Hardware Platform to Detect Fat Percent in Milk Using a Lipase Immobilized PMMA-Coated Sensor

In this paper, a novel sensor, coated with lipase and polymethyl methacrylate, is proposed to detect the fat content of milk. Phase angle of the sensor impedance is changed with the milk samples of a different fat percent. The change of the phase angle is due to the hydrolysis of triglycerides, which are the key element of the milk fat. Hydrolysis process is catalyzed by the presence of external lipase, which is immobilized on the sensor surface. The sensitivity of the sensor is experimentally found as 0.5°/% fat. Milk fat is varied from 1.5% to 20%. A rechargeable battery operated hand-held instrument is proposed, which gives the output as low-fat milk (LFM), high-fat milk (HFM), or very high-fat milk (VHFM) according to the fat percentage of the milk. A study is carried out for power consumption by the instrument. Error analysis, specifications, and performance of the proposed instrument are also studied.