STUDY OF MECHANICAL, PHYSICO-CHEMICAL AND SENSORY PROPERTIES OF PRODUCTS
Four varieties of cassava, namely: 91/02324, 97/4779, 98/2101 and NR87184
were processed into chips (30 x 2.0 x3.0 mm), ‘abacha shreds (0.80, 1.0, 1.6 mm
thick) ‘abacha’ slices (0.5 mm x 60 mm) and gari. Part of the chips was processed into ‘abacha’ slices and gari to compare the products with those made from fresh roots. The mechanical properties of the products, the hydration kinetics of the chips and the ‘abacha’ shreds as well as the chemical, functional, rheological and sensory properties of the products were studied. The results show that gari from chips and fresh cassava roots were comparable in quality in terms of chemical and rheological properties although gari from dried chips was rated low in sensory attributes. The pasting properties of gari from fresh cassava roots were significantly (ppeak viscosity of gari made from 91/02324 was the highest recorded, while the final viscosity and the trough viscosity of the product made from 98/2101 were the highest.
Cassava variety 97/4779 produced gari with the highest gel consistency when reconstituted at gari: water ratio of 1:4 (w/v) when the water was heated to 100 0C, while at water temperature of 80 0C it produced dough with significantly (pwater. Cassava variety NR87184 produced the least gel strength (soft dough) at
a water temperature of 100 0C. Generally, gari dough was found to undergo a
thinning effect with increase in water temperature and volume. The rate of
moisture uptake and the time in while the chips attained equilibrium moisture
content varied with soaking temperature and cassava variety. High coefficients of
determination (r2 =0.9656-1.000) obtained correlating the experimental and
predicted moisture uptake values for chips show that the Peleg’s equation can be
used to model water uptake of cassava chips from all four varieties. The position
(vertical/horizontal orientation) of the chips as well as the cassava varieties from
which they were made affected the mechanical properties of the chips significantly (pmechanical properties at the yield point differed significantly (ppeak value. Production of ‘abacha’ slices using dried cassava chips significantly (pproduced the most acceptable product in terms of chemical and sensory properties.
When 97/4779 was studied more concertedly for ‘abacha’ slice production,
boiling, peeling and slicing produced the most acceptable ‘abacha’ slices. Boiling
97/4779 for 30 minutes and soaking for 16 hours produced ‘abacha with the
highest protein (1.337%), while boiling for 30 minutes and soaking for 20 minutes
produced ‘abacha’ with the highest fibre content of 1.49%. The least value of
HCN (4.596mg/kg) was obtained when boiling time and soaking time were 75
minutes and 8 hours, respectively. Boiling affected the carbohydrate, ash,
protein, fat and fibre contents of ‘abacha’ slices, while soaking time significantly
(p97/4779. The pasting properties of flour made from ‘abacha’ slices processed
from fresh and dried chips of 91/02324 were higher than those made from other
varieties. Its high peak viscosity of 399.54 RVU indicates its suitability for
products that require high gel strength and high elasticity.
