Temperature-dependent convection induced incremental extraction of anthocyanins from Melastoma dodecandrum Lour. Based on recyclable natural deep eutectic system

Melastoma dodecandrum Lour. (MDL) contains abundant anthocyanins. Choline chloride-oxalic acid (ChCl-OA, 1:1) was selected for the temperature-dependent convection induced incremental extraction of anthocyanins from MDL. The regulating effects of MDL anthocyanins on gut microbiota were studied by analyzing the diversity in C57BL/6 J mice. The results showed that under optimized conditions (ultrasonic power of 310.4 W, extraction temperature of 59.9 °C, cold-stimulation time of 9.0 min, extraction time of 29.8 min), the yield of anthocyanins (Y A ) achieved the highest level at 60.28 ± 1.05 mg CGE/g DW, outperforming non-incremental approach by 58 %. The ratio of Y A obtained from the fifth regeneration of ChCl-OA to initial Y A was over 90 %. Eight anthocyanins were identified in incremental extracts, over four anthocyanins in non-incremental extracts. The ChCl-OA system achieved equilibrium at 3.5 ps with energy of −1002.22 kcal/mol. More hydrogen bonds number (128) and longer lifetime (6.72 ps) resulted in a larger diffusion coefficient of anthocyanins at 0.10 m 2 /s. The 60 mg/mL of anthocyanins increased the α-Diversity (Sobs) and Gut Microbiome Health Index (GMHI) by 22 % and 56 %, respectively, harmonizing the gut microbiota. Therefore, this recyclable ChCl-OA based incremental extraction has unveiled horizons for the green and sustainable production of MDL anthocyanins.