Extração de compostos fenólicos do resíduo do processamento do fruto goiaba serrana (acca sellowiana)

Abstract

Biorefinery has been boosting sustainable initiatives for the use of waste from the processing of fruits in several applications, one of them being the obtainment of bioactive compounds. The interest on these compounds focuses on their antioxidant, anti-inflammatory and anti-carcinogenic properties. The feijoa (Acca sellowiana), a tree native to the Brazilian Southern Plateau and northeast of Uruguay, is a fruit tree from the Myrtaceae family with great economic potential and is considered to be rich in bioactive compounds. Considering that, the objective of this study was to examine the phenolic composition and the antioxidant capacity of the waste from a sample of goiabeira-serrana by an experimental plan seeking to analyze the extraction conditions through ultrasound. The fruits were processed into pulp and later dried out in a heating chamber with the air circulation at 50ºC. They were then grinded with the help of a mortar and pestle and sifted through a 40 mesh. The obtained powder went through an extraction process by indirect ultrasound with the use of an ethanolic solvent with a solid/liquidratio of 40 mg.m L-1. The time of extraction was observed alongside the variables in temperature (ºC) and ethanol concentration (%, m/m) with the aid of the experimental planning technique. The obtained extracts were analyzed with respect to total phenolic content (TPC) and the total antioxidant capacity (TAC) through the Folin-Ciocalteau and DPPH methods, respectively. The time of extraction was found through kinetics and was observed to be of 50 minutes of permanence in the ultrasound bath. The extracts had great conversion numbers, reaching concentrations of CFT between 54,48 to 88,58 mg GA/g for the dry sample and concentrations of TAC between 337,06 a 426,58 μmol TE/g for the dry sample. For both TPC and TAC, the ethanol concentration and temperature showed a significant difference (p>0,05). The results show to be positive in the utilization of waste for the extraction of bioactive compounds.