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

Abstract

The efficacy of photoactivated curcumin in decontaminating food surfaces using a 465 nm 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 1.5 × 105 cfu/cm2 was estimated to be 1.60 × 10−3 M, combined with irradiation of 27.2 J/cm2 at 465 nm. Bacterial inactivation kinetics could be described by a Weibull model (R2 = 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 applications The 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.

The Remarkable Effect of Potassium Iodide in Eosin and Rose Bengal Photodynamic Action against Salmonella Typhimurium and Staphylococcus aureus

“…They observed that the aPDI were able to eliminate a 4 log CFU/cm 2 of bacterial population. The results of these studies showed that no negative effects were observed in the food matrices [22,44].…”

“…The authors observed a reduction in E. coli population, as well in the activity of the enzymes polyphenol oxidase and peroxidase. Aurum and Nguyen [44] achieved a 2 log inactivation of E. coli on grapes treated with curcumin at 1.6 µM. The grapes were immersed in curcumin solutions containing the inoculum for 60 min and the samples were afterwards irradiated with a blue LED light (465-470 nm).…”

Impact of Curcumin-Mediated Photosensitization on Fungal Growth, Physicochemical Properties and Nutritional Composition in Australian Grown Strawberry

“…The results are supported by refractometer analysis of TSS which showed a 9% increase (p < 0.05) in photosensitized fruits compared to the control (Table 1). Aurum and Nguyen (2019) reported an increase in TSS in grapes treated with curcumin-based photosensitization at a light dose of 36.3 J/cm 2 up to 4 days of storage at 37°C. This increase could be caused by dehydration (Valverde et al 2005) and activity of hydrolytic enzymes (Nabifarkhani et al 2015).…”

Control Measures for SARS-CoV-2: A Review on Light-Based Inactivation of Single-Stranded RNA Viruses

“…For instance, the antimicrobial potency of blue LED has been demonstrated against several pathogenic bacteria, such as Salmonella spp. [ 176 , 177 ], Listeria monocytogenes [ 176 , 177 , 178 , 179 , 180 ], E. coli [ 181 , 182 ], and bacterial endospores ( Bacillus cereus , B. subtilis , and Clostridium difficile ) [ 183 ]. Generally, the mechanism of blue light sanitization is associated with the absorption of the light by photosensitizers, especially the endogenous porphyrin ( Figure 4 ) [ 35 ], which can result in the generation of ROS [ 184 ].…”