Effects of curcumin-based photodynamic treatment on the storage quality of fresh-cut apples.

Photodynamic treatment (PDT) is an innovative technology with non-thermal and environmentally sound merits, but the evaluation on the storage qualities of fresh produce was scarce. In this study, the effects of curcumin-based PDT on the quality of fresh-cut 'Fuji' apple slices during storage at 4 °C were investigated. The impacts on the survival of Escherichia coli, color and weight loss were examined under different curcumin concentrations, illumination time or incubation time. Curcumin-based photodynamic inactivation of E. coli on the surface of apple slices reached 0.95 log. Curcumin-based PDT was proven to prevent browning and weight loss. Additionally, PDT significantly reduced the activity of polyphenol oxidase and peroxidases to 48% and 51%, respectively. Moreover, there were few negative changes in total phenolic, ascorbic acid content and anti-oxidant activity of the treated apples. These results indicated that curcumin-based PDT was a viable and promising non-thermal technology to preserve the quality of fresh produce.