Simultaneous determination of vitamin B1 and B2 in complex cereal foods, by reverse phase isocratic HPLC-UV

Abstract

The evaluation of nutritional or functional components in grain products is an important feature for the industry, especially when recent regulations require a correct nutrition labelling, valid during all the shelf life of the product. For that reason, industry usually makes many efforts to develop simple and reliable analytical methods that can be easily applied in any quality control laboratories for routine analysis. Spectrofluorimetric analysis of thiamine and riboflavin are sensitive, but need specific equipment. A few HPLC-UV methods have been described but they are less sensitive, and present difficulties due to interfering compounds, particularly in complex food matrixes, as grains and derivatives.A combination of extraction and separation systems, that allows enough sensitivity, precision and accuracy for the analysis of vitamin B1 and B2 in complex cereal food products, by isocratic UV-HPLC, in a single wavelength simultaneous separation is presented, with the advantage of using low-cost equipment requirements, simple sample pre-treatment and short time. The achievement of this goal has involved the optimization of compatible extraction and measurement protocols for cereal matrices, comparing seven different separation conditions and six extraction/clarification matrices analysis. The selected method was comparatively validated and compared to reference AOAC spectrofluorimetric methods, providing comparable linearity and accuracy, with better specificity and precision parameters, as well as practical applicability.