Application of Piezoelectric Sensors with Polycomposite Coatings for Assessing Milk Quality Indicators

Abstract

Milk is an important and necessary food product for reducing morbidity in the human body. There are numerous misconceptions around milk and dairy products in this regard. At the same time, one of the most time-consuming indicators of raw milk comprises its microbiological parameters. The purpose of this research is to study the gas phase of raw milk samples, using piezoelectric sensors with polycomposite coatings, to predict its physicochemical or microbiological properties. The sorption of volatile compounds onto the coatings based on chitosan–micellar-casein concentrate with polymeric sorbents was studied. This array was employed to analyze the gas phase over raw milk samples. It evaluated the physicochemical indicators of milk (the contents of fat, protein, and solid substances; the acidity) and the microbiological indicators (the total microbial count; the presence of mold, yeasts, or pathogenic microorganisms). The influence of several factors on the composition of volatile compounds in milk was evaluated using the output data of the sensors. These are the injector or frontal mode of inputting the gas phase into the detection cell, the processing of milk samples via ultrasound and microwave radiation, and the introduction of glucose and hydrogen peroxide additives into samples. Statistically significant correlations have been established between the sensor output data and the physicochemical or microbiological indicators of raw milk samples. The regression model was constructed using partial least squares regression to predict the total microbial count of milk based on the output data of piezoelectric sensors with composite coatings, with an appropriate error.

Keywords

• chemical piezoelectric sensors
• polycomposite coating
• volatile compounds
• milk
• microbiological indicator