Tribo-electric separation of cereal proteins: machine design, operating parameters, and particle charging on protein separation efficiency and quality.

Rising demand for plant-based proteins is driving interest in separation technologies that minimize water, chemical, and energy use while preserving ingredient functionality. Conventional wet extraction of cereal proteins typically increases environmental impact and alters the protein structure and functional properties. In contrast, electrostatic separation is a solvent-free dry fractionation approach for producing protein-enriched cereal ingredients from whole grains and processing side streams. It exploits differences in tribocharge among particles, using an electric field to selectively direct protein-rich and fiber- or starch-rich cereal fractions into separate streams. This review synthesizes current knowledge on the electrostatic separation of cereal proteins using a machine-method-materials framework.Electrostatic separation offers a water- and chemical-free route to protein enrichment and can better preserve native functionality than conventional wet processing. However, cereal protein processing remains challenging due to complex composition and process variables. The reported results often depend on optimizing airflow and electric field strength, tightly controlling moisture, and implementing hybrid or multi-pass configurations. Future progress will require improved charge control strategies, scalable separator designs, and application-driven evaluation of electrostatically enriched cereal protein ingredients in real food systems.