Cocktail enzyme-assisted natural deep eutectic solvent for enhanced extraction of capsaicin from chili peppers: Mechanism exploration based on multi-experiments and molecular dynamic simulation

The cocktail enzyme-assisted natural deep eutectic solvent (CE-NADES) has been tailored for the efficient extraction of capsaicin, the characteristic bioactive compound of chili peppers (CPs), in this study. The extraction procedures were optimized as choline chloride:1,4-butanediol (molar ratio 1:3), extraction temperature 38 °C, liquid-solid ratio 27.5 mL/g, water content 17.8 % (v/v) and extraction time 28 min, which yield was 9.91 ± 0.13 mg/g. Moreover, CE pretreatment, by destroying plant structures, accelerated the release of capsaicin and consequently reduced the maximum decomposition temperature of CP residues to 260.5 °C after extraction. Meanwhile, more hydrogen bonds (134.72 at lifetime 3.98 ps) formed between capsaicin and NADES to facilitate the mass transfer. Larger solvent accessible surface area (210.09 nm²) and lower average interaction energy (-455.12 kJ/mol) enhanced the stability and solubility of capsaicin. Overall, CE-NADES could serve as an industrialized and green alternative method for the efficient extraction of capsaicin.