Caracterização parcial de enzimas oxidativas e quantificação de compostos fenólicos em frutos de três genótipos de cajazeira (Spondias mombin L.) nos estádios de maturação verde e maduro

Abstract

This study aimed to partially characterize the oxidative enzymes and quantify the phenolic compounds in fruits of three cultivars of yellow mombin (Spondias mombin L.) on maturation and mature green, installed in the Active Germplasm Bank of the Agricultural Research Company of Pernambuco - IPA. We used green and ripe fruits of genotypes IPA 2.1, IPA4.1 and IPA 6.1 with hard shell and, respectively, totally green and yellow coloring. After collection the fruits were transported, washed, sanitized and separated into: peel and pulp. Were determined soluble solids (SST), titratable acidity (ATT), pH and total phenolics. Then the crude extract was obtained using EDTA, CaCl2 and PEG 10,000 and the activity of peroxidase (POD) and polyphenoloxidase (PPO) were determined, as well as the quantification of soluble proteins. With the maturation of fruits were found to be a decrease in phenolic content and levels of ATT, an increased content of soluble solids and pH remained stable at various stages of pulp for genotype IPA 2.1 and IPA 4.1, while in There was a IPA 6.1 increase in pH during ripening. In caja fruit in both peel into the pulp in mature stage showed higher POD enzyme activity in the green maturity stage. Between average PPO activity in fruit peel and pulp of genotypes cajazeira in both maturity stages showed a significant difference, with higher activity in the bark, except for genotype IPA 4.1 green. Among the genotypes at maturity, which showed higher enzymatic activity for POD and PPO in the whole peel and pulp was IPA 6.1, except for genotype IPA 4.1 green. Through partial characterization of the pulp of genotype IPA 6.1 has been obtained the optimal pH and temperature of the enzymes POD and PPO, respectively, pH 7.0 and 50 ° C, pH 9.0 and 60 ° C. Both enzymes were stable at various pHs, from acidic and basic, keeping 100% of residual activity after 180 minutes. While the temperatures studied for the POD retained 100% of residual activity after 10 minutes and PPO showed relatively stable temperatures studied, maintaining 50% residual activity after 10 minutes at 90 ° C. The profile for POD and PPO enzyme obtained with the crude extract of the ripe pulp of genotype IPA 6.1 suggests the presence of isoforms.