Mycotoxicological and palynological profiles of commercial brands of dried bee pollen

Abstract Pollen is used in the human diet as a food supplement because of its high nutritional value; however, this product is prone to fungal contamination that could potentially generate toxins that are harmful to human health. This study aimed to verify the floral diversity of commercial brands of bee pollen and their mycotoxicological safety for human consumption. A total of 27 bee pollen samples were analyzed; these samples represented commercial brands, either showing an inspection seal or not, marketed in the State of Rio de Janeiro. The analyzed parameters included floral diversity through palynological analysis, water activity, fungal counts, identification and toxigenic profiles. The palynological analysis identified nine plant families, of which the Asteraceae was predominant. Analysis of hygienic quality based on fungal load showed that 92% of samples were reproved according to the commercial, sanitary, and food safety quality indicators. Aspergillus, Cladosporium and Penicillium were the most common genera. Toxigenic evaluation showed that 25% of the A. flavus strains produced aflatoxins. The high rate of contamination of products bearing an inspection seal emphasizes the need to monitor the entire procedure of bee pollen production, as well as to revise the current legislation to ensure safe commercialization of this product.

Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de La Muerte, Costa Rica

Although sugar-water feeders are commonly used by enthusiasts to attract hummingbirds, little is known about how they affect hummingbird behavior and flower use. We studied the highland hummingbird assemblage of Cerro de La Muerte, Costa Rica, both at a site with permanent feeders (La Georgina Restaurant) and further from it. We examined how feeder use and monopolization affected seasonal changes in pollen loads during four sampling periods, including dry and wet seasons, from 2003-2005. We expected that species monopolizing the feeders would carry little or no pollen whatsoever, and would have pollen loads characterized by low floral diversity, in contrast with species less dependent on feeders. We obtained pollen samples from 183 individuals of four hummingbird species captured around the feeders using mist nets, which were compared with a pollen reference collection of plants with a pollination syndrome by hummingbirds. The same methods were implemented at a site 3km away from the feeders. Feeder usage was quantified by counting the number of times hummingbirds drank from the feeders in periods of 4min separated by 1min. The effects of hummingbird species and season on pollen load categories were assessed using a nominal logistic regression. The alpha species at the site, the Fiery-throated Hummingbird (Panterpe insignis), dominated the feeders during the dry season. Meanwhile, in the wet season, feeder usage was more evenly distributed across species, with the exception of the Volcano Hummingbird, Selasphorus flammula, which occupies the last place in the dominance hierarchy. Pollen loads of hummingbirds captured near feeders were low in abundance (more than 50% of captured individuals had zero or low pollen loads), and low in species richness (96% of the hummingbirds with pollen from only one plant genus, Centropogon). Overall pollen loads increased during the dry season coinciding with peaks in flower availability, although the ...

El uso de comederos constituye una práctica común para atraer colibríes, a pesar de que sabemos poco acerca de sus efectos sobre las relaciones ecológicas entre colibríes y sus plantas asociadas. Estudiamos el grupo de colibríes del Cerro de La Muerte, Costa Rica, en un sitio con comederos permanentes (Restaurante La Georgina), así como en un lugar alejado de los comederos. Analizamos cómo el uso y monipolización estacional de los comederos afectaba la carga de polen en cuatro períodos de muestreo entre 2003 y 2005. Esperábamos que las especies que monopolizaban los comederos tuvieran poco o cero polen, y si lo presentaban que la carga de polen estuviera representada por pocas especies en comparación con especies menos dependientes de los comederos. En la estación seca, la especie alfa Panterpe insignis, dominó los comederos. En la estación lluviosa el uso de comederos fue más equitativo. La carga de polen fue muy baja en abundancia (50% de los colibríes tenían poco o cero polen) y diversidad (96% de los colibríes tenían polen solamente del género Centropogon). Encontramos una relación competitiva y antagonística entre la visitación de comederos y la abundancia de flores. La carga de polen aumentó en la estación seca al haber más flores, aunque la mayoría de los colibríes capturados no tenían polen. Durante la estación lluviosa, cuando hay menos flores disponibles, el uso de comederos aumenta y la carga de polen disminuye. El uso de comederos interfiere en redes de polinización y se combina con otros efectos antropológicos negativos, tales como el calentamiento global, fragmentación de hábitats, cambio en el uso del suelo, que hacen más difícil la conservación de complejas redes tróficas.

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.

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.

ABEJAS VISITANTES DE Mimosa pigra L. (MIMOSACEAE): COMPORTAMIENTO DE PECOREO Y CARGAS POLÍNICAS / Bees visiting Mimosa pigra L. (Mimosaceae): foraging behavior and pollen loads

Se estudiaron las cargas polínicas de 13 taxones de abejas capturadas visitando a Mimosa pigra en la zona de influencia del Embalse Porce II (Antioquia, Colombia). De los 21 tipos polínicos encontrados, M. pigra presenta el mayor porcentaje acumulado de colecta; Mimosa pudica, Piper aduncum, Solanum diversifolium, Warszewiczia coccinea y Psidium guajava, en su orden, se pueden considerar fuentes alternativas de polen, para varias de las especies de abejas cuyas cargas polínicas fueron analizadas. Dentro de las especies de abejas capturadas visitando a M. pigra se pueden diferenciar varios grupos según el tipo y abundancia relativa de los tipos polínicos encontrados en sus cargas. Uno de ellos, incluye a siete especies de abejas con más del 85% de granos de polen de M. pigra; otro, con cuatro especies de abejas que colectaron más del 94,5% del polen en M. pigra y M. pudica. Adicionalmente, se encontraron especies como Trigona dorsalis con cargas de M. pigra (59,4%), de S. diversifolium (37,8%) y especies de abejas como Lasioglossum sp. 113, en cuyas cargas polínicas predominan los granos de polen de P. aduncum (61,8%) y de W.coccinea (36,4%), en contraste con los de M. pigra (1,3%). En cuanto a la riqueza de tipos polínicos colectados por las abejas sobresalen Trigona muzoensis (12 tipos polínicos) y T. dorsalis (10 tipos), lo cual refleja nichos tróficos más amplios para estas especies y deja duda sobre su constancia floral o hábitos de limpieza.

We studied the pollen loads of 13 taxa of wild bees visiting the flowers of Mimosa pigra on the influence zone of the Dam Project Porce II (Antioquia, Colombia). Out of 21 different pollen types, M. pigra represents the higuest percentage; Mimosa pudica, Piper aduncum, Solanum diversifolium, Warszewiczia coccinea and Psidium guajava, in that order, were also abundant, and are alternative sources of pollen for the different kinds of bees recorded. Among the species of bees collected, we differentiate several groups: one of them, includes seven species of bees whose pollen loads are in a high porcentaje of M. pigra (86% of pollen grains or above); another group of bees with high percentage (more than 94%) of pollen grains of Mimosa species (M. pigra and M. pudica); and the other two groups that include the bee species: Trigona dorsalis (who collected more than half of their pollen resources from M. pigra (59.4%) in addition to a high percentage of S. diversifolium (37.8%); the last kind of foragers includes Lasioglossum sp.113 who collected mostly pollen from species different to Mimosa (including P. aduncum with 61.8% of pollen grains, and W. coccinea with 36,4%) and only a small percentage of M. pigra (1,3%). In terms of the species of bees that collected a highest diversity of pollen grains, two species: Trigona muzoensis (12 pollen types) and T. dorsalis (10 pollen types) outstand other species of bees on on feeding niche and question either the bees capacity of cleaning or their floral constancy.