Use of response surface methodology in optimization of phenolic compounds extraction from the shell of Hymenaea courbaril L. (Jatobá) fruits

Abstract The food and medicinal habits of Amazon people are rich in fruits considered as exotic or commercially underutilized, some of which generate a considerable amount of residue. The Hymenaea courbaril L. (Jatobá) fruit shell was submitted to a simultaneous extraction of total phenolic compounds, optimized by response surface methodology. Preliminary experiments, investigating sample-solvent ratio (g/mL), time (minutes) and extraction temperature (ºC), indicate the limits for experimental region design, which was monitored by rotational central composite design consisting of 19 runs. The experimental results fitted well to the second order polynomial model generated, which was able to significantly describe the observed variability for response variables. The optimized conditions were 60.6% ethanol, 64.18 ° C, 71.93 minutes and the model presented predicted values of 35.265 ± 2.22 mg gallic acid equivalent / g dry matter and 1.210 ± 0.16 mg rutin equivalent / g dry matter, for total phenolic compounds and total flavonoids, respectively. The experimental observed values, 33.234 ± 1.66 mg gallic acid equivalent / g dry mater and 1.216 ± 0.008 mg rutin equivalent / g dry matter, for total phenolic compounds and total flavonoids respectively, agreed with those predicted within a 95% confidence interval. These results confirm the predictive capacity and the adequacy of response surface methodology in optimizing simultaneous extraction of total phenolic compounds and total flavonoids from shell of jatobá fruits.