Percorrer por autor "De-Melo, Adriane A.M."
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- Antimicrobial activity of dehydrated bee-pollen produced in four Brasilian States against microorganisms with clinical importancePublication . Almeida-Muradian, Ligia Bicudo; De-Melo, Adriane A.M.; Pereira, Ana Paula; Estevinho, Leticia M.The objective of this study was to determine the antimicrobial activity of eight dehydrated bee pollen samples collected from April to July 2012 in four Brazilian States: Sergipe Bahia; Rio Grande do Sul and São Paulo.
- A diagnosis of the microbiological quality of dehydrated bee-pollen produced in BrazilPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Almeida-Muradian, Ligia BicudoBee-pollen is an apicultural product with potential for medical and nutritional applications; therefore, its microbiology quality should be monitored. In this context, the objective of this study was to diagnose the microbiological quality of 45 dehydrated bee-pollen samples collected from November 2011 to December 2013 in nine Brazilian States. All the samples were negative for sulphite-reducing Clostridium spores, Salmonella, coagulase-positive Staphylococcus and Escherichia coli, which are micro-organisms of public health concern. Total aerobic mesophilic micro-organism counts ranged from < 10 to 1·10 × 10 4 CFU g -1 , with psychrotroph counts ranging from < 10 to 1·12 × 10 3 CFU g -1 and total coliforms from < 10 to 2·80 × 10 3 CFU g -1 , while the values for yeasts and moulds were between < 10 to 7·67 × 10 3 CFU g -1 . According to the literature, the microbiota observed in this study were typical; however, it is important to consider that these micro-organisms may cause spoilage and diminish shelf life, reason by which quality control programs should be implemented. Significance and Impact of the Study: Contamination of bee-pollen can occur during production, collection and processing, but there are few studies of the microbiological quality of this product. Brazil is an important producer of dehydrated bee-pollen, therefore, a diagnosis of the microbiological status is important to ensure the safety of many consumers. Salmonella sp., genus Clostridium, coagulase-positive Staphylococcus, Escherichia coli and even some yeast species are micro-organisms of public health concern and their presence must be monitored. Furthermore, the determination of spoilage micro-organisms indicates whether the production and the processing practices carried out by beekeepers and warehouses were adequate. Significance and Impact of the Study: Contamination of bee-pollen can occur during production, collection and processing, but there are few studies of the microbiological quality of this product. Brazil is an important producer of dehydrated bee-pollen, therefore, a diagnosis of the microbiological status is important to ensure the safety of many consumers. Salmonella sp., genus Clostridium, coagulase-positive Staphylococcus, Escherichia coli and even some yeast species are micro-organisms of public health concern and their presence must be monitored. Furthermore, the determination of spoilage micro-organisms indicates whether the production and the processing practices carried out by beekeepers and warehouses were adequate.
- Efect of Gamma irradiation on the microbiological quality of dehydrated bee-pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Almeida-Muradian, Ligia BicudoThe objective of this study was to determinate some microbiological parameters of seven dehydrated bee-pollen collected from September to December of2012, in Brazil, before and after irradiation, in order to observe if the conservation process influenced the final microbiological load. All bee-pollen samples were collected in the same apiary and processed as usual; then one parcel of each one was gamma-irradiated to achieve dose of 5.0 kGy with a cobalt-60 source (by EMBRARAD/Empresa Brasileira de Radia~aes Ltda, Cotia, SAo Paulo, Brasil). The bee-pollen samples were analysed to enumerate aerobic mesophilic and psychotrophs bacteria, Staphylococcus aureus, total coliforms and yeasts and molds and to determine the presence or absent of sulphite-reducing Clostridium spores and Salmonella. Each sample ( 10 g) was homogenised and serial dilutions were inoculated on specific medium. Afterwards, incubations were performed depending on the microorganism (Estevinho et al., 2012). Results were expressed as colonyforming units per gram of dehydrated bee-pollen (CFU.g-1) for mesophilic, psychotrophs, Staphylococcus aureus, total coliforms and yeasts and molds or as presence or absent for sulphite-reducing Clostridium spores and Salmonella.
- Effect of processing conditions on characteristics of dehydrated bee-pollen and correlation between quality parametersPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Sattler, José Augusto Gasparotto; Souza, Bianca Rodrigues; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia BicudoThe aim of the present study was to compare the physical, chemical and biological parameters and the microbiological quality of bee-pollen samples treated with different dehydration processes and to correlate the results. The samples came mainly from Eucalyptus (Myrtaceae) and Eupatorium (Asteraceae) plants. The dehydration conditions of the samples influenced the L*a*b* colour parameters and the biological value. Unlike the protein and lipid content, the glucose and fructose content were unaffected. The vitamin E content (27.2 ± 0.3 μg/g, 27.5 ± 0.4 μg/g) in oven-dehydrated samples with forced air circulation was significantly lower (P < 0.05) compared with lyophilized samples (37.5 ± 0.2 g/100 g, 53.7 ± 3.9 g/100 g). Overall, the results were inconclusive for vitamin B complex, minerals and microbiological indicators. There was a positive correlation between the colour parameters L* and b* and the total phenolic content, as well as between phenolic content and the antioxidant and antimicrobial capacity. The data indicate that lyophilization might be a viable alternative to the current process, resulting in dehydrated bee-pollen with higher biological activity.
- HPLC- MS Flavonoid determination and antioxidant capacity of Brazilian dehydrated bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Almeida-Muradian, Ligia BicudoBee-pollen, produced by Apis mellifera bees, is an important source of proteins, lipids, vitamins and minerals for the hive, being considered one of nature's most completely nourishing foods. Its composition may vary according to the geographical region and its quality is influenced by harvest method and processing conditions. Although it has good nutritional components, beepollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity. The present study aimed to evaluate the flavonoid composition, using HPLC-MS technique; and the antioxidant activity, using two different methods (DPPH and ORAC), of eight dehydrated bee-pollen samples collected in different Brazilian apiaries. The sample with the highest antioxidant capacity using DPPH method was produced in Rio Grande do Sul State (110.85 mol TE/g) while the sample with the least antioxidant capacity was collected in Bahia State (9.97 mol TE/g). The same sample from Rio Grande do Sul State presented the highest antioxidant capacity using ORAC method (542.00 mol TE/g), while the lowest value was observed in a sample from Mato Grosso State (133.70 mol TE/g). The flavonoid analysis using HPLC-MS revealed the following variations: catechin (0.69 to 0.75 mg/100 g); naringenine (4.57 to 18.36 mg/100 g); rutin (3.36 to 46.80 mg/100 g); quercetin (1.86 to 67.91 mg/100 g) and kaempferol (5.50 to 44.97 mg/100 g). In the sample with the highest antioxidant capacity (Rio Grande do Sul State) was observed 40 peaks in the HPLC-MS, while the samples with the lowest antioxidant capacities the number of peaks were 25 (Mato Grosso State) and 22 (Bahia State); therefore, the variety of compounds may have influenced the antioxidant capacity of the samples.
- Influência do processo de desidratação sobre a atividade antimicrobiana do pólen apícola desidratadoPublication . De-Melo, Adriane A.M.; Tolentino, Georgina Santos; Estevinho, Leticia M.O objetivo deste estudo foi investigar a influência do processo de conservação na ativi-dade antimicrobiana de amostras de pólen apícola do Brasil contra microorganismos isolados de fluidos biológicos e estirpes de referência.Amostras de pólen apícola foram coletadas durante os meses de abril/2012 e setem-bro/2012 em um apiário localizado no Estado de São Paulo, Brasil. Parte das amostras foi subme-tida a desidratação por aquecimento em estufa a 42ºC e parte a desidratação por liofilização. A atividade antimicrobiana foi determinada pelo método de microdiluição em placa [1], na Escola Superior Agrária de Bragança. Como material biológico foram utilizadas bactérias Gram-positi-vas (Streptococcus pyogenes ATCC; Streptococcus pyogenes ESA12; Staphylococcus aureus ATCC 6538™; Staphylococcus aureus ESA54), bactérias Gram-negativas (Escherichia coli ATCC 25922™; Escherichia coli ESA72; Klebsiella pneumoniae ATCC 13883™; Klebsiella spp) e leveduras (Candida albicans ATCC 10231™ e Candida albicans ESA109). Os resultados foram expressos em concentra-ção minima inibitória (CIM; p/v), que é a menor concentração de extrato de pólen apícola capaz de inibir o crescimento microbiano indicado por coloração com cloreto de trifenil tetrazolium (TTC).Todos os extratos apresentaram atividade antimicrobiana. A CIM para bactérias Gram--positivas variou entre 1,4 e 5,3%, enquanto que, para as bactérias Gram-negativas os valores obtidos oscilaram entre 2,5 e 7,0% e para as leveduras entre 16,7 e 25,8%. As amostras liofilizadas exerceram um efeito mais acentuado na inibição de crescimento de todos os microrganismos em estudo comparativamente com as amostras secas em estufa, sugerindo que o aquecimento pode ter alterado os compostos com propriedades antimicrobianas.Grande parte dos produtores de pólen apícola utiliza a desidratação por aquecimento em suas unidades de processamento, no entanto, este estudo indica que a liofilização pode ser uma alternativa ao processo atual que resulte num produto de maior potencial biológico. O consumo de pólen apícola é impulsionado pela demanda por produtos naturais com propriedades tera-pêuticas, portanto, quanto maior o potencial biológico deste produto, maior será a sua procura.
- A multivariate approach based on physicochemical parameters and biological potential for the botanical and geographical discrimination of Brazilian bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia BicudoFifty six Brazilian bee pollen samples were characterised, and their botanical and geographical origins were studied. The samples were also classified based on physicochemical and biological properties. The characterisation was done using Soxhlet extraction and micro-Kjeldahl methods, ashing at 550°C, transmittance, microscopy, spectrophotometry, inductively coupled plasma optical emission spectrometry and high-performance liquid chromatography. As expected, the values of proteins (7.9–32.2g/100g), lipids (3.2–13.5g/100g), ash (1.9–3.6g/100g), carbohydrates (54.9–82.8g/100g), K (3.4–9.8g/kg), Ca (0.9–4.1g/kg), Mg (0.6–2.4g/kg), Fe (46–1180mg/kg), Na (20–374mg/kg), Mn (25–215mg/kg), Zn (30–101mg/kg), Cu (7.4–19.7mg/kg), total phenolics (6.5–29.2mgGAE/g)and flavonoids(0.3–17.5mgQE/g)as well as the phenolic profiles varied among the samples. In general, the products had high antioxidant capacity (ORAC: 133–563 μmol TE/g; DPPH: 9.4–155μmolTE/g) and the antimicrobial capacity varied according to the sample and microorganism tested. The instrumental colour parameters could be used as indicators of some minerals. Based on multivariate approaches, bee pollen from Southern Brazil seemed to have a higher biological potential, whereas products from the Northeast region had higher calcium and magnesium levels. Similarities were identified in bee pollen containing C. nucifera or Brassica, and monofloral bee pollen seemed to have higher mineral content than heterofloral bee pollen.
- Phenolic profile and antioxidant capacity from 56 brazilian dehydrated bee-pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Almeida-Muradian, Ligia BicudoBee-pollen is a food produced by bees from the flower pollen, to be a source of proteins, lipids, vitamins and minerals for the hive [1]. Its composition varies according to the region where it is produced, and its quality is influenced by the collection and processing conditions [2, 3]. Besides nutritional substances, bee-pollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity [4]. The present study aimed to evaluate the polyphenolic profile and antioxidant activity of 56 dehydrated bee-pollen samples by high performance liquid chromatography and in vitro assays. Bee-pollens samples, collected during November 2011 to December 2013 from apiaries located in different Brazilian regions, were extracted with stirring for 30 minutes with ethanol 70% at 70 ºC and analyzed. The total phenolic content ranged from 6.5 ± 0.2 to 29.2 ± 0.3 mg gallic acid equivalent/g dry sample and flavonoid content ranged from 0.35 ± 0.01 to 17.5 ± 0.1 mg quercetin equivalent/g dry sample. The antioxidant activity assays, with values of 9.4 ± 0.4 to 155 ± 5 mol Trolox equivalent/g dry sample for DPPH and 133 ± 2 to 563 ± 15 mol TE/g for ORAC methods, revealed the antioxidant capacity of bee-pollen extracts. Regarding, the characterization of the phenolic composition from the several extracts by HPLC-PAD it was possible to observe that rutin, quercetin and vanillic acid were the main phenolic compounds found in the Brazilian dehydrated bee-pollen analyzed. On the other hand, caffeic acid was found in less amounts in the majority of samples studied. Among the identified polyphenols, only quercetin seems to have influenced positively in the antioxidant capacity of the samples. The Pearson’s Correlation analysis indicated high correlation between quercetin and ORAC values (r=0.6570, p=0.000) and medium correlation between quercetin and DPPH values (r=0.4873, p=0.000). In conclusion, bee-pollen characteristics vary according to the botanical origin and the Brazilian region where the sample was produced. This is a product with high antioxidant potential, therefore other tests, especially bioavailability assays, should be performed.
- Phenolic profile by HPLC-MS, biological potential, and nutritional value of a promising food: Monofloral bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia BicudoThe objective of this study was to determine physicochemical and phenolic profiles as well the antioxidant and antimicrobial capacities of monofloral bee pollen samples from Brazil. Traditional methods were used. The phenolic profile was determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The protein (10.6–33.9 g/100g), lipids (3.2–8.3 g/ 100g), ashes (2.6–3.8 g/100g), total phenolic (5.6–29.7 mg GAE/g), and total flavonoid (0.3– 19.0 mg QE/g) values were variable, even between products with the same botanical origin. The minerals analyzed were found in amounts varying between 10 mg/kg and 9.1 g/kg. Each product presented specific color parameters. Myrcia bee pollen presented the greater antioxidant capacity, and Mimosa scabrella bee pollen from Santa Catarina state was the most efficient in inhibiting bacteria and yeasts. Among the compounds identified by HPLC-MS, flavonoid 3-O-glycosides predominated. The physicochemical and phenolic profiles of each sample were distinct, and there was no pattern between monofloral products of the same pollen type.