CINÉTICA DE DEGRADAÇÃO DO ÁCIDO ASCÓRBICO E DA COR EM POLPAS DE TAMARINDO CONGELADAS

The knowledge of the degradation kinetics is of paramount importance to predict the loss of food quality during storage. Therefore, the objective of the present work was to study the kinetics of ascorbic acid degradation and color in tamarind pulps stored at commercial freezing temperature. The following analyzes were performed on whole pulps and added maltodextrin (10, 15 and 20%): water content, ascorbic acid and color (hue and darkening index), evaluated every 15 days for 75 days. The experimental design was completely randomized with a 6 x 4 factorial scheme (time x concentration). During frozen storage, the pulps presented an increase in water contents, this fact can be attributed to the used packaging that did not present a good barrier to the entrance of water vapor. Ascorbic acid levels decreased with storage time, and, according to the half-life of the product, the tamarind whole pulp was valid for 60 days, while the maltodextrin added pulp was extended for 75 days. The Weibull model presented a good fit to describe the degradation kinetics of ascorbic acid, where the degradation velocity was higher in the integral pulp, showing that the adjuvant used had a protective effect. Regarding the color, the averages obtained for the shade revealed that the samples had angles close to 0 °, showing red. The darkening index decreased as time progressed and the maltodextrin concentration increased. The linear regression used to describe the kinetics and color degradation in the pulps was satisfactory to provide information about the degradation rate.