Abstract The açaí is a popular Brazilian fruit, however, already part of the world's healthy eating habits owing to its antioxidant properties. The study aimed to determine the effect of solvent in extracting phenolic compounds with antioxidant potential in açaí juçara (Euterpe edulis Mart.) using a Completely Randomized Design (CRD). The phenolic compound profile was quantified by High-Performance Liquid Chromatography (HPLC), and the data set was analyzed by Principal Component Analysis (PCA). The PCA was applied to evidence the relationships between the concentration of phenolic compounds and the solvents. Furthermore, the antioxidant activity was also determined by 2,2’-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Ferric Reducing Antioxidant Power (FRAP) methods. The solvent ethanol: water 70% was more efficient in extracting phenolic compounds with high antioxidant activity. In this extract, salicylic acid was found in high concentrations as well as catechin, epicatechin, and coumaric acid. Based on a consensus that phenolic compounds are associated with the most powerful antioxidant activities of fruits, the “açaí juçara” from the Atlantic Forest is a potential source of polyphenols. They could be used as natural antioxidants for application in the food and pharmaceutical industry in order to substitute the synthetic antioxidants.
Resumo O açaí é uma fruta popular brasileira, porém já faz parte dos hábitos alimentares saudáveis da população mundial, devido às suas propriedades antioxidantes. O objetivo deste estudo foi determinar o efeito do solvente na extração de compostos fenólicos com potencial antioxidante em açaí juçara (Euterpe edulis Mart.), utilizando um Delineamento Inteiramente Casualizado (DIC). O perfil dos compostos fenólicos foi quantificado por Cromatografia Líquida de Alta Eficiência (CLAE) e o conjunto de dados foi analisado por Análise de Componentes Principais (PCA). O PCA foi aplicado para evidenciar as relações entre a concentração de compostos fenólicos e os solventes. Além disso, a atividade antioxidante também foi determinada pelos métodos DPPH, ABTS e FRAP. O solvente etanol:água a 70% foi mais eficiente na extração de compostos fenólicos com alta atividade antioxidante. Neste extrato, o ácido salicílico foi encontrado em alta concentração, além de catequina, epicatequina e ácido cumárico. Com base no consenso de que os compostos fenólicos são os principais compostos relacionados à atividade antioxidante das frutas, o açaí juçara da Mata Atlântica é uma fonte potencial de compostos fenólicos e poderia ser usado como antioxidante natural para aplicação nas indústrias alimentícia e farmacêutica, em substituição aos antioxidantes sintéticos.
Abstract Due mainly to the taste and appearance, the strawberry stands out in relation to the other fruits. and for the presence of antioxidant compounds. However, little attention has been devoted to the impact of abiotic stresses on the quality of strawberry and its agronomic performance. In the present study, we evaluated the effect of two levels of DS (L1 - 70% and L2 - 50% of crop evapotranspiration) on the quality of strawberry fruit and on some agronomic and physiological variables. There was a dose-dependent reduction in the evaluated agronomic variables in the DS plants, and the content of some minerals in the fruit and leaves was modified. The activities of the oxidative enzymes were higher in the fruit of L2 treatment, and the content of sucrose, reduced sugars, phenolic compounds and the total antioxidant activity were increased in the fruit from L2 treatment; while those of anthocyanins and L-ascorbic acid were reduced in L1 and L2 treatments, respectively. The phenylalanine ammonia lyase gene was upregulated and other genes related to phenylpropanoid and ascorbate pathways were downregulated in the fruit of stressed plants. Thus, our results indicate that DS seems to be a promising strategy to improve the content of antioxidant compounds and sugars.