When tomatoes are submitted to treatments of drying, depending on the parameters and methods used, the concentration or degradation of nutrients can occur. The changes in the composition and colour were verified when different drying processes were used. Freeze drying, oven drying, the combination of both and also the effect of the pretreatment (blanching) using steam were studied. The fresh tomato composition was compared with the composition of dehydrated tomato powder. After dehydration, the moisture content reduced 78% from the total initial moisture. In addition, a nutrient concentration was observed with an increase of about 57% of citric acid content and 3% in the pH. The ash content also increased from 0.53% to 8% (15 times) and 60%, the carbohydrates from 3.94% to 60% (15 times) and the proteins were increased from 1% to 11% (10 times). The blanching resulted in different types of changes, such as greater stability for the proteins, carbohydrates, fat, lycopene and beta-carotene.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fed Univ Technol, Fed Technol Univ Parana UTFPR, Dept Prod Engn, BR-84016210 Ponta Grossa, PR, BrazilUNESP, Inst Chem, Dept Phys Chem, BR-14800900 Araraquara, SP, BrazilUniv Estadual Ponta Grossa, Dept Mat Engn, BR-84030900 Ponta Grossa, PR, BrazilUNESP, Inst Chem, Dept Phys Chem, BR-14800900 Araraquara, SP, Brazil