Determining total solids and fat content of liquid whole egg products via measurement of electrical parameters based on the transformer properties

• A detecting system based on transformer properties was investigated.
• Liquid whole egg can respond to alternating magnetic flux.
• Electrical parameters and quality indices were linearly correlated.

A method for determining the total solids and fat content of liquid whole egg products based on the principle of transformer was developed. The electrical parameters (terminal voltage and λ value) in the secondary circuit, where the sample acted as the coil, were investigated under the action of alternating magnetic flux in the frequency range from 60 to 400 Hz. Findings indicated that subtle changes of quality indices could be detected by electrical parameters based on the transformer properties that relate to the amount of free ions in the samples. As the inductive voltage was fixed, terminal voltage was negatively correlated with quality indices of total solids and fat content. Therefore the decrement of impedance in the secondary circuit caused the increment of inductive current according to Ohm's law. Linear prediction models for the aforementioned quality indices based on these electrical parameters were also established. Judging from coefficients of determination (R2) and the root mean square error of prediction (RMSEP) of these models, the λ value was found to be a better predictor for quality indices of liquid whole egg products than terminal voltage. It is believed that this method has the potential to evaluate the quality of liquid food materials over a wider frequency and temperature range.