Method and apparatus for measuring quality of frying/cooking oil/fat

A device for monitoring change of quality of oils, comprising:

• a) a housing defining a chamber and an opening for access to the chamber, to be inserted into a cooking/frying vat containing cooking oil so that cooking oil enters said opening and substantially fills said chamber;
• b) a parallel plate capacitor located in the chamber which is adapted to provide an output;
• c) means located in said chamber for measuring transmittance of oils which is adapted to provide an output;
• d) means located in said chamber for measuring the temperature of oils which is adapted to provide an output;
• and
• e) a microprocessor connected to and adapted to store outputs from said capacitor, the transmittance measuring means and the temperature sensing means, said microprocessor calculates transmittance and capacitance values of said oil and compares the calculated transmittance value to a threshold transmittance value for said oil, and compares said calculated capacitance value to a reference capacitance value and relates changes to an increase in the amount of polar molecular constituents of the oil, and wherein said microprocessor utilizes the changes in the capacitance and transmittance values using a correlation algorithm to provide an output indicative of the quality of the oil.