Enhancement of Plant Protein Extraction Using Electrostatic Separation Technology: Analysis of Material Properties, Ultrafine Flour Characteristics, Tribocharging Behavior, and the Effect on Protein Enrichment

This study used electrostatic separation to enrich dry protein concentrates obtained from six common plant-based sources: rice, wheat, mung bean, pea, fava bean, and chickpea. Initially, these agromaterials were subjected to superfine milling, tribocharging, and then electrostatic separation. Superfine milling generated small particles that facilitated the separation of the different cellular components within the agromaterials. All the ultrafine flours produced from these materials contained fine particles with a positive charge (187-774 nC/g) after tribocharging with polytetrafluoroethylene (also known as Teflon). After electrostatic separation, the fava bean protein concentrate had the highest protein purity (63.5%), whereas the pea protein concentrate had the highest separation efficiency (36.4%). The protein enrichment effect (protein purity, protein yield, and protein separation efficiency) depended on plant material properties, flour properties, and tribocharging behavior. The results of this study showed that electrostatic separation has considerable potential for enriching dry protein concentrates, which could be used to provide plant-based protein ingredients.