High-protein dry bean flour fraction for extrusion applications

Overview

This solution offers a practical milling and sieving approach for producing high-protein pulse flour fractions from dry edible beans, providing food manufacturers with a cost-effective alternative to air-classification. Preliminary research on pinto beans demonstrated that high-speed milling followed by sieving through an 80-mesh screen increased total protein content by approximately 24.7 percent compared to raw flour. The resulting high-protein flour fraction is designed for use in extrusion applications, including snacks, cereals, and protein-enriched food products. By simplifying the fractionation process, this method can reduce equipment costs and energy demands for ingredient producers seeking plant-based protein solutions.

Technical specifications

Process and methodology:

• Dry pinto beans are milled at 10,000 rpm using high-speed fine-grinding equipment
• Milled material is fractionated using sieve separation, specifically an 80-mesh screen
• Protein content is measured using AACCI Method 46-30, with a nitrogen-to-protein conversion factor of 6.25
• The 80-mesh flour fraction achieved 29.9 percent protein concentration compared to 23.9 percent in raw flour
• Statistical analysis confirmed the protein increase is significant

Planned functional characterization:

• Water absorption index and water solubility index
• Oil absorption index
• Foam capacity, emulsion capacity, and emulsion stability
• Hydrolysis and expected glycemic index
• Extrusion product properties including expansion index, texture, and consumer acceptability

Technology readiness level

This research is at an early-to-mid stage of development. Preliminary validation has been completed on a single bean variety using a straightforward milling and sieving protocol, with statistically significant protein enrichment confirmed. Future work will expand testing to additional dry bean varieties and characterize the functional properties of the flour fraction for extrusion applications. The research team is seeking partnership with an organization that can provide a table-top laboratory extruder to enable expanded product testing. The estimated project duration is one year, positioning this technology to advance from proof-of-concept toward application-ready validation.