Estudo da cinetica de desidratação por imersão e secagem de tomate cereja (Lycopersicon esculentum var. cerasiforme)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

The drying kinetics of fresh and osmo-dehydrated cherry tomato (Lycopersicon esculentum var. cerasiforme) was studied in this research. The effect of pre-treatment, temperature and velocity of the air was analysed. The osmotic dehydration was studied using a sodium chloride and a mixed sodium chloride-sucrose solutions at 10 and 25w/w and at room temperature. The effect of the osmotic agent and solution concentration was studied in order to choose the best conditions of this process before drying. The experimental values of sorption isotherms at 50 and 70.C for fresh cherry tomato were obtained at relative humidity ranging from 10.75 to 81.20%, and at 50. C for the osmotic dehydrated fruit, with relative humidity ranging from 11.10 to 81.20%, and correlated by BET, GAB, Halsey and Oswin models. GAB model presented the best fitting for fresh fruit and Halsey model presented the best correlation to the dehydrated cherry tomato. The experimental drying curves were obtained at 50, 60 and 70.C and air velocities of 0.75 and 2.60 m/s in a static dryer. The relative humidity ranged from 28 to 42%. The drying curves were fitted usind Fick s second law for the infinite levei slab without considering shrinkage and using Page s equation. The best correlation was given by Page s equation. The effective diffusivity ranged from 0.73 to 2.10 m2/s for fresh fruit and from 0.81 to 1.60 m2/s for osmotic ,dehydrated tomato. Evaluation of the final product was done by means of density, ascorbic acid content and rehydration, in comparison to the fresh fruit.

ASSUNTO(S)

secagem desidratação tomate

ACESSO AO ARTIGO

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