UV-C Disinfection and Impact on the Quality of Black, White, Green, and Pink Peppercorns Using a Scalable Reactor

Abstract The spice industry faces significant challenges in ensuring the safety and quality of its products, mainly since they are commonly consumed raw. Whilst effective in inactivating pathogens, thermal treatments often degrade the sensory quality of spices, making them unfeasible. This study explores the potential of short wavelength ultraviolet (UV) disinfection as a non-thermal alternative, focusing on its disinfection efficacy and impact on the quality of black, white, green, and pink peppercorns from various geographical sources. A substantial reduction in Escherichia coli was demonstrated using an industrially scalable rotary reactor, with the highest reductions observed in green and black peppercorns. The use of the reactor proved to be more effective than a static treatment, highlighting the importance of uniform distribution of the UV light exposure. The results demonstrated that the antioxidant activity, total phenolic content, and piperine content remained unaltered following UV-C treatment in most of the samples. This finding indicates that the sensory characteristics of the peppers were not significantly altered, whilst food safety was enhanced. Nevertheless, additional research on sensory analysis is necessary to understand the impact on sensory perception and the potential of LED-based UV lamps as an effective and efficient method for ensuring food safety in the spice industry.