Effect of UVC Irradiation Using Pre- and Post-Drying on Quality of Dried Chili

Authors

  • P. Pianpumepong Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand
  • N. Prangpru Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand
  • P. Jannok Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand
  • J. Suntudprom Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand
  • W. Meeklangsan Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand
  • N. Sukthang Department of Food and Postharvest Innovation Engineering, Faculty of Engineering and Technology, Rajamangala University of Technology, Nakhonratchasima, 30000, Thailand

DOI:

https://doi.org/10.18502/jfqhc.13.2.22139

Keywords:

Capsicum, Ultraviolet Rays, Food Quality

Abstract

Background: Ultraviolet C (UVC) irradiation has been recognized as a non-thermal technology application in pre- and post-harvest agricultural work, since it is chemical- free and helps to reduce microorganisms and detoxify Aflatoxin (AF). Therefore, this study aimed to apply the UVC light before (pre-) and after (post-) sunlight drying in red chili and to investigate its qualities, yeast and mold growth, and AF level in dried red chili during storage at ambient temperature.

 

Methods: Red chilis were subjected to UVC irradiation at 5 min, 10 min, and 20 min pre- (UVC-Sun) or post-sunlight (Sun-UVC) drying. The physicochemical properties including Moisture Content (MC), Water Activity (Aw), surface color, pH, yeast and mold counts, and AF levels of dried chili, were investigated during storage. Data were analyzed using ANOVA, IBM software (SPSS version 23).

 

Results: MC and Aw tended to increase across all treatments during storage. UVC irradiation affected the surface color of chili, as UVC treatments tended to lower L* and a* values more than the control treatment (Sun). Sun and Sun-UVC treatments had significantly lower pH values compared to UVC-Sun treatments. Notably, UVC irradiation prior to sunlight drying was observed to be a superior method for reducing yeast and mold amounts and AF levels. In contrast, sunlight drying treatment resulted in higher yeast and mold amounts and AF levels. Therefore, using UVC irradiation prior to sunlight drying was more effective in these respects. This greater effectiveness may be attributed to the relatively smooth surface of chili, which enhances UVC light reflection and uniform exposure.

Conclusion: UVC irradiation and sunlight drying incorporation are recommended. Future studies should explore optimal exposure times and intensities to maximize safety and efficacy.

Published

2026-07-28

Issue

Volume (13) issue (2)

Section

Articles