Extraction of Chromophoric Compounds from Acer palmatum Leaves: Optimization of Ternary Deep Eutectic Solvent-Assisted Extraction Process and Chromophore Stability Study

Abstract

In this study, red leaves of Acer palmatum were used as raw material. A ternary deep eutectic solvent (DES) was used for auxiliary extraction, with the optimal extraction condition ranges determined by single-factor experiments. Then the process was optimized via response surface methodology (RSM). Using dye absorbance as the evaluation index, the acid-base stability, thermal stability, and light resistance of Acer palmatum extract were investigated, and the compounds in its dye were identified. The optimal extraction process was: a solid-to-liquid ratio of 1:15 (w:v), an extraction time of 112 min, a moisture content of 86%, and an extraction temperature of 42 °C. Fourier transform infrared spectroscopy analysis and stability tests were also conducted. Ternary DES extraction of Acer palmatum dye is a pollution-free, low-energy and sustainable process, providing practical reference for expanding the industrial application of natural dyes.