A Continuous Flow UV-C Radiation and Ozone System for Yeast Reduction in Honey
Agastya Surya Visinanda (1), Aina Mardhiyah (1), Amanda Alya Kamilla (1), Mergy Gayatri (2), Dewanto Harjunowibowo (1*)

1) Department of Physics Education, Sebelas Maret University, Surakarta, Indonesia
2) National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, London, United Kingdom

Abstract

Honey is widely recognised for its nutritional benefits and inherent antimicrobial properties. However, due to its hygroscopic characteristics, it remains vulnerable to yeast contamination, particularly in humid conditions. This study evaluates a non-thermal preservation approach that combines UV-C radiation and ozone within a continuous flow system to inhibit yeast growth in honey. Two samples of local Klanceng (Trigona spp.) honey were examined: one serving as a control, and the other subjected to treatment with UV-C at 1.096 \pm 0.004 mW/cm^{2} and ozone at 10.3 \pm 0.3 ppm, each applied for 15 minutes, corresponding to total doses of 11.508 mJ/cm^{2} and 107.8 ppm \cdot s, respectively. The treated sample demonstrated a 48% reduction in yeast count. The \log reduction value reached 0.281, approaching the conventional 0.3 threshold commonly associated with a 50% microbial decline. This finding is particularly noteworthy given that the method avoids thermal degradation, thereby preserving the delicate qualities of honey. While the treatment did not completely eradicate yeast, it produced a measurable and meaningful impact. These results suggest that the combined use of UV-C and ozone may represent a promising, food-safe preservation technique. Further research exploring extended exposure durations, varied flow rates, and long-term effects would be valuable for the food industry to fully elucidate the potential of this approach.

Keywords: Continuous flow processing- honey- Non-thermal pasteurisation- UV-C and ozone treatment- Yeast

Topic: Medical Physics and Biophysics