The processing of cassava roots in HQCF involves peeling, washing, grating, pressing, disintegration, sifting, drying, milling, screening, packaging and storage.
High quality cassava flour (HQCF) is simply unfermented cassava flour. It can be used as partial replacement for many bakery and pasta products. Several sources report that at least 10per cent of the wheat flour used for baking can be substituted by cassava flour without any change to the taste or other qualities. The substitution ratio greatly depends on the quality of the cassava flour. Edible cassava flour is packed, transported and stored in containers, which will safeguard the hygienic and organoleptic qualities of the product.
The following stages depicted in Figure 2 are required in the production of HQCF:
Cultivating and harvesting - Matured low moisture cassava varieties should be selected for processing since these offer higher recovery rates and starch quality of the flour.
Peeling and washing - Peeling is usually done manually with a knife and is necessary so that the final product is free of fragments. Washing with clean water is required to remove soil particles and dirt which would mar the quality of the product.
Grating and Pressing - Grating is carried out using a motorized cassava grater. It disintegrates the cassava tissue and frees up moisture so that pressing is efficient. Pressing is carried out with either a manual screw or hydraulic press to dewater the product to facilitate drying. Pressing time should be helps short to avoid fermentation of the grated mash leading to an acidic taste to the product. Pressing also removes much of the yellow coloring of cassava tissues leading to a more acceptable whiter product.
Drying may be either by sun/natural or artificial methods. For sun and artificial drying the loading should not exceed 1.5kg/m2 and 2.5kg/m2 respectively. The lower the loading density, the more rapid the drying and the higher the quality of final product.
Milling, Screening and Packaging - Dried grits are milled in a hammer or disc attrition mill to a fine and uniform particle size.. Flour is screened using a motorized flour sifter fitter with a 250µm screen. This removes fiber and improves the smoothness of the flour. Bulk handling of the final product should be in polyethylene lined polypropylene sacks. Adequate packaging is needed to avoid moisture uptake of HQCF and attack by pests during storage. Storage should be in well ventilated rooms and fit for purpose.