Nutritional Components and Digestibility Profiles of Some Potential Plant-Based Protein Sources

Abstract

Background: The dominance of soybeans as the primary plant protein source has hindered the exploration of potential sources, limiting dietary diversity and innovation. Objective/Methods: This study evaluated six plant protein sources—mung bean (MB), bambara bean (BN), jack bean (JB), sesame seed (SS), moringa seed (MS), and rice bran (RB)—compared to soybean (SB) for their chemical composition and biological qualities using standard methods. Results: Protein composition (14.98–30.29 g/100 g), fiber (2.90–8.18 g/100 g), and fat (5.19–33.30 g/100 g) varied across plants. Bulk density (0.49–0.74 g/mL), swelling capacity (0.25–0.55%), and yellowness (13.07–38.76) were comparable to SB. Electropherograms showed major protein bands at 20, 48, 75, and 100 kDa across plant proteins under non-reducing conditions. Phytate levels were highest in RB, while MS showed lower tannic acid composition (6.64 mg/100 g) compared to SB. Protein solubility (24.64–45.65%) increased with pH, while in vitro protein digestibility (74.86–87.64%) varied and was slightly below SB (91.07%); however, a similar pattern of protein digestion was observed under no reducing condition. MS and BN contained 31.17% and 42.47% of total essential amino acids with PDCAAS values of 41.42% and 58.46%, respectively. Conclusions: Overall, MS and BN exhibited superior potential as sustainable protein sources, showing properties comparable to soybean.