Abstract: Background: Mastitis is one of dairy cattle's most economically relevant diseases globally, as it often results in bacterial milk contamination. Proteus vulgaris is cited as a pathogenic bacterium commonly identified in mastitic milk. It poses a significant health risk to consumers and decreases milk quality.
Objective: The purpose of this research project was to test the efficacy of High-Temperature Short-Time (HTST) and Low-Temperature Long-Time (LTLT) pasteurization methods in reducing the bacterial load of Proteus vulgaris in cow milk samples obtained from mastitic-infected cows.
Methods: Mastitic-infected milk was inoculated with Proteus vulgaris and pasteurized using HTST (72°C for 15 seconds) and LTLT (63°C for 30 minutes). The bacterial growth activity was measured immediately after pasteurization and after 72 hours of storage at 4°C; growth activity was measured at 4, 12, and 24-hour intervals.
Results: The growth activity of P. vulgaris was significantly reduced by both HTST and LTLT pasteurization procedures to 44.41% and 25.57%, respectively, during the 24-hour incubation period (P<0.001). Prior to storage and following the 72-hour storage, samples treated using the LTLT method exhibited significantly greater bacterial activity than the HTST-treated samples (44.41±14.35 vs 25.57±32.71, P<0.001, 41.28±20.39 vs 17.37±27.54, P<0.001).
Conclusions: The research project confirmed that LTLT and HTST pasteurization methods effectively reduced P. vulgaris growth activity in cow milk samples. However, HTST provided greater bacterial load reduction than LTLT. Regardless, pasteurization is an important food safety measure when processing mastitic milk.
