Evaluation of blanching technology in green color preservation in yerba-mate as a substitute for conventional process

Abstract

To produce enzymatic inactivation, yerba-mate leaves are exposed to heat produced by wood combustion, a step identified as zapeco. This study aimed to optimize enzymatic inactivation in yerba-mate, in a process able to replace the conventional zapeco. The effects of the variables water temperature and exposure time on the chlorophyll and colorimetric coordinates were evaluated through a factorial design 2². The adjustment of the colorimetric coordinate a* and chlorophyll as a function of temperature and exposure time allowed validation of the empirical models. The experimental condition defined by 95 °C yielded the highest chlorophyll levels and the lowest a* coordinate. Considering organoleptic aspects simultaneously with these optimized responses, the independent variable time affected the response to a lesser extent. The exposure of yerba-mate leaves to boiling water allows a product to be obtained with enzymatic inactivation and color similar to the conventional process.