Comparative Study between Current Practices on Cassava Drying by Small-Size Enterprises in Africa

Marcelo Precoppe,Joachim Müller,Gregory Afra Komlaga,Arnaud Chapuis

doi:10.3390/app10217863

Abstract

Small-size enterprises drying cassava in Africa mostly use fixed-bed dryers or pneumatic dryers. The objective of this study was to determine which of those two dryers is the best choice for this operation. Energy performance, product quality and costs were measured and analysed using a comparative experiment design. Each dryer was considered as a treatment and experiments were performed in quintuplicate at a cassava processing small-size enterprise in Ghana. The energy performance of the pneumatic dryer was superior because of the better contact between the cassava grits and the drying air, resulting in greater heat and mass transfer. The cassava flour obtained from the fixed-bed dryer had a higher Whiteness Index, but the same level of lightness, and the staff responsible for managing product quality was not able to visually distinguish them. As a result of the pneumatic dryer’s better energy performance, its operating cost was lower. The capital cost of this dryer was higher, but to recover the additional investment only 194 days of operation were needed. Therefore, it was concluded that pneumatic dryers are a better choice of equipment for cassava drying by small-size enterprises in Africa.

Highlights

Cassava (Manihot esculenta Crantz) is a perennial root crop native to South America [1] but is nowadays cultivated throughout the humid tropics [2]
The objective of this study was, to evaluate and compare the energy performance, product quality and costs of the two most common dryer types used for cassava drying by small-size enterprises in Africa
The fixed-bed dryer was in operation for 6.0 h per day producing, on average, a total of 307.1 ± 6.4 kg while the pneumatic dryer was in operation for 7.5 h per day producing, on average, a total of

Summary

Introduction

Cassava (Manihot esculenta Crantz) is a perennial root crop native to South America [1] but is nowadays cultivated throughout the humid tropics [2]. The roots are rich in starch and are the main source of calories for many people living in sub-Saharan Africa [3]. Two days after being harvested, the cassava roots become unsuitable for human consumption and post-harvest losses are high [4]. To extend cassava shelf-life, the most common practice is to process the roots into flour; a dried product that can be used later as the basis for many dishes [2]. To process cassava into flour, the roots are peeled, grated, pressed, pulverized, dried and milled [4]. Large-scale cassava processing equipment is nowadays efficient because it has been subject

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Conclusion