" />In 2025, Nuvonic secured an order to supply a UV system for sugar syrup disinfection for a global beverage brand. The use of UV has become an established part of thesugar syrup disinfection process dramatically reducing the cost, power consumption and maintenance requirements associated with traditional pasteurization as well as targeting heat resistant microorganisms unaffected by the heat treatment process.
Sugar syrup still presents challenges for the UV process, with low UV transmissivity (UVT) and variable viscosity it is difficult to type test the effectiveness of the process, leading bottlers to rely on recirculation through the UV system to achieve the required microbiological reduction.
Achieving strict microbiological targets for sugar syrup using a Single‑Pass UV Process for a Global Beverage Brand
- Single-pass UV Sugar Syrup Disinfection
- ≥3 log reduction of Alicyclobacillus and Aspergillus
- The design must achieve a careful balance between effective microbiological control and minimizing any potential sensory impact on the syrup.
The Design Challenge
Independent laboratory research into spoilage microorganisms in juices and beverages has guided users towards a UV dose of 90 mJ/cm² RED per log reduction for Alicyclobacillus (ACB) and Lactobacilli (LAB) post‑storage, with recirculation, as an effective solution. For this project the challenge was much higher, with the requirement to achieve ≥3‑log reduction of Alicyclobacillus accidoterrestis and Aspergillus niger at a 17.5 m³/h design flow rate, without recirculation.
Aspergillus niger (ATCC 32625) was identified as the most UV‑resistant target microorganism and therefore the critical performance benchmark. The UV Unit was designed to achieve the required pass criterion of ≥3‑log reduction for both microorganisms.
The Solution
The selected UV system was the Nuvonic PureLine S PH 0080, designed to deliver effective disinfection at low UVT conditions and incorporating medium pressure lamp technology which is unaffected by the wider fluid temperature range commonly associated with sugar syrup applications. The system was installed in late 2025, with performance testing completed in early 2026. Testing was conducted to define the operating limits of the UV system – considering both microbiological reduction and sensory performance.
Testing included single‑pass operation at flow rates up to 20m³/h. Additional testing at lower flow rates assessed the impact of UV treatment on the syrup’s taste, odour, and appearance. Sensory evaluations were also performed during recirculation to simulate mixing‑tank changeover while the UV system remained in operation.
Performance Highlights: Results That Matter
- Proven microbiological performance in single-pass operation
- Qualified operation over a range of production flow rates
- No impact on taste, odour, or appearance within defined limits
- The sugar syrup product meets its required quality standards
- Proven UV solution for consistent product and brand protection
Conclusion
The test results demonstrated that the required outlet microbiological parameters were consistently met at flow rates of up to 20 m³/h in a single-pass process. Single‑pass and recirculating sensory testing was successful over a range of lower flow rates and results confirmed the syrup could be recirculated through the UV system, allowing plenty of time for mixing-tank changeover, without affecting sensory performance.
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