Qualitative and quantitative multivariate strategies for determining paprika adulteration with SUDAN I and II dyes

Publication date: March 2019Source: Microchemical Journal, Volume 145Author(s): Cristina Márquez, Itziar Ruisánchez, M. Pilar CallaoAbstractTwo strategies based on multivariate qualitative and quantitative analysis are proposed for determining whether paprika samples are adulterated with Sudan I or II dyes. The samples were characterized by their UV–visible spectrum. Then, the following chemometric techniques were applied: principal component analysis (PCA) for the data exploration stage, partial least squares-discriminant analysis (PLS-DA) for the qualitative strategy and partial least squares (PLS) for the Sudan quantification strategy.Three classes were considered in the qualitative analysis: unadulterated, adulterated with Sudan I and adulterated with Sudan II. For the quantitative analysis, models were developed for each adulterant in a concentration range of 0–12 mg g−1, where 0 mg g−1 stands for the unadulterated samples.Both strategies gave satisfactory results. The multi-class PLS-DA model properly differentiate between the three types of studied samples: non-adulterated and adulterated with Sudan I and with Sudan II. Only samples at the lowest concentration (1 mg g−1) were wrongly detected as unadulterated. The PLS models were validated by setting the regression line of the model-predicted concentration versus the real concentration for the test set samples. The slope and intercept of each regression line were compared with those of the ideal...

Source: Microchemical Journal - November 28, 2018 Category: Chemistry Source Type: research