Concentration of phenolic compounds in aqueous mate (Ilex paraguariensis A. St. Hil) extract through nanofiltration

In order to establish the parameters to obtain aqueous mate extract with the highest content of total phenolic compounds (TPC), the response surface methodology (RSM) was used. The extract obtained at 100 °C, within 3 min and with pH of 6.0 was submitted to nanofiltration to concentrate the phenolic compounds of mate (Ilex paraguariensis A. St. Hill). The total phenolic content values in the permeate and in the concentrate collected in different volumetric reduction factors (VRF) were different from those detected in the feed extract. The concentration of phenolic compounds increased when VRF was increased, reaching the highest retention index (R) of 0.99 when VRF was 4.0. The permeate and the concentrate obtained in VRF 4.0 were verified through HPLC. 4,5-dicaffeoylquinic acid and gallic acid showed retention index of 1.00 and 0.95, respectively, while 3,4-dihydroxybenzoic acid and chlorogenic acid reached 0.99 and 0.98, respectively.

► Response surface methodology was used to optimize the aqueous extraction from mate. ► Concentration of phenolic compounds in aqueous mate extract by nanofiltration. ► The quality of nanofiltration was evaluated according to the total phenolic content. ► The nanofiltration was a good alternative for concentrating aqueous mate extract.