the CHARACTERISTICS OF LOCAL LEGUME PROTEIN CONCENTRATES EXTRACTED USING HYDROCHLORIC ACID

Protein concentrate of legumes

Abstract

Local legumes, including cowpea (Vigna unguiculata), mung bean (Phaseolus radiatus L.), and red bean (Phaseolus vulgaris L.), contain 20–30% protein, offering potential as alternatives to soy protein concentrates. This study aimed to: (1) develop a production method for legume protein concentrates using hydrochloric acid (HCl) extraction, (2) evaluate their functional properties, and (3) identify the optimal protein concentrate based on HCl concentration. A Completely Randomized Design (CRD) with three levels and three replications was employed, with Factor I being legume type (mung bean, cowpea, red bean) and Factor II being HCl concentration (3%, 5%, 7%). Results indicated that mung bean protein concentrate extracted with 3% HCl exhibited the highest protein content (21.67%), along with favorable functional properties: bulk density (0.79 g/mL), oil absorption (2.09 mL/g), water absorption (2.73 mL/g), foaming capacity (4.20%), and emulsifying capacity (23.62%). Cowpea protein concentrate required 7% HCl for optimal extraction, yielding 21.21% protein but lower functionality (emulsifying capacity: 5.38%). Red bean concentrate performed best with 3% HCl, achieving 21.18% protein and superior water absorption (3.67 mL/g).Overall, mung bean protein c oncentrate extracted with 3% HCl demonstrated the most balanced nutritional and functional characteristics, suggesting its viability as a soy protein substitute. These findings highlight the potential of local legumes in food applications, emphasizing extraction efficiency and functional performance.