The Effects of Diffraction Grating Density of Ultraviolet Light: Impacts on the Reduction of Mesophilic Bacteria in Processed Mozzarella Cheese

Abstract

Harmful pathogens, such as E.coli (a type of mesophilic bacteria) in processed cheese is a safety risk for the dairy industry. UV light is an effective tool that is used to sterilize dairy products, but is underexplored. Paired with diffraction grating, the intensity maxima of UV light is expected to increase, further reducing bacteria in cheese. Therefore, it was hypothesized that an increase in diffraction grating density results in an increase in mesophilic bacterial reduction in processed mozzarella cheese. The number of slits on the diffraction grating surface was increased to enhance the intensity maxima of UV light. Cheese samples were treated with UV light and then analyzed using the total viable count (TVC) method. The samples were then analyzed through the ANOVA (Analysis of Variance) test to measure the significance and reliability of the results. However, due to financial limitations and low slit range (50-600), insufficient evidence failed to reject the null. Despite failing to conclusively affirm or refute the hypothesis, collected data proved that UV light does have an effect, but the effect of diffraction grating density requires larger slit range, as the effects were potentially too small to produce visible effect. The study also suggests that the relationship between diffraction density and bacterial reduction may be weaker than previously assumed. Moreover, suitable equipment should be used in future experiments to ensure complete sterilization, homogenization, and use larger ranges of slits and dilution samples. Nonetheless, UV light should continue to be studied as a viable method of sterilization for pasteurized products, to ensure safety and prevent future foodborne outbreaks globally.