University of Salerno: independent study tests the effectiveness of visible blue-violet light for microbiological control of raw meat

A new preprint study conducted by the University of Salerno tested the effectiveness of visible blue-violet light (400-420 nm, UV-free) on beef hamburgers during normal handling operations, simulating real conditions in professional kitchens and food processing facilities.

The most critical phase: after opening

The study focused on the most delicate moment: after package opening, when products are exposed to repeated handling, contact with work surfaces, and environmental contamination.

The results: fewer bacteria with blue-violet light

Samples exposed to blue–violet light were compared with samples under standard lighting, both at room temperature and under refrigeration.

The results showed consistently lower bacterial counts in illuminated samples, with:

slower bacterial growth at room temperature
greater microbiological stability under refrigeration
continuous control action, not a shock treatment

The observed effect works as a constant environmental safeguard, integrable into normal operations without interrupting workflow.

Effects on the product

In terms of quality, the study detected gradual and manageable changes:

moderate moisture loss
slight increase in firmness
minor color variations

All these effects depend primarily on temperature and exposure time, and are significantly reduced when working under refrigeration.

Conclusions

The data confirm that visible blue–violet light can function as a continuous sanitization tool, safe for operators and usable during normal activities, without the constraints typical of UV-C lamps.

The complete study document is available for download.

DOWNLOAD THE ARTICLE (PDF)

Source: Barba A.A., Lamberti G., “Improving the Microbiological Safety of Raw Meat Through Visible Blue–Violet Light Irradiation”, University of Salerno, open access preprint under CC BY 4.0 license, DOI: 10.20944/preprints202601.1932.v1

Exhibitor Data Sheet