Impact Of Plasma Bubbling On Cow Milk: Microbial Reduction And Improvement Of Milk Quality

Abstract

Raw milk has high nutritive value and is used as an important dietary supplement for humans. But, microbial contamination in milk has been a problem for era, while existing thermal technology often deteriorates the quality of milk and its valuable ingredients. Again, consumer demand for least processing technology without degradation of the product quality forced the scientist to develop novel methods relevant to the application of non-thermal technology which does not create any detrimental effect to the composition of milk are now being under scrutiny. One of the novel methods is plasma bubbling technique and is not yet examined for liquid foods like milk. In the present study, the plasma bubbling system was established for the decontamination of raw cow milk. The plasma bubbling was generated at voltage of 160V, for 5, 10 and 15 minutes (min) and was evaluated for microbial reduction at an air flow rate of 5 and 10 Litre/hour (L/h). It accounted for a maximum 1.33 log reduction for coliforms at 160V, flow rate of air was 10 L/h, for a 100mL of milk sample with 15 min exposure time, while for yeast the log reduction was 1.40. The plasma bubbled milk was analysed for its quality evaluation such as pH, acidity, colour and lactose content of milk. The value of pH was found to be 6.77 at 160V, 10L/h, 15 min and 100mL of sample volume while the control value of pH was 6.60. The findings from this study revealed that the atmospheric plasma bubbling system could be used for the pasteurisation of raw cow milk by reducing the microbial load without compromising milk quality. This work on novel atmospheric plasma bubbling is an initiative for the pasteurization of raw cow milk, which could have a potential impact on the food industry in future.