Switchable Deep Eutectic Solvents for the Green Extraction of Tea Saponins From Camellia Oleifera Seed Meal

J Sep Sci. 2025 Jan;48(1):e70082. doi: 10.1002/jssc.70082.

Abstract

Tea saponin has garnered tremendous interest for its potential use in surfactant and drug synthesis. This research was designed to develop a technique based on pH-responsive switchable deep eutectic solvents (SDESs) for extracting tea saponins from Camellia oleifera seed meal. SDES synthesized from hexanoic acid and triethanolamine (1:1 molar ratio) offered the optimum extractive performance and the optimal conditions were obtained through single-factor experiments: 30 wt% water content in SDES, solid-liquid ratio of 1:30 g/mL, 60°C extraction temperature, 30 min extraction time, and acid volume of 1500 µL. The extraction yield was 162.14 mg/g after optimization, which increased by 15.65% and 9.47% compared to water and ethanol extraction methods, respectively. After pH adjustment, 98.95% of the tea saponins were recovered in the bottom phase. After precipitation and freeze-drying procedures, the purity of the tea saponin solid was 62.9%.

Keywords: Green extractants; bioactive compounds; extraction; switchable deep eutectic solvents; tea saponin.

MeSH terms

  • Camellia* / chemistry
  • Deep Eutectic Solvents / chemistry
  • Plant Extracts / chemistry
  • Plant Extracts / isolation & purification
  • Saponins* / chemistry
  • Saponins* / isolation & purification
  • Seeds* / chemistry
  • Tea / chemistry

Substances

  • Saponins
  • Deep Eutectic Solvents
  • Tea
  • Plant Extracts