Dry cherry tomato: innovation from studies on isotherms

Abstract

The drying of vegetables is a very ancient practice for food preservation still in use nowadays. Tomatoes cut into two parts, added with salt and dried are an important element of the food tradition in south of Italy. The tomato’s drying in Sicily is still carried out with a sun-drying process, with an empiric method. The final product obtained has a high quality which it is not homogeneous. In addition to dried products, the market offer even semidry products, to limit the loss of the nutritional characteristics of the dried product. The semidry product is a special category of dehydrated products that have a residual moisture content about 30%; for this reason, nutritional product characteristics may be are best preserved. Drying experiments of tomatoes were conducted at different final moisture content. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during all drying process. Isotherms were carried out with the AquaLab Vapor Sorption Analyzer. The aim of this study is: • •the optimization of the drying process in a pilot plant fold under different temperatures conditions; • •the study of adsorption and desorption isotherms to better understand the drying process; • •to obtain semidry product and dry products comparable for nutritional and sensorial characteristics, monitoring some of the basic chemical parameters, the trend of the main nutrients of tomato during the drying process and the sensory parameters.