novel technologies for preserving ricotta cheese: effects of ultraviolet and near-ultraviolet–visible light

Ricotta cheese is a potential growth medium for a wide range of microorganisms. The aim of the current study was to investigate the efficacy of ultraviolet (UV-C) and near-ultraviolet–visible light (NUV–vis) in microbial decontamination of ricotta artificially inoculated with Pseudomonas fluorescens. Cheese samples were stored at 4 °C, and microbiological and sensory analyses were performed for 9 days. From the microbiological point of view, control samples became unacceptable after less than 5 days, whereas ricotta treated by both UV-C and NUV–vis light remained acceptable for more than 6 days. Similar effects of UV-C and NUV–vis light were also recorded in terms of sensory quality. The shelf life of the samples subjected to the treatments was thus extended by 50%, suggesting the potential application of UV-C and NUV–vis light for cheese decontamination.