Proposition of Sample Preparation Procedure of Cassava Flour with Diluted Acid Using Mixture Design and Evaluation of Nutrient Profiles by Multivariate Data Analysis

In this study, we evaluated the efficiency of an extraction procedure with diluted acids using a digester block. The procedure was developed for the extraction of Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn in handmade cassava flour samples produced in the south and extreme southern regions of Bahia State, Brazil. A mixture design was used for the optimization of the proportions of the acid mixture used in the extraction procedure, and the optimized conditions were 3.0 mL of HNO3 (3.5 mol L-1) and 3.0 mL of HCl (3.5 mol L-1). In the south and extreme south regions were obtained twenty-two and twenty-nine cassava flour samples, respectively. The determination of the analytes was performed using an inductively coupled plasma optical emission spectrometry (ICP OES). Accuracy of the proposed procedure was evaluated from the analysis of the certified reference material (CRM) of rice flour (NIST 1568b) and the results obtained by the proposed method were statistically in agreement with the certified values. The concentration range of Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn found in the samples were compared with the values of recommended dairy intake (RDI), and we concluded that cassava flour is a good nutrient source. For the evaluation and interpretation of the data, multivariate analysis using principal components analysis (PCA) was used, and the results showed a separation between the samples of the south and extreme southern regions.