Characterization of volatile aroma compounds in cold plasma-treated milk

This work characterizes the oxidative changes that different plasma processing imparts on milk through volatile components analysis. Cow milk was subjected separately to two plasma treatments (plasma bubbling and low-pressure plasma) and in combination. Plasma altered the milk's volatile nature in both treatments; the combination amplified the volatiles produced. The maximum of 1.23 log10 microbial reduction was obtained when plasma treatments were combined together; however, the microbial count had less impact on volatile changes in the milk. Whereas, an increase in carbonyl (2.42 to 8.18 n mol/ml) and malondialdehyde (0.337 to 0.562 mg MDA/l) contents were highly correlated with the volatile changes in the milk. Overall, the type of plasma application into milk was observed to be an important parameter for increasing the efficiency of the processing; combining two plasma treatments produced a positive synergistic effect in microbial reduction; however, it increased the oxidation of milk. Novelty impact statement This study focuses on the investigation of the impact of different cold plasma application and its combination on milk. Though, there are many studies on combination of plasma with other treatments, to the best of our knowledge this is the first study to combine two plasma processing methods (plasma bubbling and low-pressure plasma). It helps in understanding which plasma application has more impact and also their synergistic effect on milk with the aid of volatile compound, microbial, and oxidative analysis.