INFLUENCE OF DIFFERENT FACTORS ON THE ANTIBACTERIAL EFFECT OF LIGHT EMITTING DIODES AND THEIR APPLICATION FOR THE PRESERVATION OF ORANGE JUICE AND FRESH-CUT PINEAPPLE

Abstract

This work aimed to develop the application of blue light emitting diodes (LED) for food preservation. To achieve this objective, the study was initiated by scrutinizing the effects of various factors (wavelength, temperature, pH and organic acids) that were likely to influence the photodynamic inactivation of foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes and Staphylococcus aureus) in tryptone soya broth. All the factors analyzed were observed to significantly influence the fate of the pathogens under LED illumination. Subsequently, the effect of blue LEDs was tested on Salmonella spp. in orange juice and on fresh-cut pineapples. The effect of irradiance was investigated and different mathematical models were also compared for their suitability in quantifying the photodynamic inactivation. The antibacterial efficacy of LEDs on both these foods was successfully demonstrated. Thus, this study demonstrates the potential of blue LEDs for the preservation of fruit juices and fresh-cut fruit products.