Comparative Analysis of Proximate Compositions, Physical Properties, and Sensory Attributes of Kersting’s Groundnut (Macrotyloma geocarpum (Harms) Maréchal & Baudet) Accessions

Abstract

Kersting’s groundnut (Macrotyloma geocarpum, Harms) is a legume crop with nutritional potential in West Africa where it is widely consumed due to its palatability. The present study investigated the physical characteristics, nutritional composition, and organoleptic properties of five Kersting’s groundnut accessions selected based on their yield performance, stability, and seed color. Physical characteristics (seed size, length, and thickness) were determined using a Vernier Caliper while a laboratory weighing scale was used to determine 100-seed weight. Protein and fat contents were analyzed using micro-Kjeldahl and Soxhlet systems, respectively. Dietary fiber content was determined using the AOAC method while carbohydrate content was determined using the method of difference. Amino acids were hydrolyzed and determined using the liquid chromatography method. Ten trained panelists participated in testing the cookability of the samples while 30 untrained panelists were involved in the acceptability test. Results showed that accessions ranged between 8.1 ± 0.1 and 9.3 ± 0.2 mm for seed length, 5.7 ± 0.4 and 6.0 ± 0.2 mm for the width, and 4.0 ± 0.0 and 4.9 ± 0.4 mm for thickness. The 100-seed weight ranged from 11.7 ± 0.8 to 16.7 ± 1.6 g. Protein, fat, and carbohydrate contents ranged from 20.5 ± 0.2 to 22.0 ± 0.2, 1.2 ± 0.0 to 2.3 ± 0.0, and 56.5 ± 0.0 to 59.4 ± 0.1 (g/100 g dw), respectively. The lowest and highest cooking times were 78 and 124 minutes, respectively. All accessions recorded good sensory acceptability (>50%) except the accession BUR 16 which was liked only by 23.3%. Overall, accession OUA had the highest protein, medium cooking time, and highest overall acceptability score (>70%), hence recommended for wide production. Future studies need to be performed on the antinutritional content of this accession and to find out the effect of cooking on the nutritional value of derived meals and starch modification.