Co-crystallization of curcumin with tyramine resulted disparate impacts on the activities of photodynamic and sonodynamic treatments

Curcumin, a plant-derived phenolic compound, has emerged as a promising photo/sonosensitizer within food industry. However, the low aqueous solubility greatly restricts its practical application. Here, we utilized co-crystallization strategy to develop a curcumin-tyramine cocrystal with enhanced solubility (98.53-fold increase over curcumin) and characterized its physicochemical properties using FT-IR, SEM, and XRD. Moreover, the results also showed curcumin-tyramine cocrystal maintained comparable antimicrobial photodynamic activity to that of curcumin (2.44 ± 0.36 vs 3.24 ± 0.42-log decrease in CFU/mL); however, its sonodynamic inactivation efficacy was marked diminished (only exhibiting a 0.46 ± 0.11-log reduction in CFU/mL), suggesting co-crystallization may resulted disparate impacts on activities of photodynamic and sonodynamic treatments. Considering high penetrative ability of ultrasound to activate sensitizers within foods often gives sono/photodynamic treatment an edge over photodynamic treatment alone in food sterilization, our findings suggested the potential imbalanced influence of modification process on photodynamic and sonodynamic activities of sensitizers should not be overlooked when modifying the sensitizers.