Effect of Processing Parameters on Foam-mat Drying of Tomato (Solanum lycopersicum).

Abstract

Tomato is one of the most important fruit crops in the world; It is also very nutritious as it contains many essential nutrients. However, they are highly perishable and cannot be stored for very long in their raw form. In this study, tomato was dried using foam mat drying method with glycerol monostearate as foaming agent. The research was conducted using foaming agent ranging from 1- 3%, drying temperatures ranging from 65-75°C and whipping time of 3-7minutes. Design Expert Statistical Package was used to develop the experimental design. The proximate composition of the foam mat dried tomato was determined and its sensory evaluation was investigated. The results obtained ranged as follows: moisture content 19.84 - 16.94%, crude fibre 3.5-8.7%, crude protein 0.5-2.8%, fat content from 12.18 – 25.12%, ash content 10.01-20.5%, carbohydrate content 41.71 – 53.30%, vitamin content ranged from 2.65-4.99mg/100g. The result of the statistical analysis carried out indicated that the concentration of foaming agent had significant effect (p < 0.05) on the odour and ash content of the tomato powder but did not have significant effect (p>0.05) on the other properties. The whipping time had no significant effect (p>0.05) on any of the properties of tomato powder. The drying temperature had significant effect (p < 0.05) on moisture content, crude fibre, fat, β-Carotene, odour and taste of the tomato powder. Thus, foam mat drying using glycerol monostearate is effective in retaining the nutritional and organoleptic qualities of tomato.