Optimization of solvent mixtures for extraction from bark of Schinus terebinthifolius by a statistical mixture-design technique and development of a UV-Vis spectrophotometric method for analysis of total polyphenols in the extract

Abstract

A statistical mixture-design technique was used to study the effects of different solvents and their mixtures on the yield, total polyphenol content, and antioxidant capacity of the crude extracts from the bark of Schinus terebinthifolius Raddi (Anacardiaceae). The experimental results and their response-surface models showed that ternary mixtures with equal portions of all the three solvents (water, ethanol and acetone) were better than the binary mixtures in generating crude extracts with the highest yield (22.04 ± 0.48%), total polyphenol content (29.39 ± 0.39%), and antioxidant capacity (6.38 ± 0.21). An analytical method was developed and validated for the determination of total polyphenols in the extracts. Optimal conditions for the various parameters in this analytical method, namely, the time for the chromophoric reaction to stabilize, wavelength of the absorption maxima to be monitored, the reference standard and the concentration of sodium carbonate were determined to be 5 min, 780 nm, pyrogallol, and 14.06% w v -1 , respectively. UV-Vis spectrophotometric monitoring of the reaction under these conditions proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform.

Evaluation of the Folin-Ciocalteu Method and Quantification of Total Tannins in Stem Barks and Pods from Libidibia ferrea (Mart. ex Tul) L. P. Queiroz

“…In addition, the reaction depends on the amount of hydroxyls that are present in the aromatic rings of the polyphenols. This effect can be observed when different molecules are analyzed as markers, and thus an increase in the molar absorptivity value is shown in the following order: pyrogallol > catechin > gallic acid 30,31,45,46 . In this sense, the selection of the reference standard was based on the analytical responses of the different patterns to the Folin-Ciocalteu reaction and their respective molar absorption coefficients.…”

“…In regard to the Folin-Ciocalteu reaction, the presence of hydroxyl groups in the phenolic compounds is a determinant for the oxidation reactions and formation of the reaction product responsible for the coloration proportional to the concentration of the metabolite 30,39,45 . In addition, the reaction depends on the amount of hydroxyls that are present in the aromatic rings of the polyphenols.…”

Relative protection factor optimisation of natural antioxidants in biodiesel B100

“…Several authors have used this optimisation tool in various fields of science (Schamne et al, 2010;Borsato et al, 2014;DiCiaula et al, 2014). Currently, the mixture design has been used to optimise formulations, reduce costs and solve manufacturing problems (Cini et al, 2013).…”

Stem bark extracts of Endopleura uchi (Huber) Cuatrec: Inhibition of pancreatic lipase and antioxidant activity

“…In such cases, the extraction is facilitated by the presence of hydroxyl, carboxyl (Anokwuru et al, 2011) and polar and non-polar fragments of polyphenol molecules (Diciaula et al, 2014), which allow hydrogen bonding between them and the electronegative oxygen atoms of ethanol and acetone (Galanakis et al, 2013).…”