Ultraviolet-C treatment of spices and herbs: A critical review on microbial safety and quality retention.
Source: PubMed, NCBI / U.S. National Library of Medicine
Spices and herbs are major components of food systems worldwide due to their characteristic flavor, aroma and bioactive compounds. However, due to contamination during cultivation, handling or storage, they often host pathogenic bacteria, fungal spores and mycotoxins. Conventional decontamination methods such as steam treatment and chemical fumigation can reduce microbial loads but may adversely affect volatile compounds, pigments and antioxidant constituents. Consequently, research has shifted toward non-thermal and residue-free alternatives. Ultraviolet-C (UV-C) irradiation has emerged as a promising approach as it inactivates microorganisms through nucleic acid damage while minimizing thermal exposure. This review examines recent advances in UV-C applications for spices and herbs decontamination focusing on inactivation mechanisms, dose-matrix relationships, treatment kinetics, quality retention, reactor design and scale-up considerations. Studies show that UV-C treatments significantly reduce major foodborne pathogens such as Salmonella spp. and Escherichia coli while color, volatile compounds, antioxidant capacity and sensory attributes are largely preserved under selected treatment conditions. Nevertheless, industrial implementation remains constrained by shallow UV-C penetration, optical shielding, irregular particle geometry and non-uniform fluence distribution. Operational challenges include lamp aging, process monitoring and energy requirements, while equipment inve
Abstract
Spices and herbs are major components of food systems worldwide due to their characteristic flavor, aroma and bioactive compounds. However, due to contamination during cultivation, handling or storage, they often host pathogenic bacteria, fungal spores and mycotoxins. Conventional decontamination methods such as steam treatment and chemical fumigation can reduce microbial loads but may adversely affect volatile compounds, pigments and antioxidant constituents. Consequently, research has shifted toward non-thermal and residue-free alternatives. Ultraviolet-C (UV-C) irradiation has emerged as a promising approach as it inactivates microorganisms through nucleic acid damage while minimizing thermal exposure. This review examines recent advances in UV-C applications for spices and herbs decontamination focusing on inactivation mechanisms, dose-matrix relationships, treatment kinetics, quality retention, reactor design and scale-up considerations. Studies show that UV-C treatments significantly reduce major foodborne pathogens such as Salmonella spp. and Escherichia coli while color, volatile compounds, antioxidant capacity and sensory attributes are largely preserved under selected treatment conditions. Nevertheless, industrial implementation remains constrained by shallow UV-C penetration, optical shielding, irregular particle geometry and non-uniform fluence distribution. Operational challenges include lamp aging, process monitoring and energy requirements, while equipment investment, process validation and regulatory compliance influence commercial adoption. Emerging UV-C light emitting diode (LED) systems and mechanized reactors including fluidized-beds and rotary drums configurations may improve fluence uniformity, particle exposure and scalability. Overall, UV-C irradiation shows strong potential as a sustainable and scalable non-thermal technology for improving microbial safety in spices and herbs.