Experimental Research to Determine the Energy Profile in Processing Cassava (Manihot species) into ‘Gari’ in a Local Oven

The dry-frying process is the most critical operation in the processing of cassava (Manihot species)
into ‘gari”. The local technique of ‘Garification’ in batch operations was found to be most dependent on
prevailing processing temperature with regular agitation. The temperatures of customised fryer was
recorded every 3 min of the ‘garification’ process until the process is completed. The moisture content
of dewatered 5 kg mash at 40-50%, was reduced to an acceptable moisture content of 12.5% at
temperatures in the range of 27–165°C. The energy profile was found to follow a particular profile of
dehumidification for the first 7 min, evaporation cooking between 8 to 12 min, drying at about 15 to 22
min and frying for about 5 min before cooling in a 30-35 min batch cycle. A swelling index of 3.4 as a
mark of good product was achieved. The moisture content and the temperature were also influenced
by the particle size of the mash and the cake density. These series of operation occurred
consecutively and are all dependent on the prevailing temperature and duration of treatment. The
Energy profile can be used for small and medium scale design, fabrication and processing of cassava
to obtain suitable product. It can also form a precept to automation or as a complementary processing
technique in an emerging mechanized gari fryer.