Secagem e armazenamento do tomate em pó.

Abstract

The drying of tomatoes in the temperatures of 50, 60 and 70ºC and conservation of the dry material under storage conditions was studied. For storage, the samples dried at 70ºC were triturated for transformation in tomato powder. The tomato powder was divided in two lots: without addictive (control), and added with the tricalcium phosphate antihumectant. Each lot was packaged in low density polyethylene bags with 20 g each and stored during 60 days. The physical-chemical characteristics soluble solids (ºBrix), pH, moisture, ascorbic acid, titratable acidity, ash, insoluble ash in chloride acid, reducing sugars, alcoholic extract and the parameters of color brightness (L *), redness (+a *) and yellowness (+b*) were determined each ten days. The moisture adsorption isotherms of tomato powder at 10, 20, 30 and 40ºC were also determined. The results obtained of the physical-chemical determinations of tomato in natura and of the tomato powder demonstrated reduction of moisture of 94.89 to 13.85%, with increase of soluble solid, ascorbic acid, titratable acidity, ash, reducing sugars and alcoholic extract. During the storage of the tomato powder there was not, for none of the two treatments, alteration in the ascorbic acid, titratable acidity, ash, soluble solids, pH and alcoholic extract, but it occurred reduction in the reducing sugars in both treatments. The moisture of the tomato powder increased with the time of storage for the control. The brightness decreased with the time of storage in both treatments; the redness and the yellowness decreased with the time to the control, while for the treatment with tricalcium phosphate there was not alteration. The smallest time of drying of the tomatoes was reached at 70ºC. Page models, Wang & Singh and Henderson were fitted the experimental curves of drying well, with determination coefficients (R2) above 0.94. The Halsey, GAB and modified BET models fitted well the moisture adsorption isotherms of the tomato powder, presenting R2 above 0.97% and mean relative deviation modulus (P) below 5.19%.