Detection of adulteration in pasteurized milk using a non-targeted electrochemical methodology

Abstract

Milk is one of the most adulterated foods in the world. Water, urea, sucrose, or cheese whey are added to increase the volume of milk, cheat quality analysis methods, and achieve greater economic gains, which can affect the consumers’ health. Many analytical methodologies can be used to check for adulteration. Still, they focus on one or a few parameters and may not be disseminated in the production chain, due to their cost or complexity. Non-targeted methods, in turn, can be an alternative, as they determine the sample profile through chemometrics and allow discrimination between adulterated and unadulterated samples. This study proposes the use of the electrochemical methodology of differential pulse voltammetry and principal component analysis for the detection of adulterations of pasteurized milk with water, urea, and cheese whey. With the use of a homemade Cu/CuO electrode and differential pulse voltammetry, through changes in the electrical current at some applied potentials, it was possible to differentiate milk samples that were adulterated with reagent grade-urea, commercial urea, and cheese whey, from unadulterated samples, used as a reference. The inclusion of substances such as sucrose and sodium hypochlorite was also detected. The proposed methodology proved to be an efficient tool to assist the milk production chain in guaranteeing the quality of its products.