Please login first
Recovering antioxidant compounds from the juçara residue by a green approach
1 , 1 , 1 , 1 , 1 , * 2
1  National Institute of Technology
2  Laboratory of Organic and Inorganic Chemical Analysis, National Institute of Technology, Rio de Janeiro 20081-312, Brazil
Academic Editor: Lee Suan Chua

Abstract:

Juçara (Euterpe edulis) is a native palm from the Brazilian Atlantic Forest that produces phenolic-rich fruits. The fruits are used to obtain pulp, a functional ingredient employed in food preparations. However, for some purposes, juçara pulp needs to be refined, giving rise to a residue rich in antioxidant compounds and lipids. Thus, the objective of this work was to evaluate glycerol as green solvent in the microwave-assisted solid-liquid extraction of antioxidant compounds from juçara residue, as glycerol can be directly employed in food and cosmetic formulations because it is a substance generally recognized as safe. For that, an experimental design varying the glycerol concentration (0-100%), microwave exposure time (2-18 min) and temperature (53-187 °C) was adopted. The total phenolic compounds (TPC) and antioxidant capacity by DPPH were evaluated as responses. It was observed that the independent variables influenced the evaluated responses, mainly glycerol concentration and temperature (p<0.05). The TPC ranged from 1052 to 5329 mg GAE/100 g and antioxidant capacity from 29 to 191 µmol Trolox/g. The highest values were found at 187 °C, 50% glycerol for 10 min. All models were significant as the calculated F-values (117 and 38 for TPC and DPPH, respectively) were higher than the listed F-value (F9,7=3.68) at α=0.05. Also, it was not observed lack of fit for those responses. The R2 values of the models were higher than 0.98, accounting for, at least, 98% of data variability. Thus, using glycerol as a green solvent coupled with microwave-assisted extraction favored the recovery of antioxidant compounds from the juçara residue, presenting itself as a sustainable approach for adding value to the fruit production chain.

Keywords: Euterpe edulis; glycerol; microwave; phenolic compounds.
Top