Bioimpedance sensor to detect water content in milk based on van Der Pauw method

Abstract

Milk fraud poses serious problems for the dairy industry and consumers' health. The main aim of this study was to reveal the effect of water added to milk by measuring its electrical impedance spectrum. The required sensor was designed based on the van der Pauw method to measure the electrical conductivity of milk at the frequency band of 10 Hz to 5 MHz. The bioimpedance spectrum of the milk of five different cows showed that the electrical impedance spectrum has a high potential for detecting water added to the milk (P < 0.01). The area under the Nyquist curve was introduced as a suitable index to detect water-added milk. In addition, the characteristic frequency of the bioimpedance spectrum was used as an important index to differentiate water-added milk from waterless milk. An electrical model was introduced to interpret the amount of water added to the milk using the characteristic frequency. Results showed that it is possible to detect raw milk from boiled milk by measuring its electrical impedance.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Сравнительная Оценка Спектральных Люминесцентных Характеристик Молока И Молочных Продуктов

“…The results obtained can be applied to create express control methods for processing and storing milk and dairy products. (Biçer & Sönmez, 2022) и другие методы Ashoorirad et al, 2021;Мельденберг и др., 2020). Хотя эти общепринятые методы точны и надежны, они разрушительны, отнимают значи тельное время, не всегда дешевы и экологически безопасны и могут использоваться только в лабо раторных условиях.…”

A Review of Milk Frauds and Adulterations from a Technological Perspective

“…Utilizing a lactometer or another traditional technique, the specific gravity is measured. These strategies fall short, though, if the weight after the adulteration is maintained at the same level [81][82][83]. Over time, many methods have been used to determine this type of adulteration, such as high performance liquid chromatography (HPLC), capillary electrophoresis, Fourier transform infrared spectroscopy (FTIR), and methods for determining the cryoscopic point.…”

“…Even if these techniques work, they are expensive, time-consuming, and require high-purity chemicals and expensive equipment, which leads to higher prices and slower outcomes. [81]. Other methods studied were spectroscopic methods based on electrical impedance, which, in addition to adding water, are able to detect even fomaldehyde, hydrogen peroxide, and sodium hydroxide.…”

“…The study's findings demonstrated that milk impedance spectra can be utilized as a low-cost, reliable, and accessible method to regulate milk quality in the dairy industry. This method is suited for identifying changes in milk [81]. Dave et al investigated a non-contact technique for using the apparatus with the milk sample, retaining its consistency and quality, and making it reusable for another test.…”