time being shorter than for conventional heating (CH). OH was available for 57 cycles during 1 cycle of CH, and it could process 104.4 kilotonnes of product. The consistency index related to thickening properties was markedly higher for OH than for CH. This study has confirmed that continuous OH is suitable for the heat-based sterilization of highly viscous foods. Industrial relevance Ohmic heating (OH) is a food processing technique in which heat is generated inside food products by the passage of alternating electric current. This study aimed to determine the optimal conditions for pasteurizing the Gochujang Korean-style fermented food containing hot pepper paste using a self-designed continuous OH system. The effective conditions for OH involved three pairs of electrodes connected diagonally and excitation over the voltage range of 50–100 V. The selected conditions provided heating above 100 °C without scale buildup. The rapid and uniform OH produced a microbial inactivation effect of a 2 log reduction despite the shorter processing time than for batch-type conventional heating (CH). OH was available for 57 cycles during 1 cycle of CH, and it could process 104.4 kilotonnes of food products. And the continuous OH is suitable for the heat-based sterilization of highly viscous foods and could result in better energy efficiency and be suitable for implementation in industrial applications. © 2017