Optimization of the Tunnel Drying Process of Cassava Chips Using Response Surface Methodology

Abstract

Background and Objectives: Nigeria is the one of the largest producers of cassava chips in the world but the chips that are produced is often of low quality because of inadequate and ineffective methods drying techniques used to produce those chips. This study examined the critical factors in the optimization of the drying process of cassava chips in order to address the problem of low quality often occur in locally produced chips when compared to foreign ones. Materials and Methods: In this study, response surface methodology was used to investigate the effect of 3 drying factors [temperature (53-86EC), air velocity (0.98-5.0 m secG1) and loading density (3.32-6.68 kg mG2)] on the responses using central composite design (CCD). Process responses of the CCD recorded were moisture content, bulk density, water absorption capacity, swelling capacity, residual cyanide and color. Results: The optimum values of moisture content, bulk density, water absorption capacity, swelling capacity, residual cyanide and color were 10.22% (wet basis), 0.39 g cmG3, 4.320 cm3 gG1 sample, 2.26 g gG1 water sample, 3.78 mg kgG1 HCN sample and 0.25, respectively. Conclusion: Lower temperatures of drying minimally reduced the level of cyanide content and gave finest color to the chips. Contrariwise, higher drying temperatures reduced moisture content and bulk density of the chips. Key words: Tunnel drying, cassava chips, optimization, response surface methodology, moisture content and bulk density