Bee pollen is an agglomerate of pollen grains from various botanical sources, which are collected by the bees and mixed with nectar and secretion from the hypopharyngeal glands such as β-glycosidase enzymes. Bee pollen has a complex chemical composition constituted of carbohydrates, proteins, aminoacids, vitamins and minerals, and is considered a good nutritional source, beneficial to health, particularly because of the presence of phenolic compounds with antioxidant activity. Therefore, the aim of this study was to assess the nutritional composition and antioxidant activity of the bee pollen produced in the Southern region of Brazil. The content of humidity, water activity, protein, total sugars, reducing sugars, crude fiber, lipids and minerals, as well as the content of total phenolic compounds, flavonoids, and antioxidant activity by the DPPH free radical scavenging method (2,2 diphenyl-1-picryl-hydrazyl) were determined. The mean contents of humidity, protein and reducing sugars were 4.19, 20.47 and 48%, respectively, and the predominant minerals were phosphorus, potassium, calcium and magnesium. The contents of phenolic compounds and total flavonoids were 30.46 ± 8.22 mg of GAE.g-1 pollen and 8.92 ± 5.5 mg of quercetin.g-1 pollen, respectively. High scavenging activities were found for the free radical DPPH, with EC 50 (minimum concentration required for the antioxidant to reduce the initial concentration of the DPPH by 50%) values that ranged from 810 to 4690 µg.mL-1. The bee pollen of Santa Catarina showed high antioxidant activity probably due to the high content of phenolic compounds present in pollen.

The aim of this study was to determine the antioxidant activity, phenolic content and antibacterial activity of pollen extracts obtained with different concentrations of ethanol. Each extraction condition (ethanol solutions from 40 to 90%) had a different effect in the phenolic compounds content. Although, the pollen extract obtained at 60, 70 and 80% of ethanol showed relatively higher levels of phenolic compounds (>10 mg/g) and did not present statistical significant difference between the extraction conditions. The amount of total phenolics ranged from 3.6 to 8.1 and 6.6 to 10.9 mg GAE/g for Alagoas state and Parana state pollen, respectively. The higher value for antioxidant activity index was 83.30% for the pollen from Alagoas state and 81.15 % for Parana state pollen. The highest degree of antioxidant activity was found in the extraction at 60% of ethanol solution for Parana state pollen, which also showed the highest concentration of polyphenol compounds. Staphylococcus aureus was inhibited by the ethanolic extract of Alagoas state pollen in all the concentrations of solvent, except the ethanolic extract of pollen at 90%. The extract at 60% of ethanol solution (Parana sample) inhibited Bacillus subtilis, Pseudomonas aeruginosa and Klebsiella sp.Index terms: Pollen, antioxidant, antibacterial activity. RESUMOObjetivou-se, neste estudo determinar compostos fenólicos, a atividade antioxidante a antibacteriana dos extratos etanólicos de pólen, obtidos com diferentes concentrações de etanol. As diferentes condições de extração (etanol de 40 a 90%) apresentaram diferentes efeitos no conteúdo dos compostos fenólicos extraídos. Os extratos de pólen obtidos com etanol a 60, 70 e 80% apresentaram maiores níveis de compostos fenólicos (>10 mg/g) e não apresentaram diferenças estatísticas entre essas condições de extração. A quantidade de compostos fenólicos nos extratos de pólen variou de 3.6 a 8.1 e 6.6 a 11 mg de equivalente em ácido gálico por g de pólen (GAE), para os estados de Alagoas e Paraná, respectivamente. Os maiores índices de atividade antioxidante para o pólen do estado de Alagoas foi de 83.30% e 81.15 % para o pólen do estado do Paraná. O pólen do estado do Paraná extraído com etanol a 60%, apresentou o maior índice de atividade antioxidante e também a maior concentração de compostos fenólicos. A bactéria Staphylococcus aureus foi inibida pelo extrato etanólico do pólen de Alagoas, em todas as concentrações, exceto no extrato etanólico a 90%. O extrato etanólico a 60%, no pólen do Paraná, inibiu Bacillus subtilis, Pseudomonas aeruginosa e Klebsiella sp.Termos para indexação: Pólen apícola, atividade antioxidante e antibacteriana.

The recovery of phenolic compounds of Eugenia pyriformis using different solvents was investigated in this study. The compounds were identified and quantified by reverse-phase high-performance liquid chromatography coupled with ultraviolet-visible diode-array detector (RP-HPLC-DAD/UV-vis). Absolute methanol was the most effective extraction agent of phenolic acids and flavonols (588.31 mg/Kg) from Eugenia pyriformis, although similar results (p ≤ 0.05) were observed using methanol/water (1:1 ratio). Our results clearly showed that higher contents of phenolic compounds were not obtained either with the most or the least polar solvents used. Several phenolic compounds were identified in the samples whereas gallic acid and quercetin were the major compounds recovered.

Recebido em 6/9/07; aceito em 24/4/08; publicado na web em 19/9/08 SCREENING OF THE ANTIOXIDANT POTENTIAL OF BEE POLLEN PRODUCED IN THE SOUTHERN REGION OF BRAZIL. The contents of total phenolics, flavonoids, and antioxidant activity of bee pollen ethanolic extract were determined and compared to those of commercial antioxidants. Bee pollen extract from the state of Rio Grande do Sul presented antioxidant activity statistically equal to that of α-tocopherol and higher than those of BHT and BHA. A statistically significant correlation was observed between the antioxidant activity and the total phenolics and total flavonoids contents of bee pollen extracts. HPLC technique made the identification of high contents of rutin and myricetin possible, which may partially explain the high antioxidant activity of Brazilian bee pollen.Keywords: antioxidant activity; bee pollen; HPLC. introduçãoO pólen apícola é um aglomerado de pólen de flores de várias fontes vegetais, os quais são coletados pelas abelhas e misturados com néctar e secreções das glândulas hipofaringeanas, como as enzimas α e ß-glicosidase.1 O pólen contém nutrientes como carboidratos, proteínas, aminoácidos, lipídeos, vitaminas e minerais, além de carotenóides, flavonóides e fitosteróis 1,2 sendo o motivo da sua utilização como alimento alternativo e/ou suplemento alimentar. 3,4 O pólen, a própolis e o mel têm recentemente recebido atenção especial entre os pesquisadores de todo o mundo, devido principalmente as suas propriedades biológicas, como atividade antibacteriana, 5,6 antifúngica, 7 antiinflamatória, 8-10 anticariogênica, 11,12 e imunomodulatória.13 O extrato de pólen (Cernilton ® ) tem sido utilizado no tratamento de alguns casos de prostatite benigna 14,15 e redução da sensibilidade oral em crianças que têm alergia a pólen. 16 Estudos têm demonstrado que a ação biológica do pólen é devida à presença de compostos fenólicos, tais como flavonóides, ácidos fenólicos e diterpenos fenólicos, que dentre outras propriedades biológicas possuem ação antioxidante. 9,[17][18][19] Os compostos sintéticos BHT (butil hidroxitolueno) e BHA (butil hidroxianisol) são antioxidantes efetivos e muito utilizados na indústria de alimentos, porém podem apresentar atividades mutagê-nicas.20 Neste sentido, a procura de agentes antioxidantes naturais tem recebido atenção especial por parte dos pesquisadores de todo mundo e da indústria alimentícia.A eficiência dos compostos polifenólicos como antioxidantes depende, em grande parte, de sua estrutura química, orientação relativa e do número de grupos hidroxila ligados ao anel aromático. 21,22 Entre os métodos que empregam radicais orgânicos na avaliação de seqüestradores de radicais livres, o método do DPPH (2,2 difenil-1-picril-hidrazil) tem sido extensivamente utilizado por vários autores, devido principalmente a sua simplicidade e rapidez. 23 Outro método bastante usado é o do clareamento do β-caroteno, que usa um modelo de substrato lipídico (ácido linoléico) em emulsão. 24,25 Portanto, este estudo teve como objetivo deter...

a b s t r a c tBee pollen, a honeybee product, offers an alternative approach to preventing the oxidative deterioration in meat products. The aim of this study was to evaluate antioxidant properties of lyophilized bee pollen extract (LBP), to determine the phenolic profile by liquid chromatography, and to evaluate the effect of LBP on the oxidative stability of pork meat sausage. The sausages were evaluated for lipid oxidation on the day of their production and every five days during 30 days of storage at 4 C by thiobarbituric acid reactive substances (TBARS). High concentrations of total phenolic compounds with antioxidant activity were detected in LBP (19.69 mg GAE/g: Gallic Acid Equivalent, EC 50 : 0.97 mg/mL respectively). The kaempferol was the majority compound (0.68 mg/g). The TBARS values increased over time with an average of 1.29 at 4.22 mg malonaldehyde/kg meat at the beginning and end of the experiment, respectively. Treatment with LBP showed lower (P < 0.05) TBARS values during any day of storage than the control and sodium erythorbate (SE) treatments. The LBP extract exhibited strong anti-oxidative effects in pork sausage, probably due to high antioxidant activity and the presence of the phenolic compounds in bee pollen; which has potential to be used in pork sausage.