USE OF HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR DETECTING FRAUD IN CUPUAÇU PULP: A CHEMOMETRIC APPROACH

Cupuaçu pulp is the main derivative of the fruit of Theobroma grandiflorum and has unique flavor and aroma characteristics that enhance its value and distinction. Its production and commercialization involve stages and characteristics that can contribute to adulteration, which is a common practice in fruit derivatives. The most common adulterants in this type of product are water and solid reconstituents, such as sugar, starch, and other polysaccharides. In view of the above, the main objective of this study was to identify and quantify adulteration in cupuaçu pulp using high-performance liquid chromatography (HPLC) combined with chemometric techniques. For the development of the study, 66 pulps were produced from whole fruits. These were adulterated with a 10% (w/w) sucrose solution at concentrations of 15, 30, and 45% (w/v), totaling 264 samples analyzed. All samples were characterized by HPLC coupled to a refractive index detector, using an ion exchange column. To evaluate all the information contained in the chromatograms of each sample, the data were organized in a matrix with 264 columns by 3613 rows (retention time points). The Icoshift algorithm was used to align the chromatograms. The chemometric (statistical) analysis of the chromatographic data was performed using Principal Component Analysis (PCA), Partial Least Squares Regression Analysis (PLS), and Partial Least Squares Discriminant Analysis (PLS-DA). Sucrose, citric acid, glucose, and fructose were identified in all samples. As expected, the adulterated pulps showed an increase in sucrose concentration and dilution of the other constituents. In the PCA, there was a tendency for the original samples to cluster together and separate from the adulterated samples. For the PLS-DA models, excellent prediction results were obtained, with 100% accuracy in classifying authentic or adulterated samples. Regarding fraud quantification, the PLS model presented a correlation of 0.93 for the predicted and actual values, indicating an excellent fit. According to the results obtained, the use of HPLC associated with chemometrics proved to be efficient for verifying the authenticity of cupuaçu pulp.