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Recebido em 12/8/08; aceito em 4/2/09; publicado na web em 3/7/09 PHENOLIC COMPOSITION, ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF BRAZILIAN RED PROPOLIS. Propolis is a resinous hive product collected by honeybees from various plant sources. It has a complex chemical composition, constituted by various phenolic compounds. Extracts of increasing polarity (n-hexane, chloroform, and ethanol) were obtained from a sample of red propolis from the state of Alagoas. Assays were carried out for determination of contents of phenolics, along with antibacterial and antioxidant activities. The EEP, fractions and sub-fractions showed strong biological activities and were related with phenolic the content compounds contents. The sub-fractions were more bioactive than the EEP and fractions, demonstrating that the antioxidant and antibacterial activities are not a result of synergistic effect between the various chemical compounds in propolis.

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Phenolic composition and antioxidant activity of agroindustrial residuesRecebido para publicação 08.07. BV (20,94±0,46; 8,03±0,43)> BI (16,57±0,19; 4,41±0,01)> BG (3,41±0,09;1,88±0,06 PV (20.94±0.46; 8.03±0.43) >PI (16.57±0.19; 4.41±0.01)>PG (3.41±0.09; 1.88±0.06

Purification and bioassay-guided fractionation were employed to isolate proanthocyanidins with antioxidant activity from peanut skin (Arachis hypogaea Runner 886). The crude extract was prepared with acetone (60% v/v) and purified using chromatographic methods, including a semipreparative HPLC technique. As a result, two proanthocyanidins were isolated and identified using NMR, epicatechin-(2 β → O → 7, 4 β → 8)-catechin (proanthocyanidin A1) and epicatechin-(β → 2 O → 7, 4 β → 8)-epicatechin (proanthocyanidin A2). Despite the structural similarity, differences were observed in their antioxidant activity. Proanthocyanidin A1 proved to be more active, with EC50 value for DPPH radical scavenging of 18.25 μg/mL and reduction of Fe(3+)-TPTZ complex of 7.59 mmol/g, higher than that of synthetic antioxidant BHT. This compound evaluated by ABTS(+) was similar to that of natural quercetin. Therefore, peanut skin is an important source of bioactive compounds that may be used as a mild antioxidant for food preservation.

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The effectiveness of grape extracts as food ingredient has been tested in various systems. The objective of this study was to evaluate the efficiency of four concentrations of residues of the wine industry in delaying lipid oxidation in processed chicken meat stored under refrigeration. The development of oxidation during the 14-day storage was evaluated through the thiobarbituric acid reactive substances method (TBAS). The analyses of phenolic compounds and antioxidant activity were performed in grape residue extracts through DPPH (1,1-difenil-2-picrilidrazil) method, lipid peroxidation inhibition and Rancimat. The profile of polyphenols was determined using reversed-phase high-performance liquid chromatography. Isabel grape extract (IGE) and Niagara grape extract (NGE) showed significant content of phenolic compounds. NGE and IGE had high antioxidant activity. The addition of grape extracts significantly increased the oxidative stability of processed and cooked chicken meat during the storage time. The extracts from both grape varieties when applied in concentrations of 40 and 60 mg of GAE, presented results similar to that of Butyl hydroxy toluene (BHT).

The aim of this work was to study the chemical composition, botanical origin and the antioxidant activity of ethanolic extracts of bee pollen. The antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH.) scavenging method and b-carotenelinoleic assay. The pollen extracts were purified using a XAD2 resin and the amount of phenolic compounds and flavonoids were identified by reverse phase-high performance liquid chromatography (RP-HPLC) and gas chromatography-mass spectrometry (GC-MS) analyses. The phenolic content of bee pollen extracts before and after the resin were 38.6 and 17.8 mg/g of gallic acid equivalent in bee pollen, respectively. Two different flavonoids (rutin and myricetin) which can be accounted by the high antioxidant activity of bee pollen extracts were identified and quantified. The total antioxidant capacity measured by the DPPH. radical method increased significantly in bee pollen extracts purified with hydrophobic resin: 24.84-94.75% (Palmeira). All samples were considered heterofloral, which were composed by pollen from Myrtaceae eucalyptus, Asteraceae and Brassicaceae families, and among others.El objetivo de este trabajo fue estudiar la composicio´n quı´mica, el origen bota´nico y la actividad antioxidante de los extractos etano´licos de polen de abeja de Apis melıfera L. La actividad antioxidante fue medida por los me´todos de secuestro del radical 2,2-diphenyl-1-picrylhydrazylhydrate (DPPH . ) y por la oxidacio´n acoplada del beta-caroteno/a´cido linoleico. Los extractos etano´licos fueron purificados usa´ndose la resina XAD2 y la cantidad de compuestos feno´licos y flavonoides fueron identificados por el ana´lisis de RP-HPLC/UV-Vis y CG-MS. El contenido feno´lico de los extractos de polen de abeja antes y despue´s de la resina fueron 38,6 y 17,8 mg/g de GAE (equivalente en a´cido ga´lico) en el polen de abeja, respectivamente. Fueron identificados y cuantificados dos distintos flavonoides (rutina y miricetina), los cuales pueden explicar la alta actividad antioxidante de los extractos de polen de abeja. La capacidad antioxidante total medida por el me´todo del radical DPPH aumento´significativamente en los extractos purificados con la resina hidro´foba 24,84% para 94,75% (Palmeira/PR); 40,81% para 92,56% (Sa˜o Joaquim/SC); y 14,91% para 94,05% (Encruzilhada/RS). Todas las muestras fueron consideradas heteroflorales, las cuales eran compuestas por el polen de Myrtaceae eucalyptus y de las familias Asteraceae y Brassicaceae entre otras.