An automated system for impedance measurements in milk

Measurement of milk quality is important for commercial food safety and in the dairy processing industry. Several techniques have been investigated before, and measurements range from impedance detection time (for shelf-life prediction just after pasteurization) and conductivity (mostly for mastitis detection) to pH and capacitance. Most techniques use invasive probes, for which a good reference in milk is not yet available. This article discusses the design and results of an automated measurement system used to characterize impedance probes for bacterial content measurement in milk. With a reliable, repeatable measurement system, probe characterization and calibration is improved, which leads to faster and more accurate measurements of bacterial content and remaining shelf-life.