Effects of Ultraviolet Radiation and Heat Treatment on the Inactivation of Clostridium sporogenes Endospores in Honey

ABSTRACT

Honey is a complex food matrix, rich in bioactive compounds and widely valued commercially. Despite its inherent stability, microbiological safety can be compromised by the presence of resistant bacterial structures, such as endospores, which are capable of surviving adverse conditions and conventional processing methods. Emerging technologies, including ultraviolet (UV) radiation, have been investigated as alternatives to improve microbiological control without compromising product quality. Therefore, the objective of this study was to evaluate the effectiveness of ultraviolet C radiation (UV‐C) alone and in combination with either ultraviolet B radiation (UV‐C + UV‐B) or heat treatment at 60°C for 15 min (HT + UV‐C) in the inactivation of Clostridium sporogenes endospores in laranjeira ( Citrus sinensis ) and silvestre honey. Additionally, the effects of these treatments on the physicochemical and rheological properties of honey were assessed. Honey samples were inoculated with standardized endospore suspensions (10 ⁵  CFU/mL) and subjected to the specified treatments. The results demonstrated a significant reduction in vegetative cells across all treatments, but no significant reduction in endospores, highlighting their high resistance. Physicochemical analyses indicated decreases in water activity and moisture, increases in soluble solids and viscosity, and no significant changes in pH. Hydroxymethylfurfural contents remained within acceptable standards. All samples exhibited Newtonian rheological behavior. UV‐C treatments, alone or combined with heat, effectively reduced vegetative cells while preserving honey quality. However, the limited inactivation of endospores indicates the need for additional strategies to ensure greater microbiological safety.