Efficacy of photoactivated curcumin to decontaminate food surfaces under blue light emitting diode

The efficacy of photoactivated curcumin in decontaminating food surfaces using a 465nm light emitting diode (LED) light source was investigated. Under studied conditions, LED illumination alone had negligible antibacterial effects while photoactivated curcumin exhibited strong bactericidal activities against Escherichia coli. Minimum inhibitory concentration of photosensitized curcumin against E. coli on nutrient agar surface at a concentration of 1.5x10(5)cfu/cm(2) was estimated to be 1.60x10(-3) M, combined with irradiation of 27.2 J/cm(2) at 465nm. Bacterial inactivation kinetics could be described by a Weibull model (R-2=0.979-0.999, RMSE=0.019-0.229). When the treatment was applied on grape surface, the efficiency was lower as compared to that on the agar surface. Photoactivation enhanced quality retention of the samples during storage with significant preservation of vitamin C, color, texture, and reduction of weight losses. Practical applicationsThe study provides an alternative method for food surface decontamination. Inactivation of pathogens and spoilage microorganism by combined visible LED light source and natural photosensitizers minimizes the adverse processing effects on organoleptic and physicochemical quality of the treated foods. The approach could be further optimized, scaled up, and applied in food industries.