Effects of ultraviolet light and curcumin-mediated photodynamic inactivation on microbiological food safety: a study in meat and fruit

Effects of ultraviolet light and curcumin-mediated photodynamic inactivation on microbiological food safety: a study in meat and fruit:



Publication date: Available online 28 January 2020

Source: Photodiagnosis and Photodynamic Therapy

Author(s): Thaila Quatrini Corrêa, Kate Cristina Blanco, Érica Boer Garcia, Shirly Marleny Lara Perez, Daniel José Chianfrone, Vinicius Sigari Morais, Vanderlei Salvador Bagnato

Abstract

Background

About one-third of the food produced in the world is lost or wasted every year. Contamination can cause significant food loss throughout the entire supply chain, including harvesting, processing, storage, and transport to consumers. This study evaluated ultraviolet-C (UV-C) light and curcumin-mediated photodynamic inactivation (PDI) for the decontamination of meat and fruit. Methods: The cut pieces of food samples contaminated with E. coli or S. aureus were submitted to photonic treatments. For UV-C, samples were irradiated with UV-C lamps (254 nm) for 0, 1, 2, 3, 4, 5 and 10 min. For PDI, samples were incubated using 40 and 80 μM curcumin and irradiated with 450 nm at 5, 10, and 15 J/cm² of light doses. The microbiological analysis was performed by counting the colony-forming unit (CFU). Results: UV-C irradiation reduced the number of E. coli in beef by (1.0 ± 0.2) log₁₀ CFU/mL after 5 min of exposure. In chicken and pork, the numbers of E. coli were reduced by (1.6 ± 0.7) log₁₀ CFU/mL and (1.6 ± 0.4) log₁₀ CFU/mL after 4 and 10 min of irradiation, respectively. In apple the reductions were (3.2 ± 0.4) and (3.8 ± 0.2) log₁₀ CFU/mL after 5 and 10 min of UV-C irradiation, respectively. PDI (40 µM, 15 J/cm²) reduced the number of S. aureus by (1.5 ± 0.2), (1.4 ± 0.2) and (0.6 ± 0.4) log₁₀ CFU/mL in beef, chicken, and pork meat samples, respectively. In apple the greatest reduction was (2.0 ± 0.4) log₁₀ CFU/mL using 80 µM and 10 J/cm². Conclusion: UV-C irradiation and PDI had an anti-microbial effect in food and our findings indicated that the greatest effect was achieved in apples. Therefore, these techniques may be useful to reduce E. coli and S. aureus contamination levels on the surface of meats and fruits, being promising for applications in the field of microbiological food safety.