Green extraction of anthocyanins from Chinese bayberry (Myrica rubra Sieb. Et Zucc.) using acidic deep eutectic solvents: Enhancing the physicochemical properties and stability of anthocyanins.

In this study, we used Chinese bayberry residue as the raw material to extract anthocyanins using deep eutectic solvents (DESs). We screened for an efficient ADES-betaine & citric acid (Bet-CA), and coupled it with ultrasound for the extraction of anthocyanins. We delved deeply into the relationship between the physicochemical properties of deep eutectic solvents and their extraction efficiency of anthocyanins, and studied its degradation kinetics under different temperatures and light conditions. This provides a green, efficient, and multi-stability protective strategy for the recovery of anthocyanins from plant-based by-products. The results revealed that the total anthocyanin content (TAC) extracted using HB47 was 7 times higher (7.05 mg CGE/g DW) than that extracted using the conventional acidified ethanol solvent (1.05 ± 0.05 mg CGE/g DW). Correlation analysis demonstrated a significant positive correlation (p < 0.01) between TAC and a⁎. The extracts were subjected to heat treatment at different temperatures and stored different light conditions. HB47 exhibited the highest degradation rate (k = 0.1169) at 80 °C. However, it showed the greatest stability at lower temperatures, particularly at 4 °C (k = 0.0016, t½ = 433.22 h). After 7 days of storage in darkness, the preservation rate of anthocyanins extracted by different solvent systems remained above 90 %. While the loss rate under UV light exposure reached as high as 95 %, significantly higher than that under sunlight.