Ultraviolet-C Treatment: A Non-Thermal Approach for Surface Decontamination of Peda (Traditional Indian Sweet)

Abstract

Background: Ultraviolet-C (UV-C) radiation is an emerging non-thermal food preservation technology that effectively inactivates a wide range of microorganisms while causing minimal changes to the sensory and nutritional quality of foods. In khoa-based sweets such as Peda, which are highly susceptible to post-processing surface contamination and spoilage, UV-C treatment offers a promising approach for enhancing microbial safety and extending shelf life. Aim: To study the effect of ultraviolet-C (UV-C) radiation on the surface decontamination of peda and to study its microbial properties and shelf-life extension. Study Design: Two-way ANOVA Place and Duration of Study: The study was conducted in the Department of Dairy Engineering, Dairy Science College, Mahagaon Corss, Kalaburagi, Karnataka, between July 2025 and February 2026. Methodology: UV-C light is a promising non-thermal technique in the food industry for food preservation and safety. UV-C light of 240-280 nm has a germicidal effect, offering an effective, non-thermal approach for decontaminating surfaces. Despite the recognized efficacy of UV-C radiation for various foods, its specific application and effectiveness for microbial decontamination and shelf-life extension of ‘Peda’, a unique heat-desiccated Indian dairy product, remain largely unexplored. This study therefore provides the first detailed assessment of UV-C treatment parameters and their impact on microbial load and initial quality attributes for Peda. Microbial analysis was performed on Peda samples exposed to UV-C light for 180, 240, and 300s, and the results were compared with those of untreated control samples. The samples were packed in low-density polyethylene (LDPE) pouches and stored for 15 days at 30°C, simulating typical ambient storage conditions for Peda in tropical climates to assess shelf-life. Results: A germicidal effect was noted, with the total bacterial count decreasing from 3.95 log cfu/g in the control sample to 3.25, 2.92, and 2.36 log cfu/g after 180, 240, and 300s, respectively. Similarly, yeast and mold counts decreased from 3.66 log cfu/g in the control sample to 3.28, 2.70, and 1.62 log cfu/g after 180, 240, and 300s, respectively. The coliform count was zero in all the samples. Moisture content decreased and FFA content increased, and sensory score decreased upon storage for 15 days. Conclusion: This technique is quick and easy to implement and has the potential to prevent surface post-process contamination of Peda.