Smart membranes production by supercritical phase inversion to increase food shelf-life

The freshness of minimally processed foods is also determined by their appearance; browning due to oxidative phenomena is one of the main reasons of discarded by consumers. To overcame this problem, the development of antioxidant active packaging has gained increasing interest in the food industry. In this work, a supercritical phase inversion process was tested to produce Curcumin (Cu) loaded Cellulose Acetate (CA) membranes, to be inserted in food packaging as antioxidant devices. Active membranes were produced at different process conditions (pressures ranging between 150-250 bar and temperatures ranging between 35-55 °C), polymer amount (12, 18, 24% w/w) and at constant ratio Cu/CA (10% w/w). Cu-loaded membranes showed an homogeneous cellular morphology with a mean pore size lower than 12 μm. Cu release was measured and a maximum release time of about 2 days was obtained; moreover, antioxidant tests were also performed on the loaded membranes, showing an activity up to 90%.