Effect of milk film thickness on the efficiency of UVC radiated sterilization of raw cow’s milk

ABSTRACT

In this study, the effect of UV-C radiation at different milk thickness levels on the bacterial count of raw and pasteurized milk contaminated with Escherichia coli was investigated. A total of 27 samples were irradiated with different UV-C doses (1302.0, 33839.7, and 64,060.7 J/m²) and at different thicknesses (2, 4, and 6 mm). A quadratic model was developed to predict the bacterial count as a function of the UV-C dose and the thickness of the milk. The results showed that the bacterial count decreased exponentially with increasing UV-C dose and that the effect of the dose was more pronounced at lower thicknesses. The statistical analysis of the data revealed that the model was highly significant, with an adjusted R-squared of 0.981. Additionally, physical and chemical analyses were performed on the irradiated pasteurized and E. coli-contaminated milk and compared to the respective standard for pasteurized milk. The results showed that the quality and composition of the milk treated with UV-C were not affected. The results of this study indicate that UV-C radiation can be used as an effective method for reducing bacterial counts in milk while preserving the quality and composition of the milk.

KEYWORDS:

• UV-C radiation
• bacterial count
• milk
• Escherichia coli
• pasteurization

Disclosure statement

No potential conflict of interest was reported by the author(s).