Nutritional and Phytochemical Composition of Bambara Groundnut (Vigna subterranea [L.] Verdc) Landraces in Kenya

Abstract

Bambara groundnut (Vigna subterranea) is a highly nutritious legume with good drought tolerance attributes and is therefore a suitable candidate for food and nutritional security especially in drought prone areas. This study was conducted to determine the nutritional and phytochemical composition of seventeen Bambara groundnut landraces that were collected from Vihiga, Kakamega, Bungoma, Busia, and Kisumu Counties in Kenya. Prior to characterization, a field experiment was set up in Ishiara Ward in Mbeere North Sub-County in Embu County for two cropping seasons to standardize and multiply the seeds. The experiment was laid out in a Randomized Complete Block Design with three replicates. The harvested seeds were analyzed for their proximate, nutritional, and phytochemical composition using standard procedures. The moisture content ranged from 3.47 to 6.24%, total ash from 3.17 to 4.69%, crude protein from 21.18 to 26.00%, and fats from 4.56 to 7.02%. Iron levels ranged from 4.07 to 5.13 mg/100 g, sodium from 25.14 to 129.66 mg/100 g, potassium from 819.34 to 1,131.80 mg/100 g, and zinc from 0.06 to 0.42 mg/100 g. The tannin levels ranged from 0.01 to 0.04 mg/g, saponins from 0.82 to 1.06 mg/100 g, alkaloids from 0.01 to 0.12 mg/100 g, and flavonoids from 4.07 to 8.45 mg/100 g. The landraces BG-125, BS-148, and BS-145 with relatively higher nutrients composition and those with high levels of phytochemicals such as BS-104 and MU-137 are recommended to plant breeders for further selection and production of certified seeds. These selections will also be promoted to the farmers for production through various extension programs.

Technical Report on the notification of dried seeds and flour thereof of Vigna subterranea (L.) Verdc. as a traditional food from a third country pursuant to Article 14 of Regulation (EU) 2015/2283

“…The concentrations of saponins in bambara groundnut dried seeds were found at around 12 g/100 g, whereas in the flour the concentration of saponins ranged from 24.2 to 29 g/100 g. Publications on saponins in bambara groundnut seeds were retrieved by EFSA and showed a large variability with concentrations ranging from 0.82 mg/100 g (Chelangat et al, 2023) up to 3.6 g/100 g (Belewu et al, 2008). The concentrations reported in these publications were significantly lower than the concentrations of saponins determined in the TF.…”

“…Alkaloids were reported at levels of 0.01-0.12 mg/100 g (Chelangat et al, 2023), 140 mg/100 g (Olaleye et al, 2013) and 0.40% (400 mg/100 g) (Mbagwu et al, 2011). EFSA notes that the methods used in these publications are based on a solvent extraction followed by weighing the precipitates in alkaline conditions.…”