eNRTL modelling and partition of phenolics in the ATPSs {ethyl lactate (1) + potassium sodium tartrate or disodium succinate (2) + water (3)} at 298.2 K and 0.1 MPa

Abstract

Ferulic (FA) and gallic (GA) acids stand as crucial antioxidants in the cosmetics, food and pharmaceutical industries, playing a key role in the prevention of diabetes, cancer and cardiovascular diseases. The extraction of these antioxidants from by-products of the food industry, such as sweet corn residues, contributes to a more circular economy, reducing the environmental footprint associated with their extraction processes. In this work, these phenolic compounds were successfully extracted in the Aqueous Two-Phase Systems (ATPSs) {Ethyl lactate (1) + Potassium Sodium Tartrate or Disodium Succinate (2) + Water (3)} at 298.2 K and 0.1 MPa. In general, the ATPSs achieved partition coefficients (K) larger than unity, indicating a preference towards the top phase (ethyl lactate-rich), hinting a successful extraction of the phenolic compounds. Moreover, larger tie-lines generally led to higher partition coefficients and extraction efficiencies (E), promoting solute migration to the top phase. The most promising results referred to the partition of ferulic acid in Potassium Sodium Tartrate, with K = 12 +/- 3 and E = 93.3 +/- 0.4 % for the longest tie-line (TLL = 70.73 % in mass). Finally, tie-line compositions were effectively described using a generalised version of the electrolyte non-random twoliquid (eNRTL) model for double salts, presenting low standard deviations (sigma(x)) from experimental data while considering the non-randomness factor (alpha(ij)) equal to 0.2 (sigma(x) < 8.47 & sdot;10(-3)) and 0.3 (sigma(x) < 4.78 & sdot;10(-3)).