Evaluation of the efficacy of a family sized solar cabinet dryer in food preservation

Abstract

A family size solar cabinet dryer was designed, constructed and its performance evaluated using cassava roots. Wooden, metallic and glass materials were used for the construction of the familysized solar dryer and freshly harvested cassava roots used to evaluate the drying efficiency of the system in the preservation of cassava and cassava-based products. The proximate composition of the cassava roots including its cyanide content, mould count, pH and water activity before subjecting it to the two modes of drying used in this research were noted. The cassava roots were peeled, cut into chips of 4cm long, 1cm wide and 1cm thick, washed and divided into 5 parts, 3 parts were soaked separately for 1, 2 and 3 days respectively, while the other 2 parts were sundried and solar-dried for 3 days. Samples were collected every day to determine the pH, water activity and moisture content. For the soaked samples, after each day of soaking, they were divided into 2 parts; 1 part was sun dried and the other was solar dried. The pH, water activity and moisture content, mould count and cyanide contents of the various samples were determined. Results obtained show that soaking and solar-drying reduced the cyanide and mould counts in cassava more than soaking and open-air sun-drying. Data obtained from the sensory evaluation showed that the colour and odour of all the solardried samples were preferred to those of the sun dried samples.