Underutilised legumes: potential sources for low-cost protein

Area of Science:

• Agricultural Science
• Food Science
• Nutritional Biochemistry

Background:

• Legumes are a vital source of plant-based protein.
• Assessing the nutritional profile of diverse legume seeds is crucial for food security.
• Understanding variations in seed composition can identify novel food and feed sources.

Purpose of the Study:

• To analyze the nutritional composition of seeds from 104 leguminous species across 17 genera.
• To identify legume species with protein, oil, and essential amino acid profiles comparable or superior to soybean.
• To evaluate the presence of trypsin inhibitor activity (TIA) and fatty acid profiles in promising legume seeds.

Main Methods:

• Proximate analysis of seeds for protein, fiber, carbohydrate, ash, and oil content.
• Detailed investigation of oil-bearing seeds for fatty acid profiles and amino acid composition.
• Quantification of trypsin inhibitor activity (TIA) in selected legume seeds.

Main Results:

• Protein content varied from 11.0% to 51.6%, with several species like Bauhinia retusa (51.6%) and B. variegata (46.5%) showing higher protein than soybean (42.8%).
• Oil content ranged from 1.3% to 19.8%, with species such as Psophocarpus tetragonolobus (19.8%) and Parkia biglandulosa (18.9%) exhibiting oil levels comparable to soybean (18-22%).
• Essential amino acid profiles were reasonably balanced, and some seeds contained high amounts of unsaturated fatty acids; TIA ranged from 48.7-87.5 mg/g.

Conclusions:

• Numerous leguminous species possess significant nutritional value, offering high protein and oil content.
• Several underutilized legumes demonstrate potential as sustainable alternatives to soybean in food and feed applications.
• Further research into processing methods to mitigate TIA is warranted for optimal utilization of these legume resources.