Curcumin loaded nanobubbles for food preservation: Experimental and mathematical models.

Due to microbial contamination, fruits keep intact turgidity, colour and texture of the freshly picked products for a limited time on market shelves, generating waste and requiring the use of pollutants. Curcumin, a natural component of Curcuma longa$, is a potent biodegradable antibacterial agent. Moreover, it is an effective photosensitizer able to induce photodynamic activation in blue light (400-500 nm wavelength), producing Reactive Oxygen Species (ROS) which cause bacteria death. Unfortunately, curcumin is poorly soluble in water, but is effectively deliverable by nanocarriers. Chitosan-shelled nanobubbles (NBs) are safe and resistant nanocarriers which could transport and gradually release curcumin on fruits' surface. In our preliminary experiments, different NBs formulations were tested in order to improve the release process and antibacterial ability against E. coli, S. aureus and E. faecalis, both with and without blue light photoactivation. A mathematical model based on previous data has been formulated to optimize the processes for maintaining bacterial proliferation under a fixed threshold, simulating an industrial context and by scaling the NBs manufacturing.