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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/7541

Title: Standardisation of the grating surface of cassava graters for gari
Authors: Opandoh, Deborah
Issue Date: 13-Jul-2015
Abstract: Cassava is the third largest source of food carbohydrates in Africa after rice and maize. It is drought tolerant and gives reasonable yields where other crops do not grow well, thus, acting as a famine reserve. Nonetheless, cassava undergoes post harvest physiological deterioration (PPD) after three days of harvest. Therefore, there is the need to process it within three days after harvesting. Grating of cassava is one of the popular means of processing. Cassava is grated and processed into gari; a popular meal in West Africa, especially in Ghana and Nigeria. Modifications have been made on graters to improve and increase its efficiency. However, it is observed that, there is no standard in the making of the grating surface (teeth) of these graters. Manufacturers of these graters sometimes produce the teeth in a dense random form. Materials for making these food processing surfaces are usually mild steel which rust with time although stainless steel is sometimes seen. The grating of cassava for gari does not always give the desired size of mash. Replacement of teeth is somewhat cumbersome as there is no laid down procedure for making the grating surface; thus, the need to standardize the grating surface of the cassava grater. In this project, a survey was done to know the existing patterns of cassava grating surfaces in three regions of Ghana; Western, Central and the Ashanti regions. From the knowledge gathered from surveys and review of literature, three grating surfaces were designed and fabricated. They were tested on an already existing grater design. Results after the mash was made all the way into gari by a particular processor (to ensure some level of consistency) were compared to three already existing teeth, two of which were saw toothed and the other punched using a mechanical shaker. In the process of standardizing the grating surface of the cassava grater, important factors such as tooth size, inter tooth spacing, tooth angle and material type were considered. The recommended tooth diameter was ±0.04mm from 3.01mm while the inter tooth spacing vii was ±0.08mm from 8.05mm. The brick form of arrangement of teeth is also preferred to ensure effective contact between the cassava and the grating surface.
Description: A thesis submitted to the Department of Agricultural Engineering Kwame Nkrumah University of Science and Technology in partial fulfillment of the requirements for the award of Master of Science (Food and Post Harvest Engineering) College of Engineering, 2015
URI: http://hdl.handle.net/123456789/7541
Appears in Collections:College of Engineering

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