Abstract
The current industrial demand for starchy foods has been dominated by other roots
and tubers, while cocoyam, despite being rich in fiber, minerals, and vitamins has remained
under exploited. In this study, the effect of feed moisture content (FMC),
screw speed (SS) and barrel temperature (BT) on the quality characteristics of cocoyam
noodles (proximate, thermo-physical,
physicochemical, texture, color, extrudate
properties, and sensory characteristics) were investigated using central
composite design (CCD) of response surface methodology (RSM). Flour was produced
from fresh tubers of cocoyam (Xanthosoma sagittifolium) and subsequently
processed into noodles using a twin screw extruder. Results showed that the proximate
compositions, thermo-physical,
physicochemical properties, and color of the
cocoyam noodles were significantly (p < 0.05) influenced by the extrusion process
variables. The texture and extrudate properties of cocoyam noodles were equally
significantly (p < 0.05) different. The experimental data obtained and predicted values
of the response models were comparable, with statistical indices [absolute average
deviation (AAD, 0–0.23), bias factor (Bf, 1–1.08), and accuracy factor (Af, 1–1.23)]
indicating the validity of the derived models. The optimal extrusion processing conditions
for quality cocoyam noodles were FMC, SS, and BT of 47.5%, 700 rpm and
50°C, respectively, as cocoyam noodles obtained at these conditions had comparable
properties and were most preferred and accepted by the sensory panelists.