Development and evaluation of low-cost frequency based sensor for non-destructive detection of paneer spoilage

Food spoilage occurs due to the microbial and enzymatic activities which alter the composition of the product with their metabolites. Paneer, also called Indian cottage cheese, gets spoiled due to poor quality of milk, faulty production methods, unhygienic processing conditions, and poor refrigeration facilities. The spoilage has been detected conventionally by destructive sampling methods. This paper proposes a non-destructive method of detecting paneer spoilage using a Radio-Frequency (RF) based sensor. For generating a low frequency of 100 kHz, and passing it through the sample, a set up was made. Spoilage changed the composition of the medium which subsequently changed the dielectric constant of the medium. Therefore, frequency change was occurred in case of low frequency’s passage through the sample. Initially, prepared paneer samples were deliberately spoiled keeping at temperatures of 0, 10 and 250C up to 21 days. Then, the frequencies were measured every three days. The results showed that for the paneer kept at 250C, the frequency changed from 67±0.2 kHz on day 0 to 57±0.2 kHz on day 21.