Physicochemical and functional properties of fiber-rich hulls from different pulses: A comparative study

Authors: HONG, SHAN - Kansas State University; ROUGEAU, DIANE - Volunteer; LI, YILIN - Virginia Tech; PATEL, NIRALI - Former ARS Employee; RAJPUROHI, BIPIN - Kansas State University; Haff, Ronald; Zhang, Yuzhu; LI, YONGHUI - Kansas State University; Xu, Yixiang

Submitted to: ACS Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2025
Publication Date: 11/21/2025
Citation: Hong, S., Rougeau, D.N., Li, Y., Patel, N., Rajpurohi, B., Haff, R.P., Zhang, Y., Li, Y., Xu, Y. 2025. Physicochemical and functional properties of fiber-rich hulls from different pulses: A comparative study. ACS Food Science and Technology. Article 5c00776. https://doi.org/10.1021/acsfoodscitech.5c00776.
DOI: https://doi.org/10.1021/acsfoodscitech.5c00776

Interpretive Summary: Pulse hulls, the primary by-product of pulse processing, traditionally have been used as low-value animal feed but are increasingly recognized as potential sources of dietary fiber. Upcycling them for high-value applications is essential to improve the economic and sustainability of the pulse industry. The purpose of this study was to conduct a comprehensive analysis of the chemical compositions, physicochemical attributes, and functional properties of the hulls derived from the six most prominent pulses (i.e., chickpea, red lentil, yellow pea, cowpea, black bean, and faba bean). The compositional and structural differences among these hulls translated into diverse functional properties, which offer valuable insights into their suitability for various end uses. The findings highlight the potential efficacy of pulse hulls as antioxidant and fiber-rich ingredients for functional food applications.

Technical Abstract: This study compares proximate composition, physicochemical and functional properties, and antioxidant activities of pulse hulls from six most prominent pulse types: chickpea, red lentil, yellow pea, cowpea, black bean, and faba bean. All studied samples were found to be rich in dietary fiber (49.1 – 65.4%), while low in protein (3.9 – 13.9%), ash (2.23 – 5.03%), and fat (0 – 0.71%). Scanning electron microscopy revealed distinct surface morphologies across samples. Variations in compositional profiles and microstructures resulted in versatile functional properties. Chickpea hull displayed the highest water/oil holding (5.91 g/g and 1.48 g/g), and water swelling (4.17 mL/g) capacities. Red lentil hull exhibited the highest glucose adsorption (308.0 mg/g) and exceptional cholesterol binding (135.2 mg/g) capacities, while cowpea hull exerted the greatest sodium cholate binding capacity (29.9 mg/g). Colored hulls (red lentil, faba bean, black bean, cowpea) demonstrated significantly higher total phenolic content (8.5 – 35.7 mg gallic acid equivalent (GAE)/g) with the highest value for red lentil, as opposed to the light-colored chickpea and yellow pea hulls (' 1 mg GAE/g). Antioxidant activities, as assessed by DPPH•, NO•, and ORAC assays, positively correlated with phenolic content (r ' 0.992, 0.906, and 0.936, respectively, p <0.05).The findings provide fundamental insights into the effective valorization of pulse hulls as high-value-added and fiber-rich ingredients for functional food applications.