Physical properties, proximate composition and antioxidant activities of aerial yam (Dioscorea bulbifera) bulbils grown in Nigeria

Abstract

Aerial yam is a traditional yam species of interest among the local populations in the tropics because of their nutritional and medicinal claims. In this study, flours were produced from the two cultivars (Tob2857 and Tob3059) of Aerial Yam Bulbils (AYB) harvested at two stages of maturation. The color, functionality, proximate composition and bioactive compounds of flour were assessed. Generally, green AYB flours showed higher Hunter L* (71.86-73.68) and Whiteness index (66.31-66.92) than brown samples (Hunter L*, 71.16-72.50; Whiteness index, 62.93-64.64). Bulk density of green and brown AYB flours varied from 0.69 to 0.74 and 0.73 to 0.77 g/ml, respectively. Flours of brown AYB showed significantly higher water binding capacity (135.70-142.36%) than green samples (129.91-129.22%). Carbohydrate and protein were the main components of AYB flour. The antioxidant indices (DPPH scavenging activity, ferrous ion chelating activity, and reducing power) were higher in green AYB flours compared to brown samples and the values increased with the concentration. Therefore, the high antioxidant activity profiles of green AYB flours are desirable characteristics in food products where bioactive composition is of great importance.

Keywords

• aerial yam bulbils flour
• proximate composition
• antioxidant activity
• surface color