MORPHOLOGICAL AND CHEMICAL CHARACTERISTICS OF DIFFERENT CASSAVA VARIETIES IN RELATION TO THE QUALITY ATTRIBUTES OF THEIR GARI (ROASTED FERMENTED CASSAVA GRITS)

Abstract

Gari is the most popular cassava product in West Africa. Therefore, the suitability of any cassava root introduced into this region for gari production is important. This study determined some selected morphological and chemical characteristics of six cassava varieties (TMS 30001, TMS 30572, TME 419, TMS 98/0505, TMS 98/0581 and Biofortified) being promoted for widespread cultivation in Kwara State, Nigeria. The yield, physical, chemical and sensory attributes of gari made from these roots were also investigated. Principal Component Analysis (PCA) was conducted to identify parameters contributing to major sensory variations in the gari samples while correlation analysis was adopted to determine relationships between cassava and gari properties. Biofortified cassava had the highest root size attributes. Moisture, starch and cyanide contents of the cassava roots were 64.01-77.38%, 31.47-61.94% and 40.52-58.86 mg/kg, respectively. TMS 30001 had highest pulp-to-peel ratio (3.96) and gari yield (20.11%). The particle size distributions, angles of repose, pH, and total titratable acidity of the gari samples differed significantly (p≤0.05).  Cyanide content of gari from TMS 98/0581 was above WHO recommended safe limit of 10 mg/kg while gari from TMS 30001 had highest sesnory ratings, except in taste. PCA revealed overall acceptability, taste and colour as the top three sensory components contributing to variation in the gari samples. Root size negatively correlated with dry matter, starch content and gari yield. It was concluded that the various cassava varieties exhibited some distinct morpholgical and chemical characteristics which influenced their potentials for gari production.