Intensified Multistep Extraction of Phenolic Compounds from Yerba Mate (<i>Ilex paraguariensis</i>) Leaves: A Techno-Economic and Environmental Approach.

Abstract

In the current work, an alternative intensified methodology for the extraction of phenolic compounds from yerba mate is proposed, considering the use of sequential multistages. Conventional single-stage extraction was optimized in its key parameters (temperature and solid/liquid ratio), and its kinetics were evaluated. The multistage extraction process was evaluated considering two and four stages, considering the results on the antioxidant potential of the final extract. A scale-up simulation was conducted, considering the processing of 25 kg of yerba mate a day, and economic and environmental aspects were considered. The best extraction condition was achieved at 70 °C with 0.5 g yerba mate 100 mL^-1 water. Intensified multistage processes and conventional ones resulted in final extracts with similar antioxidant potential (493.0-526.5 mg GAE L^-1), highlighting that the three processes can be used for the obtention of the same product. Regarding the economic aspects, using the multistage extraction processes results in a considerable decrease in the Total Capital Investment of a yerba mate plant extract. Finally, environmental analysis shows that the multistep process is more eco-friendly than the conventional one, as it exhibits considerably lower energy consumption and lower CO₂ emissions. The intensified multistage extraction process is a green and eco-friendly alternative to conventional extraction processes, with potential for implementation in several plant extract industries.