Aplicações da colorimetria por imagens digitais para identificação de fraudes no leite

Abstract

Milk is part of a group of foods of great nutritional value, being a source of protein, vitamins, and minerals. Due to these characteristics it is widely consumed, highlighting its commercial value. Considering the advances in knowledge about the effects that food has on human health, consumer demands for higher quality and healthier products have raised the level of quality control by producers, industries and inspection agencies. Milk, due to its characteristics, is one of the foods most susceptible to fraud. Numerous analytical methodologies have been developed to monitor and control its quality, checking for adulteration. The quality standards must be strictly controlled to ensure a healthy food that does not cause harm to consumers' health. The Normative Instruction N°. 68, of December 12, 2006, contains the official physical-chemical analytical methods for milk control. However, as new adulteration techniques have emerged, new methods for the detection of adulterants have been developed, demonstrating a high potential for determining the quality and/or authenticity of milk. Thus, the alternative developed in this work, which is simple to use and low cost, and which has shown great potential for monitoring possible frauds, is colorimetry by digital imaging. This was based on the use of smartphones to collect images of colorimetric reactions, which were processed to obtain information about the values of the RGB color space (red, blue and green), from which it was possible to perform the quantification of the analyzed substance. Interfering conditions were optimized, and analysis parameters were successfully established and the method was applicable, obtaining validated quantitative character by analyzing milk samples in different concentrations of sodium hypochlorite.