UV-LED Irradiation of Black Pepper: A Non-Thermal Approach to Preserve Sensory Quality

The impact of ultraviolet light-emitting diode (UV-LED) irradiation on the chemical and sensory properties of black peppercorns is investigated in this study. Samples were treated with 280-, 300-, and 365-nm light, as well as at 280 + 300 nm. Total phenolic content, antioxidant activity, phenolic compounds, volatiles, piperine, fatty acids, and tocopherols were analysed, followed by a sensory analysis. Chemical and instrumental analyses revealed moderate changes (up to 40%) in phenolic compounds, volatiles, fatty acids, and tocopherols, with the combined wavelength treatment often resulting in a greater deterioration, and agitation being the main driver for quality degradation. However, sensory evaluation showed no significant differences in colour, smell, or flavour, indicating that organoleptic properties remained unaffected. The findings suggest that UV-LEDs offer a valuable and feasible alternative to conventional heat and water vapour treatments, avoiding humidity-related issues whilst preserving the product's organoleptic integrity. UV-LEDs demonstrated potential for non-thermal spice treatment with minimal sensory impact.