Scientific African (Jul 2021)
Effective moisture diffusivity of Sierrathrissaleonensis cracker: optimization, sensitivity and uncertainty analyses
Abstract
Sierrathrissaleonensis (SL) is a low valued fish in Nigeria because of its small size and availability of fleshy alternatives. Therefore, an alternative utilization of SL is crucial. In this study, SL was used to produce fish cracker (SLC). The SLC, being an intermediate product was dried to achieve moisture stability. During drying process, the influence of drying factors (oven air velocity, sample thickness and oven temperature) on the effective moisture diffusivity (EMD) of SLC was investigated using response surface methodology (RSM) in Design Expert software. The uncertainty of the result and the sensitivity analyses of the drying factors to the variations of EMD were conducted using Monte Carlo simulation in oracle crystal ball (OCB) software. Results showed that fish cracker could be successfully developed with SL. The initial moisture content (d.b) of the SLC was 149.23%. Increment in oven drying temperature and oven air velocity increased the EMD of the SLC while increment in SLC sample thickness decreased the EMD of the SLC. The model developed had an R2 value of 0.9865. Model terms were significant at 5% confidence level. The theoretical optimum drying condition given by RSM showed that SLC should be processed at oven air velocity, SLC sample thickness and oven temperature of 3 m/s, 3 mm and 60°C, respectively to give an EMD of 2.75E-08. The validated SLC optimum drying condition was 2.69E-008. The certainty of achieving the experimental data range was 99.831%. The EMD of SLC drying process had +80.4%, -16.2% and +3.4% sensitivity to oven temperature, sample thickness and air velocity, respectively. These results are useful for the economic utilization of SL and will also assist in energy economics and product standardization during drying processing of SLC.
