Evaluation of nutritional, antinutritional, functional properties and cooking time of improved cowpea (Vigna unguiculata (L.) Walp.) varieties grown in Ethiopia

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is an important legume and an alternative source of protein which can be used as a substitute for animal protein that is limited in supply in Ethiopia. This study was initiated to evaluate the nutritional, antinutritional, functional properties and cooking time of two improved cowpea (Vigna unguiculata (L.) Walp.) varieties (Bole and Kanketi) grown in Ethiopia. The crude protein (28.80%), total ash (5.04%) and total energy (336.89 Kcal/100g) contents were higher for Bole variety than Kanketi variety (25.32%, 4.71% and 329.72 Kcal/100g), respectively. Kanketi variety had greater moisture content (8.91%), crude fiber (6.60%), crude fat (2.12%) and digestible carbohydrate (52.34%) than Bole variety (8.45%, 4.71%, 1.91% and 51.12%), respectively. The mineral content of the Bole variety revealed significantly higher values of Ca (43.36 mg/100g), Zn (6.17 mg/100g) and Fe (15.65 mg/100g) than Kanketi variety (41.91 mg/100g, 4.99 mg/100g and 13.32 mg/100g), respectively. Tannin and phytic acid content were found in the range of 28.43 to 31.23 mg/100g and 80.37 to 127.99 mg/100g, respectively, for Bole and Kanketi varieties. Both varieties had no significance (p < 0.05) difference on swelling power. Water solubility (20.19%) and oil absorption capacity (2.24 g/g) were significantly (p < 0.05) higher for Bole variety than Kanketi variety (17.56% and 2.06 g/g). Bulk density and water absorption capacity were found in the range of 0.75 to 0.79 g/ml and 2.39 to 2.54 g/g, respectively, for Bole and Kanketi varieties. The cooking time was significantly (p < 0.05) higher for Kanketi (27.42 min) than Bole variety (17.59 min). The results showed that Bole variety had good nutritional potential, low antinutritional factor, better functional properties and short cooking time than Kanketi variety. Hence, it can be used as a raw material in the food processing industries in the production of quality weaning and supplementary food products.