NEW METHODOLOGICAL ADAPTATIONS FOR TOTAL PHENOLIC COMPOUNDS QUANTIFICATION IN VEGETABLE MATRICES

Phenolic compounds naturally presented in fruits and vegetables have been associated with sensory and health promoting properties. As many diseases are associated with a rise generation of free radicals or reduction of antioxidant capacity, phenolics could be associated to anti-inflammatory, anti-tumor or anti-atherogenic activities. Those compounds may be extracted with organic solvents based on preferential dissolution of the components. Solvent selectivity brings promising results, considering its chemical properties, costs and toxicity. This work aimed to evaluate new methodological adaptations for total phenolics quantification of in plant matrices. Based on a completely randomized design, which presented as independent parameters, the type of solvent (ethanol, methanol, distilled water or acetone) and the spectrophotometer wavelength (725 nm or 760 nm), the response variable was the total phenolics quantification using the Folin-Ciocalteu. Anova was applied to analyze differences among wavelengths and solvents. There were no statistically significant differences between both wavelengths (P < 0.001). The test for homogeneity of variances showed that the water and methanol treatments presented high averages and variances, demonstrating heteroscedasticity. For normality test, all values approached the normal line and the assumption of data normality was achieved. Levene test presented normal distribution for solvents, with greater dispersion for water. The parameters analyzed in this study demonstrated that the wavelengths were efficient for the quantification of phenolic compounds and the solvents ethanol, methanol and acetone were the most appropriate for the extraction of these components in plant matrices.