Qualidade, compostos bioativos e atividade antioxidante durante a maturação de frutos de genótipos do umbuzeiro

Abstract

The umbu tree is an endemic fruit of the Brazilian semiarid, adapted to the characteristics of this region. This fruit tree starts to produce at low rainfall period. Its fruit is a drupe, with skin slightly hairy or smooth of green, is yellow when ripe, with a juicy pulp aqueous of sweet-sour taste. This fruit is extractively explored by farming families in the areas of occurrence. During the harvest period generates jobs and is source of income for families. Although it is very appreciated for fresh consumption and is known some characteristics of some umbu genotypes, plants occurring in some localities present features that require studies, especially during maturation. Thus, the aim of this study was to evaluate the quality of umbuzeiro harvested at different maturity stages, and the changes during the maturation on the bioactive compounds and antioxidant activity. Thus, this study was divided into two chapters. In the Chapter I, it was evaluated the quality of the fruits of umbu tree genotypes in different stages of maturation. This experiment was conducted with 16 genotypes of fruit umbu tree, 10 from the municipality of Casserengue, Paraíba state and 6 from the municipality Brejo da Madre de Deus, Pernanbuco state, Brazil. Evaluations were related to size, skin color, yields, and physicochemical characteristics. It was observed that the fruits harvested in Brejo da Madre de Deus presented more intense color of the skin when mature, larger size and fresh mass, exceeding by about 50% the average of the literature. From the 16 genotypes, 9 had lower acid content, and are appropriate for the fresh consumption when harvested at yellowish green and yellow maturity stages. In the Chapter II, it was evaluated the bioactive compounds and antioxidant activity of edible portions of umbu fruit genotypes harvested in different stages of maturation. For this experiment, fruits were peeled and analyzed separately for the pulp and peel in relation to bioactive compounds and antioxidant activity. It was observed that the phenolic compounds are the main responsible for the antioxidant activity, both in the pulp and in skin, along with flavonoids and ascorbic acid. The antioxidant activity of pulp and peel decreased with advancing maturity. The skin and pulp presented phytochemical contents and antioxidant activity that were, in an average, 5- and 15-fold higher than the pulp, respectively.