Secagem da banana da terra (Musa sapientum L.) com pré-secagem osmótica para elaboração de chips.

Abstract

The transformation of perishable fruits into new products, with bigger shelf life, becomes an alternative to food industry. The osmotic pre-drying followed by complementary drying is a big industrial potential technique. Thus, this work aims to: a) Study the banana osmotic predrying in osmotic concentrations of 1:10. 1:15 and 1:20, in thickness of 1,0; 1,25; 1,5 and 1,75 mm; b) Accomplish an sensorial analysis of the fried bananas to determine the ideal thickness and the best sodium chlorite concentration to develop banana chips; c) Study the complementary drying kinetics of banana chips, softly fried in fixed bed dryer at the temperatures of 60, 70 and 80 °C and in microwave oven, at the potencies of 220, 330 and 440 W; d) Accomplishment of a final sensorial analysis with relationship to the attributes: appearance, color, smell, taste, crispy and salt content of the banana chips. The methodology consisted in immerge green banana slices of several thickness in osmotic solution with different concentrations of NaCl to define the osmotic treatment time. When the time was defined, an osmotic pre-drying was did again, followed by a softly fry with a complementary drying in fixed bed dryer and in microwave oven. After the drying, a sensorial analysis was done to evaluate the final product. From the obtained results, it can be concluded that: a) About the osmotic pre-drying kinetics in different thickness and sodium chlorite concentrations: There is a tendency of increasing the drying coefficient "k" with the increase of the green banana slice thickness for the three studied concentrations of sodium chlorite; the best time for osmotic treatment was the period of three hours, after this time a chemical constituent loss was observed. B) About the sensorial analysis for the attributes: appearance, color, smell, taste, salt content and crispy, the testers attributed, in general, the best notes to the banana chips elaborated with osmotic pre-drying with sodium chlorite concentration of 1:15 for three hours, with thickness of 1,0 mm to define the ideal thickness of the banana chips and the best sodium chlorite concentration, c) About the banana chips complementary drying kinetics in fixed bed at the temperatures of 60, 70 and 80 °C and in microwave oven at the potencies of 220, 330 and 440 W, the best determination coefficient "R2" was obtained through Page's equation, among the proposed equations; d) The preference was obtained by the testers when the banana chips were elaborated from an osmotic pre-drying with NaCl concentration of 1:15 for 3 hours and a softly fry, followed by a complementary drying in a fixed bed dryer at the temperature of 70°C or in a microwave oven with potency of 330W, for almost all attributes (appearance, smell, taste, salt content and crispy) except the color attribute in that the preferred banana chips was the one dried at the temperature of 80°C.