Decaffeination of yerba mate by supercritical fluid extraction: Improvement, mathematical modelling and infusion analysis

This work aimed to improve yerba mate caffeine extraction process, considering three independent variables, carbon dioxide flow, ethanol flow and extraction time, in three levels. The following process parameters were kept constant: pressure (300 bar), temperature (60 degrees C), and particle size (0.428 mm). The Box-Behnken experimental design was carried out for 15 extractions and the optimized condition to obtain decaffeinated yerba mate was as follows: 950 g/h of the carbon dioxide flow; 106 g/h of the ethanol flow; 4.25 h of the time. Under these conditions, it was possible to obtain processed yerba mate with 0.16% +/- 0.06% (g(caffeine)/g(yerba mate)). Furthermore, the removal of caffeine from yerba mate did not decrease the antioxidant capacity of extracts obtained by infusion, as well as cell viability tests showed that both extracts decreased cell viability in esophageal cancer. These results indicate that decaffeinated yerba mate maintains that properties found in traditional yerba mate. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study aimed to improve the caffeine extraction process of yerba mate and successfully obtained decaffeinated yerba mate with maintained antioxidant properties. Furthermore, cell viability tests showed that extracts from decaffeinated yerba mate decreased cell viability in esophageal cancer cells.