STABILITY OF VITAMIN C-FORTIFIED YERBA MATE AND SENSORY EVALUATION OF THE DRINK

Abstract

ABSTRACT The purpose of this study was to analyze the viability of elaborating a vitamin C-fortified yerba mate in its usual forms of commercialization: packages for traditional mate and packages for infusions. Formulation was made with the purpose of preserving the sensorial characteristics of food, without altering the technological aspects of its elaboration process. Results of sensorial evaluation indicated that there were no differences between the vitamin C-fortified yerba mate and the non-fortified ones. Loss of ascorbic acid in fortified yerba mate during storage at different environmental conditions was studied. The effect of temperature (30 and 40C) and water activity (aw: 0.71, 0.8 and 0.91) were analyzed. Degradation was appropriately described with a first-order kinetic. The k rate coefficient showed dependence on temperature and humidity; its value was increased approximately 10 times when the relative humidity (RH) changed from 71 to 80%. Thus, the ascorbic acid content was reduced to half of its initial value after 128 days of storage at 30C and 73%, whereas the same decrease happened after 13.5 days of storage at 30C and 80%. The effect of temperature on the rate constant is more important in an aw range of 0.8–0.91 than in an aw range of 0.71–0.8. PRACTICAL APPLICATIONS The present work demonstrates the viability of elaborating a vitamin C-fortified yerba mate and preserving the sensorial qualities of the drink without altering the technological aspects of its elaboration process. An important contribution of the present work is the quantification of the degradation kinetics of ascorbic acid in fortified yerba mate during storage, a necessary parameter for quantifying the shelf life of the packaged product.