Innovative methodological approach using CIELab and dye screening for chemometric classification and HPLC for the confirmation of dyes in cassava flour: A contribution to product quality control

Abstract

A variety of methods for producing cassava flour exist, resulting in very heterogeneous products that exhibit various colours, textures, granulometries, and flavours. To improve its attractiveness to consumers, some producers dye cassava flour with turmeric or tartrazine; however, this practice is illegal in Brazil. In this study, cassava flour samples were collected and evaluated for possible adulteration by the addition of dyes. Flours were analysed by CIELab and dye screening (paper chromatography and the turmeric-identification method) and a classification tree was developed using these data. Positive results for curcuminoid pigments or tartrazine were confirmed by HPLC-DAD or HPLC-UV-Vis, respectively. The developed approach is an innovative alternative chemometric-analysis method that facilitates highly practical screening; adulterated cassava flour, a product of great human-food importance, can be identified using CIELab parameters.

Keywords: Chemometric analysis; Colour; Dye; Tartrazine; Turmeric.