Electrostatic separation technology for obtaining plant protein concentrates: A review

In recent years, animal proteins are being replaced by plant-based proteins worldwide. Artificial meat and eggs made from plant-based proteins have been widely commercialized, especially in developed countries such as the United States. However, the traditional wet separation can damage the isolated proteins as well as have a negative impact on the environment. Therefore, there is a growing research interest in developing alternative methods, such as dry separation, for high quality plant protein separation. Electrostatic separation, a dry technology based on the different triboelectric charging properties of materials, has been used for plant protein separation in recent years. This review summarizes the technical issues that need to be considered, from material preparation to equipment construction, for electrostatic separation. Moreover, the separation efficiency, energy consumption, combination with other separation methods, the functionality of the resulting protein concentrates, and prospects for electrostatic separation are also reviewed here. Factors influencing the outcomes of electrostatic separation include the pretreatment of materials, design of the electrostatic separator, and process parameters. The separation efficiency of electrostatic separation can be further improved by cyclic separation or a combination of electrostatic separation with other methods. However, although the proteins obtained by electrostatic separation maintain their native functional properties, they are affected by the presence of other components such as phenolics or starch. Thus, electrostatic separation has several limitations that need to be addressed before it can be used widely.