Discipline: Chemistry & Chemical Sciences
Subcategory: STEM Research
Solmaz Tabtabaei - Howard University, Washington, DC
Co-Author(s): Jamaka Thomas, Howard University, Washington DC; David Gardner, Howard University, Washington DC
The main objective of this research is to develop a novel tribo-electrostatic separation (TES) technique for the fractionation of defatted soybean flour into functional protein-rich and fiber-rich ingredients in a water- and chemical-free environment followed by optimizing the separation operating parameters including air flow rates and electric field strength. The separation of defatted soybean flour into its constituent particles of protein and fiber depends significantly on the chargeability properties of these particles. Our results showed that protein particles in contact with polytetrafluoroethylene (PTFE) tribo-charger device have significantly higher chargeability properties compared to fiber particles which is mainly due to the presence of ionizable functional groups in proteins such as amine groups, carboxyl groups and side chains. Our Bioprocess Engineering Research Laboratory at Howard University has designed a custom-built tribo-electrostatic separator unit consisting of a tribo-charging tube, separation chamber with two oppositely charged electrodes, and fluidized bed. Herein, the soybean constitute particles were first charged in the PTFE tribo-charging tube to substantially different levels before being separated in the fractionation chamber under the influence of an external electric field. The optimization of process parameters was performed at two different laminar and turbulent air flow rates as well as three different plate voltages (±1kV, ±3.5kV, and ±6.5kV). At the most optimal process conditions, the initial protein and fiber contents of soybean flour were increased from 55.3% and 15.3% to 58.4% and 19.6%, respectively, accounted for 66.5% of the total protein and 60.8% of the total fiber. Further enrichment of protein content in defatted soybean flour will be performed by optimizing the design configuration of the separator through multi-stage TES processes.
Funder Acknowledgement(s): The authors acknowledge NSF, Grant No. HBCU-UP RIA -1900894 for its support.
Faculty Advisor: None Listed,
NSF Affiliation: HBCU-UP