Recent research shows variations in pollen chemical constituents and, consequently, in their therapeutic properties. Mono and multifloral bee pollen extracts were investigated for antioxidant and enzyme inhibitory activity properties, phenolic compounds and fatty acid composition. Generally, Eucalyptus spp. and multifloral extracts exhibited potent inhibitory activity against α-amylase, acetylcholinesterase, tyrosinase, lipoxygenase, lipase and hyaluronidase. On the other hand, Miconia spp. demonstrated higher antihemolytic activity. Cocos nucifera and Miconia spp. extracts exhibited important antioxidant properties in the different assays (ABTS, DPPH, β-carotene/linoleic acid and reducing power). Moreover, these extracts had greater amounts of total phenols and flavonoids in comparison to others. The increase in antioxidant activity (decrease in EC50 values) was accompanied by an increase in the amount of total phenols in the extracts. The pollen extracts contained linoleic acid and α-linolenic acid as major fatty acids, followed by palmitic acid, and oleic acid. In this study, differences were observed in both chemical constituents and biological activities of the samples related to the geographical and botanical origin of bee pollen.

Traditionally, melissopalynological and physicochemical analyses have been the most used to determine the botanical origin of honey. However, when performed individually, these analyses may provide less unambiguous results, making it difficult to discriminate between mono and multifloral honeys. In this context, with the aim of better characterizing this beehive product, a selection of 112 Lavandula spp. monofloral honey samples from several regions were evaluated by association of multivariate statistical techniques with physicochemical, melissopalynological and phenolic compounds analysis. All honey samples fulfilled the quality standards recommended by international legislation, except regarding sucrose content and diastase activity. The content of sucrose and the percentage of Lavandula spp. pollen have a strong positive association. In fact, it was found that higher amounts of sucrose in honey are related with highest percentage of pollen of Lavandula spp.. The samples were very similar for most of the physicochemical parameters, except for proline, flavonoids and phenols (bioactive factors). Concerning the pollen spectrum, the variation of Lavandula spp. pollen percentage in honey had little contribution to the formation of samples groups. The formation of two groups regarding the physicochemical parameters suggests that the presence of other pollen types in small percentages influences the factor termed as “bioactive”, which has been linked to diverse beneficial health effects.

Sunflower (Helianthus annuus L.) is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae) and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination) were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2 nd and 3 rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum) than pollen collecting (0.40 bees per capitulum). On the 3 rd flowering day, Helio 360 and Aguará hybrids had higher (p ≤ 0.05) number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p ≤ 0.05) from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators.

Melipona scutellaris (Apidae, Meliponini) is one of the main species of stingless bees used in beekeeping in the Northeast of Brazil. We examined the honey from M. scutellaris as an indicator to evaluate the levels of metals at sampling sites subject to a broad spectrum of environmental pollutants. The collections were carried out in the urban-industrial area of Salvador, Bahia and the metropolitan region. Samples (n= 58) were submitted to the nitroperchloric digestion procedure. We used the inductively coupled plasma optical emission spectrometry technique (ICP OES) to determine the concentration of metals (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) in the samples. The studied metals were detected among the samples, which presented tolerable levels according to current Brazilian legislation and recommendations from the World Health Organization (WHO), except for Cr, which presented mean values higher than the threshold for all sampling sites. The detection of the analyzed metals indicates that the honey of M. scutellaris is a useful tool to evaluate the presence of environmental contaminants; therefore, it can be considered a good indicator of environmental contamination for monitoring a particular region and preventing issues due to the release of metals into the environment.

In this study, performed in the western part of the state of Paraná, Brazil, two self-fertile hybrid commercial rapeseed genotypes were evaluated for yield components and physiological quality using three pollination tests and spanning two sowing dates. The treatments consisted of combinations of two rapeseed genotypes (Hyola 61 and Hyola 433), three pollination tests (uncovered area, covered area without insects and covered area containing a single colony of Africanized Apis mellifera honeybees) and two sowing dates (May 25th, 2011 and June 25th, 2011). The presence of Africanized honeybees during flowering time increased the productivity of the rapeseed. Losses in the productivity of the hybrids caused by weather conditions unfavorable for rapeseed development were mitigated through cross-pollination performed by the Africanized honeybees. Weather conditions may limit the foraging activity of Africanized honeybees, causing decreased cross-pollination by potential pollinators, especially the Africanized A. mellifera honeybee. The rapeseed hybrids respond differently depending on the sowing date, and the short-cycle Hyola 433 hybrid is the most suitable hybrid for sowing under less favorable weather conditions.

Eight sunflower genotypes were analyzed to estimate correlation values for nine agronomic traits. Path analysis was used to partition the correlation values into direct and indirect effects on seed yield in two pollination tests (open and restricted pollination). In both tests, there were significant (p<0.05) positive correlation values between seed yield and head diameter, head mass, number and mass of achenes per head and first and last count of germination. There was no correlation (p≥0.05) between seed yield and 1000 seed weight in both pollination tests. Oil content was not correlated (p≥0.05) with seed yield in the open pollination, but it was positively correlated (p<0.05) in restricted plants. The path analysis, in both pollination tests, indicated that head mass had the highest direct effect on seed yield. It can be concluded that the variables head mass and number of seeds per inflorescence (for pollination open) should get due attention in sunflower breeding programs, indirectly contributing to seed yield. In addition, for both pollination tests, the number of seeds per inflorescence has high significant positive correlation to the oil content and may contribute to its increase.

The Southern region of Brazil is known for its floral diversity, presenting great potential for bee products such as honey, pollen, propolis and royal jelly. In this study, 67 honey samples provided by beekeepers from 14 municipalities of western Paraná were evaluated. Physicochemical parameters, bioactive compounds and antioxidant activity were analyzed. The physicochemical parameters of the samples were in compliance with the specifications by national and international standards, presenting average values of 3.26, 34.54 meq.kg-1 , 18.75%, 10.79 mg.kg-1 , 0.14% and 340.10 µS.cm-1 , for pH, acidity, moisture, hydroxymethylfurfural, ash content and electrical conductivity, respectively. The nutritive values of honey, on average, achieved 0.28% of protein from 69.09% of total sugars, 64.57% of reducing sugars and 4.28% of sucrose. Bioactive compounds showed average values of 34.83 mg GAE/100 g-1 of total phenols and 16.26 mg EQ/100 g-1 of flavonoids, enabling antioxidant activity of 2.68 µmol FE (II)/g-1 of FRAP, 1.01 µmol ET/g-1 from ABTS and 0.12 µmol ET/g-1 of DPPH. This first study evaluated the parameters through cluster analysis and observed nine groups formed, as well as the characteristics between the samples with similar reaction. We concluded that the honey samples have high similarity and confirmed the quality of the honey produced.

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