CO2-NBs- assisted enzymatic hydrolysis as a new green approach for extraction of phenolic compounds from rhizomes of Polygonatum cyrtonema Hua

Summary The integration of carbon dioxide-nanobubbles (CO 2 -NBs) with cellulase has led to the development of an innovative extraction system for phenolic compound retrieval from P. cyrtonema (Polygonatum cyrtonema) Hua rhizomes. Four critical factors influencing on CO 2 -NBs-cellulase were methodically investigated and optimised through single-factor experiments. The optimal experimental conditions are 30 cycles, 0.35 MPa, pH 5.45 and 0.025 g/mL cellulase aqueous solution. The stability of system was characterised meticulously, indicating the viability for at least 24 h. Comparative assessment of bioactive constituents and antioxidant activity demonstrated exceptional extraction efficiency and potential synergistic effects of CO 2 -NBs-cellulase. Synergistic effects and reaction mechanisms during extraction were explored using Fourier-transform infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy, which contributed to mechanism understanding with significant alterations in partial structure and heightened thermal stability we found. In essence, this study introduces an eco-friendly, energy-efficient extraction system paradigm based on a novel nanobubble-enzyme binding approach.