Light-emitting diode assisted non-thermal pasteurization of Punica granatum L. juice

Light-emitting diode (LED) technology is a novel non-targeted processing technique that uses light energy for the disinfection of food products. It has been known for antimicrobial efficacy by aiding the principle of photosensitization to deactivate the microorganisms causing food spoilage without altering organoleptic and nutritional assets. Pomegranate juice is a rich source of polyphenolics, which are prone to degradation in thermal pasteurization. The current research develops a non-thermal pasteurization method for pomegranate juice using blue LED at 470 nm wavelength, at different temperatures (5, 15, and 25 degrees C) and exposure gaps (2, 5, 8 cm). The sub-lethal injury for Escherichia coli was around 91.7% at 5 degrees C, and 94.87% at 15 degrees C. The LED exposure at 25 degrees C significantly increased the sublethal injury from 15.4% at 2 h to 34.59 at 4 h and 84.63% at 10 h time. The total flavonoids compounds for the 5 degrees C/2 cm sample showed a significant increase of 1.66 times higher than the control. Novelty impact statement The loss of organoleptic properties due to thermal pasteurization treatments of fruit products has increased the applications for non-targeted process methods like light-emitting diodes (LED). The LED treatment of pomegranate juice has shown a sub-lethal injury rate of 94.87% at 15 degrees C storage temperature. The total flavonoids have been elevated 1.66 times after treatment at 5 degrees C at a 2 cm exposure gap.