surface pasteurization or disinfection by ultraviolet irradiation A preservation by irradiation process in which microorganisms are reduced or eliminated on or in material by exposure to ultraviolet irradiation. LanguaL curation note: Used when sufficient ultraviolet radiation is applied to destroy most pathogenic and spoilage organisms present on the surface or to inhibit sprouting of stored agricultural produce and destroy storage pests. When followed by refrigeration, also index *preservation by CHILLING*. preservation by irradiation