Highly efficient isolation and purification of high‐purity tea saponins from industrial camellia oil production by porous polymeric adsorbents

Abstract

BACKGROUNDRecovery of high‐purity tea saponin (TS), a promising non‐ionic surfactant with well‐documented properties, is one of the major challenges to broadening its industrial applications. In this study, an innovative and sustainable strategy for the highly‐efficient purification of TS was developed by using well‐designed highly‐porous polymeric adsorbents.RESULTSThe prepared Pp‐A with controllable macropores (~96 nm) and appropriate surface hydrophobic properties was found more favorable for achieving high adsorption efficiency towards TS/TS‐micelles. Kinetic results showed the adsorption follows the pseudo‐second‐order model (R2 = 0.9800), and the Langmuir model is more qualified to explicate the adsorption isotherms with Qe‐TS ~ 675 mg g−1. Thermodynamic studies revealed the monolayer adsorption of TS was an endothermic process that was conducted spontaneously. Interestingly, ethanol‐driven desorption (90% v/v ethanol) of TS was rapidly (< 30 min) complete due to the possible ethanol‐mediated disassembling of TS‐micelles. A possible mechanism that involves the interactions between the adsorbents and TS/TS‐micelles, the formation and disassembling of TS‐micelles was proposed to account for the highly efficient purification of TS. Afterwards, Pp‐A‐based adsorption method was developed to purify TS directly from industrial camellia oil production. Through selective adsorption, pre‐washing, and ethanol‐driven desorption, the applied Pp‐A enabled the direct isolation of high‐purity TS (~96%) with a recovery ratio > 90%. Notably, Pp‐A exhibited excellent operational stability and is of high potential for long‐term industrial application.CONCLUSIONResults ensured the practical feasibility of the prepared porous adsorbents in purifying TS, and the proposed methodology is a promising industrial‐scale purification strategy. © 2023 Society of Chemical Industry.