Use of chitosan films to remove bordeaux s food coloring with quantification by digital image analysis

Bordeaux S is a food dye still allowed in Brazil, being present in soft drinks, gelatins, chewing gums, candies and many other industrialized foodstuffs. Because of its carcinogenic potential, it is forbidden to be added to food in Japan, in the USA and in most of the European Union. Many studies related to the employment of digital images analysis to food quality control have been published in recent years mainly due to its low costs of implementation. Nevertheless, one of the few drawbacks of applying this technique is its poor sensitivity, which can be significantly improved by employing solid substrates, such as chitosan films. In this work, chitosan sorbent films were synthesized, characterized and used to retain Bordeaux S present in gelatin samples, followed by recording the films' images and quantifying the analyte by digital images analysis. The proposed method was able to extract the analyte and eliminate interferences present in the matrixes in a single step. LOD of 20 mu g L-1 and LOQ of 74 mu g L-1 were obtained, allowing adequate quantification when considering the recommendations of the Brazilian Health Regulatory Agency (ANVISA).