Optimization of Convective Hot Air Drying of Plantain Slices Using Response Surface Methodology

Abstract

In this study, the combined effect of volumetric air flow rate, relative humidity, temperature and time were evaluated in the drying of plantain. Response surface methodology (RSM), using central composite design (CCD), as a tool, was used to develop, validate and optimize statistical models in order to establish the individual and interactive impact of the drying parameters on the corresponding responses (moisture, carbohydrate and protein content and total plate count). Carbohydrate and protein contents were maximised while the moisture content and the total plate count were minimised.

By applying the desirability function (obtained as 0.970), the optimum values of 0.1 m³/s, 72.12%, 72.45⁰Cand 344.58 minutes (for air flow rate, relative humidity, temperature and time respectively) were obtained – with corresponding predicted (experimental ± standard deviation) responses of carbohydrate, 81.50% (80.74% ± 0.3); protein 4.23% (4.61% ± 0.4), moisture content 0.75 (1.2 ± 0.56) and total plate count, 0.99cfu (1.4 ± 0).