Pulsed Electric Field: Fundamentals and Effects on the Structural and Techno-Functional Properties of Dairy and Plant Proteins

Abstract

Dairy and plant-based proteins are widely utilized in various food applications. Several techniques have been employed to improve the techno-functional properties of these proteins. Among them, pulsed electric field (PEF) technology has recently attracted considerable attention as a green technology to enhance the functional properties of food proteins. In this review, we briefly explain the fundamentals of PEF devices, their components, and pulse generation and discuss the impacts of PEF treatment on the structure of dairy and plant proteins. In addition, we cover the PEF-induced changes in the techno-functional properties of proteins (including solubility, gelling, emulsifying, and foaming properties). In this work, we also discuss the main challenges and the possible future trends of PEF applications in the food proteins industry. PEF treatments at high strengths could change the structure of proteins. The PEF treatment conditions markedly affect the treatment results with respect to proteins' structure and techno-functional properties. Moreover, increasing the electric field strength could enhance the emulsifying properties of proteins and protein-polysaccharide complexes. However, more research and academia-industry collaboration are recommended to build highly effective PEF devices with controlled processing conditions.

Keywords: functional properties; milk proteins; plant proteins; protein structure; pulse generation; pulsed electric field.

Figure 1

Diagram of a possible continuous PEF device used to treat food samples.

Figure 2

Schematic diagram of an electric circuit in a PEF device used for food processing.

Figure 3

The two main types of electrical circuits and their possible pulses shapes: (A) simple resistance–capacitance (RC) circuit and its exponentially decaying pulse shape; (B) complex electric circuit and its square pulse shape.

Figure 4

Schematic diagrams of the three main types of treatment chambers in PEF devices. (A) parallel plate chambers; (B) coaxial plate chambers; (C) colinear plate chambers.

Figure 5

Flow chart of the composition of bovine milk (Data collected from Abd El-Salam et al. [92] and Onwulata et al. [93]).

Figure 6

Mechanism of PEF effects on the structural properties of milk proteins (caseins and whey proteins); adapted with permission (License number: 5001830472118) from [4]. Copyright (2019) Elsevier.

Figure 7

Proposed mechanism of PEF effects on the emulsifying and gelling properties of proteins. This figure was created with BioRender.com, (accessed on 18 May 2022) with publication permission.