Determination of physicochemical properties of faba bean, sunflower meal, and pumpkin seed plant protein concentrates

This study presents a comparative evaluation of the physicochemical and functional properties of protein concentrates derived from faba bean, sunflower meal, and pumpkin seed. The analytical results showed that the faba bean protein concentrate exhibited the highest total protein content (90.02%, dry basis) and the lowest ash content (3.43%, dry basis), indicating a purer composition and greater protein enrichment compared to the other sources. Regarding physical properties, the faba bean concentrate demonstrated the best flowability and lowest cohesiveness, with the lowest Hausner Ratio (1.19) and Carr Index (16.01), suggesting its suitability for efficient handling and processing in powder-based food applications. Protein solubility analyses showed that all concentrates had the lowest solubility at pH 4, near their isoelectric points, but solubility improved significantly at higher pH values up to 10. The faba bean protein maintained over 80% solubility at pH 7 and nearly 90% at pH 10, highlighting its favorable dispersion and structural stability in both neutral and alkaline environments. Similarly, foaming capacity increased with pH values for all samples, with faba bean protein again outperforming the others, achieving 59.93% foaming capacity at pH 10, which is an essential characteristic for aerated food systems. Colorimetric analysis revealed that pumpkin seed protein concentrate had the darkest appearance ( L* : 61.20; a* : −7.32), due to retained pigments, whereas the faba bean and sunflower protein concentrates displayed brighter and more neutral tones. Collectively, the findings highlight the superior compositional and functional profile of the faba bean protein concentrate, making it a promising ingredient for use in plant-based beverages, baked goods, and emulsified food products. This study demonstrates that the type of plant and the processing method of the protein are crucial factors in determining the effectiveness of plant-based protein concentrates in food products.