Proximate composition, functional and phytochemical properties of pre-heated aerial yam flour

Abstract

This study investigates proximate, functional properties and phytochemical composition of pre-treated aerial yam (Discorea bulbifera) flour. The aerial yam samples were divided into four equal parts and pre-treated differently (roasting, boiling, soaking), while the fourth part not treated served as control. Quality evaluation carried out includes the proximate, functional properties and phytochemical composition. The roasted-dried aerial yam flour had the highest values for crude fibre (1.82%) and carbohydrate (80.07%). The roasted-dried sample had the highest values in loose bulk density, water absorption capacity and swelling capacity (0.50 g/cm3, 4.91 g/cm3 and 1.34 g/cm3, respectively), while the soaked-dried sample has the highest values for packed bulk density and emulsion stability which are 0.5647 g/cm3 and 0.56 g/cm3, respectively. The soaked sample showed highest value for peak and trough (148.13 and 142.92 RVU, respectively), while roasted sample showed highest values for breakdown, final viscosity and set back (7.21, 186.00 and 45.08 RVU, respectively). The soaked-dried sample having the highest values for carotenoid (4.71%), and lowest value for saponin (0.35%). The boiled-dried sample had lowest values for steroid (0.47 %), while roasted-dried sample had lowest value for alkaloid (0.12 %). This study showed that some inherent positive qualities (high phytochemical content with improved functional properties) of pre-treated aerial yam, with roasted being the most improved.