Application of piezoelectric sensors with polycomposite coatings for assessing milk quality indicators.

Milk is an important and necessary food product for reducing morbidity in the human body. There are numerous falsifications of milk and dairy products in this regard. At the same time, one of the most time-consuming indicators of raw milk is microbiological parameters. The purpose of this research is to study the gas phase over raw milk samples using piezoelectric sensors with polycomposite coatings to assess its physicochemical and microbiological parameters. The sorption of volatile compounds onto the coatings based on chitosan, micellar casein concentrate, and amorphous silicon oxide in impact with polymeric sorbents was studied. This array was employed to analyse the gas phase over raw milk samples. It has been evaluated physicochemical indicators of milk (content of fat, protein, solid substances; acidity) and microbiological indicators (total microbial count; the presence of mould, yeasts, pathogenic microorganisms). The influence of several factors on the composition of volatile compounds in milk was evaluated using the output data of sensors. There are injector and frontal mode of input gas phase into the detection cell, the processing of milk samples by ultrasound and microwave radiation, the introduction of glucose and peroxide additives into samples. It has been established statistically significant correlations between the sensor output data and the physicochemical or microbiological parameters of raw milk samples. The regression models were constructed employing chemometrics techniques to predict the quality indicators of milk based on the output data of piezoelectric sensors with composite coatings, with an error comparable to that of standard methods.