Comparative Analysis of the Proximate Composition, Amylose Content, Functional and Pasting Properties of Three Underutilized Legumes

Abiodun Folasade AKINSOLA

amylose,flour,legume, pasting properties, proximate composition,

This study was conducted in order to compare the proximate composition, amylose content, functional properties, swelling power and pasting properties of whole pigeon pea, lima bean and African yam bean flours using standard analytical methods. The proximate composition of the legume flours showed that the amount of moisture ranged from 6.43-7.24%; crude protein, 23.6-28.5%; crude fat, 1.42-2.48%; ash, 3.35-3.74%; crude fibre, 3.48-4.93%; and carbohydrate, 55.6-59.9%.  The amylose contents of the legume samples were significantly different. African yam bean flour had the highest amylose content with 16.9±0.3%, while pigeon pea flour had the lowest value (14.8±0.0 %).Results showed that the mineral composition of the three legume flours differed significantly. Pigeon pea flour had the highest amount of most of the minerals analyzed (Na, K, Mg, Ca, P, Fe, Zn, Mn and Cu) (P<0.05) followed by lima bean flour. Except for sodium and manganese, African yam bean flour had the lowest mineral values of all the elements analyzed.Regarding functional properties, lima bean flour had the highest water absorption capacity (240±6%), while pigeon pea flour had the least (120±0%). There was no significant difference in the emulsion capacity value of the three samples. The least gelation concentration of the legume flours ranged from 6-10 with pigeon pea flour having the lowest value. Lima bean flour had the highest swelling power at 60, 70 and 95^oC while pigeon pea flour had the lowest swelling power at each temperature studied.Results of the pasting properties revealed that lima bean flour had the highest peak and final viscosity values (139±7 and 198±4 RVU), followed by African yam bean flour (128±2 and176±4 RVU) and pigeon pea flour (99.8±3 and 114±4RVU). The pasting temperatures of the three legume flours were not significantly different. The results obtained in the study showed that these legume flours could be used as functional ingredients in food systems.

https://doi.org/10.31871/IJNTR.9.5.15