Pulsed Power Applications for Protein Conformational Change and the Permeabilization of Agricultural Products.

Takayuki Ohshima,Katsuyuki Takahashi,Koichi Takaki,Alexis Guionet

doi:10.3390/molecules26206288

Takayuki Ohshima, Katsuyuki Takahashi + Show 2 more

Open Access

https://doi.org/10.3390/molecules26206288

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Abstract

Pulsed electric fields (PEFs), which are generated by pulsed power technologies, are being tested for their applicability in food processing through protein conformational change and the poration of cell membranes. In this article, enzyme activity change and the permeabilization of agricultural products using pulsed power technologies are reviewed as novel, nonthermal food processes. Compact pulsed power systems have been developed with repetitive operation and moderate output power for application in food processing. Firstly, the compact pulsed power systems for the enzyme activity change and permeabilization are outlined. Exposure to electric fields affects hydrogen bonds in the secondary and tertiary structures of proteins; as a result, the protein conformation is induced to be changed. The conformational change induces an activity change in enzymes such as α-amylase and peroxidase. Secondly, the conformational change in proteins and the induced protein functional change are reviewed. The permeabilization of agricultural products is caused through the poration of cell membranes by applying PEFs produced by pulsed discharges. The permeabilization of cell membranes can be used for the extraction of nutrients and health-promoting agents such as polyphenols and vitamins. The electrical poration can also be used as a pre-treatment for food drying and blanching processes. Finally, the permeabilization of cell membranes and its applications in food processing are reviewed.

Highlights

The supply of food toward consumers is an important issue that contributes to a sustainable society
The repetitive operation compact pulsed power generators with moderate peak power suitable for use in food processing applications have been developed by many researchers for temporal and spatial control of intense electric fields and discharge plasmas
When the pulsed high voltage is applied between arbitrarily shaped electrodes, intense pulsed electric fields (PEFs) are produced between the electrodes, which causes biological effects such as electroporation of cell membranes [5] and conformational change in proteins [6]

Summary

Introduction

The supply of food toward consumers is an important issue that contributes to a sustainable society. When the pulsed high voltage is applied between arbitrarily shaped electrodes, intense pulsed electric fields (PEFs) are produced between the electrodes, which causes biological effects such as electroporation (formation of pores) of cell membranes [5] and conformational change in proteins [6]. These phenomena can be used in food proceedings such as drying, pasteurization (sterilization of bacteria), permeabilization and fermentation [1].

Pulsed Power Generators for Food Processing

Basic Circuit for Pulsed Power

MΩ 5 MΩ 1 MΩ

Pulse Compression and Forming

Protein Conformational Change by PEF Irradiation

PEF Treatment for α-Amylase Inactivation via Conformational Changes

PEF Poration Process of Cell Membranes and Its Applications

Voltage Buildup across the Cell Membrane

Critical PEF Strength for Microorganism Survivability

PEF Pasteurization

Findings

Conclusions