UV-C Light Treatment to Extend the Shelf-Life of Paneer (Un-ripened Soft Cheese)

Aim: Application of UV-C light to reduce the post-processing surface contamination and to extend the shelf-life of paneer

Study Design: The study was aimed for 3×4 factorial design and the paneer samples were exposed to UV-C light for 60, 120 and 180 seconds and studied for its surface decontamination bymicrobiological studies and effect on sensory properties using 9-point hedonic scale after 3, 6 and 9, days of storage in a refrigerated conditions.

Place and Duration of Study: Karnataka Veterinary Animal and Fisheries Sciences University (KVAFSU), Dairy Science College, Mahagaon Cross, Kalaburagi, Karnataka, India

Methodology: A standard method was followed for the preparation of paneer. The paneer samples were treated with UV-C light in a UV chamber. Further, the samples were analysed for its Total Bacterial Count (TBC), Yeast and Moulds, and Coliform count, and sensory attributes such as flavour, colour and appearance, body and texture, and overall acceptability on a 9-point hedonic scale. The sensory evaluation of the sample was carried out by a panel of minimum 10 semi-trained judges who are well acquainted with the product features.

Results: The effect of varied exposure time of UV-C light and after storage days for a specific period was studied on the level of destruction of microbial-count and effect on the sensory characteristics. There was a significant (P=0.05) difference between the treated and non-treated samples in their microbial-count., and a log scale reduction in the bacterial and yeast and mould count on the surface by the effect of UV-C light was observed. The overall acceptability score for UV-C treated and non-treated sample was 8.36 and 8.10 at 0th day, and 7.02 and 5.65 after 9 days, respectively. Hence, the result was comparable to that of non-treated paneer.

Conclusion: The chemical-free and cost-effective UV-C treatment for surface decontamination of microorganisms could be a viable technique to extend the shelf-life of paneer.

Recommendation: Combination of other non-thermal techniques with UV-C light and with different packaging method could be studied to enhance the keeping quality.