Experimental studies of a hybrid peeling process for cassava roots.

Peeling is an essential unit operation before further processing of cassava. This study presents functional and proximate composition of gari and HQCF as affected by peeling methods and cassava cultivars. An abrasive peeling machine with dual function of mechanical and mild chemical peeling of cassava roots by recycling of fruit water was developed. The peeling machine utilizes abrasive peeling surface inscribed with indented 0.12 cm stainless steel of 77 cm height with 245 cm diameter, a stainless steel based cavity, fruit water recovery tank, water pump and the transmission system. The fruit water was used to soak the cassava tubers before peeling with the machine for 60 minutes. Peeling of cassava by hands were used as control for this study. Improved cassava varieties: TMS 30572 and TME 419 were used. High quality cassava flour (HQCF) and gari produced from the varieties with three different peeling methods: manual, mechanical and mechanical/chemical (hybrid), were analyzed. The moisture content (MC), crude fat (CFT), crude protein (CP), ash, carbohydrate, cyanide content (CC), pH, packed bulk density (PBD), oil absorption capacity (OAC), least gelation concentration (LGC), water absorption capacity (WAC), swelling power (SP) and solubility from proximate composition and functional properties of HQCF for TME 419 were 11.00%, 0.00%, 0.35%, 0.0%, 0.20%, 88.45%, 1.98 mg kg-1, 5.50, 0.64 g ml-1, 144%, 6.67%, 147.5%, 887.05%, and 6.28%, respectively while values for TMS 30572 were 10.8%, 0.0%, 0.24%, 0.0%, 0.10%, 88.86%, 2.04 mg kg-1, 5.96, 0.61 g mL -1, 125%, 4.00%, 152.5%, 854.38%, and 6.00%. The MC, CP, CFT, CF, ash, carbohydrate, CC, pH, PBD, WAC, SP and solubility from proximate composition and functional properties of the gari produced for TME 419 were 6.51%, 1.42%, 0.31%, 2.21%, 0.80%, 88.75%, 2.92 mg kg-1, 4.82, 0.56 g ml-1, 320.21%, 830.55% and 6.25%, respectively, while that of TMS 30572 were 7.00%, 1.52%, 0.42%, 2.33%, 0.71%, 88.02%, 3.14 mg kg-1, 4.35, 0.675 g mL -1, 430.39%, 860.38% and 6.50% across the peeling methods. HQCF and gari had proximate and functional properties that compared favourably with those of manual peeling of cassava for the products. The functional properties were well improved by the hybrid and mechanical peeling methods. [ABSTRACT FROM AUTHOR]