Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

<p>Abstract</p> <p>Background</p> <p>Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated.</p> <p>Results</p> <p>Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique.</p> <p>Conclusions</p> <p>The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.</p

Comparison of methods for determining moisture content of citrus and eucalyptus Brazilian honeys by refractometry

The official method in Brazilian legislation for determining moisture content in honey is the one established by the Association of Official and Analytical Chemists (AOAC). Recently, the European Honey Commission (EHC) proposed a modification of this method suggesting a pre-treatment for crystallized honey samples. The objectives of the present work were: to study by factorial design the influence of pre-treatment and physical state of sample on moisture content determined by refractometry; to choose the better procedure and determine the average value of moisture content of 50 citrus and eucalyptus honey samples. Samples were collected in Sao Paulo State, Brazil during 1996-1998. An Abbe Refractometer thermostatted at 20 degreesC was used and the pre-treatment was done in a water bath at 50 degreesC until crystal dissolution. The effects of the variables of factorial design (pre-treatment and physical state) were significant at 95% level. Results of this design showed that the use of the pre-treatment, suggested by EHC, is superior for analysis of liquid and crystallized honey samples. The moisture values obtained for eucalyptus were higher than those for citrus honey samples independent of the analysis method used. (C) 2001 Academic Press.14110110

Characterization of monofloral honeys by ash contents through a hierarchical design

With increasing world interest in honey characterization various studies have been carried out relating physicochemical parameters to botanical and geographical origins. Ash content is one of these parameters that has been associated with floral sources of honey samples. However, little attention has been given to the determination of how much of the variability in ash contents is caused by contributions of different floral sources or honey samplings compared to the variations caused by analytical errors. So, in this work, a two stage hierarchical statistical design is employed to quantify the sizes of these different variational sources. An extremely significant effect on ash content owing to floral origin of Eucalyptus and Citrus honey samples was found. A smaller but significant variation was also observed for different samples from the same floral source. This sampling variance can be associated with different environmental and geographical conditions, different technological aspects of production and processing of honeys since the honey samples were obtained from various beekeepers and collected in diverse regions of Sao Paulo State, Brazil. Considering that the variation owing to floral source is much larger than the one observed for sampling and analysis errors, ash content could be used to characterize these two types of monofloral honeys. (C) 2003 Published by Elsevier Inc.17673774

Evaluation of the botanical origin of commercial dry bee pollen load batches using pollen analysis: a proposal for technical standardization

High quality of bee pollen for commercial purpose is required. In order to attend the consumer with the best identification of the botanical and floral origin of the product, 25 bee pollen batches were investigated using two techniques of pollen grain preparation. The first started to identify pollen loads of different colors in two grams of each well mixed batch, and the second to identify pollen grains in a pool made of all the pollen loads comprised in two grams. The best result was obtained by this last technique, when a pollen grain suspension was dropped on a microscope slide and circa 500 pollen grains were counted per sample. This analysis resulted in the recognition of monofloral and bifloral pollen batches, while the use of the first technique resulted in all samples receiving a heterofloral diagnosis.<br>É exigida alta qualidade para a comercialização de pólen apícola. A fim de atender o consumidor com a melhor identificação da origem botânica e floral do produto, 25 partidas de pólen apícola feram investigadas usande duas diferentes técnicas na preparação dos grãos de pólen. A primeira partiu da identificação das cargas polínicas contidas em dois gramas de cada partida bem misturada segundo suas cores. A segunda visava identificar os grãos de pólen de um agrupamento ("pool") de todas as cargas polínicas contidas em dois gramas de cada amostra. O melhor resultado foi obtido pela última técnica, quando uma suspensão de grãos de pólen era gotejada sobre uma lâmina de microscopia e cerca de 500 grãos de pólen eram centades por amostra. Esta análise resultou no reconhecimento de partidas monoflorais e biflorais de pólen apícola, enquanto que usando a primeira técnica, todas as amostras receberam a diagnose heterefloral