Volatile Organic Compounds from Offspring of Stingless Bee Sacrificed in Hygienic Behavior Test.

This study shows the profile of volatile organic compounds (VOCs) from pupae and larvae of Melipona quadrifasciata anthidioides Lepeletier subjected to three death induction techniques for hygienic behavior (HB) studies: freezing in liquid nitrogen (LN2), freezing in a freezer (FRZ) and piercing of offspring with an entomological pin (PIN). The VOCs from larvae and pupae were obtained through headspace solid-phase microextraction and characterized using gas chromatography coupled to mass spectrometry. In addition, an HB test was performed on the colonies. The main classes of VOCs were hydrocarbons, terpenes and alcohols. Multivariate analysis was applied and showed that there was a separation in the compound profiles between the different treatments. The HB test in the colonies showed that 24 hours after the application of the techniques, the bees removed more dead larvae in LN2 treatment (83.5 %), while after 48 hours more larvae were removed in the LN2 and FRZ treatments (92.3 %). When compared to pupae removal, larvae removal was significantly faster in LN2.

Efficiency of two digestion methods in determining the presence of metals (Cd, Cu, Cr, Pb and Zn) in geopropolis produced by Melipona scutellaris / Eficacia de dos métodos de digestión para determinar metales (Cd, Cu, Cr, Pb y Zn) en geopropóleos producidos por Melipona scutellaris / Eficiência de dois métodos de digestão para determinar metais (Cd, Cu, Cr, Pb e Zn) na geoprópolis produzida por Melipona scutellaris

Abstract This study evaluates the efficiency of acid extraction and total digestion to determine the presence of metals in geopropolis produced by the stingless bee Melipona scutellaris. Geopropolis samples were collected at five meliponaries in the city and in the metropolitan region of Salvador, Bahia State, Brazil. The sample treatment methods comprised acid extraction and total digestion. The Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) technique was used to quantify Cd, Cu, Cr, Pb, and Zn. Geopropolis samples submitted to both digestion methods showed statistical differences. For both methods, Cr and Zn showed the highest concentrations, while those of Cd were the lowest. The Cr concentration for determination by total digestion was 37.53 mg/kg, while for acid extraction it was 32.90 mg/kg. For Zn, the concentration was 17.65 mg/kg and 8.85 mg/kg for total digestion and acid extraction, respectively. The total digestion method showed the highest concentrations of the metals evaluated; however, acid extraction (USEPA 3050b) is a more straightforward procedure for metal evaluation in geopropolis samples and presented values that support the use of geopropolis as a bioindicator. The acid extraction method USEPA 3050b, in combination with detection using ICP OES, showed efficiency in analyses carried out to determine metals in geopropolis.

Resumen El objetivo de este artículo fue evaluar la eficacia da extracción ácida y de la digestión total para determinación de metales absorbidos en geopropóleos producidos por Melipona scutellaris. Se colectaron muestras de geopropóleos en cinco meliponarios localizadas en la región metropolitana del Salvador, estado de Bahia, Brasil. Se utilizaron como métodos de tratamiento para muestras, la extracción ácida y la digestión total. Para determinar los metales Cd, Cu, Cr, Pb y Zn se utilizó Espectroscopia de Emisión Óptica con Plasma Acoplado Inductivamente (ICP OES). Se encontraron diferencias estadísticas en la concentración de metales hallados en las muestras de geopropóleos sometidas a los diferentes métodos de digestión. Para ambos métodos de digestión, las mayores concentraciones de metal fueron observadas para Cr y Zn. Entre los metales evaluados Cd presentó la menor concentración. La concentración de Cr para la determinación por digestión total fue de 37,53 mg/kg y para la extracción ácida fue de 32,90 mg/ kg. Para el Zn, la concentración fue de 17,65 mg/kg y 8,85 mg/kg para la digestión total y la extracción ácida, respectivamente. El método de digestión total mostró los mayores valores para concentraciones de los metales evaluados. Entretanto, la extracción ácida, USEPA 3050b, es un procedimiento más simple para la evaluación de metales en muestras de geopropóleos y también mostró valores que pueden satisfacer la necesidad de su uso en evaluaciones de colmenas como bio-indicador. El método de extracción ácida USEPA 3050b en combinación con la detección a través de ICP OES se mostró eficiente para el análisis de metales en geopropóleos.

Resumo O objetivo deste estudo foi avaliar a eficiência da extração ácida e da digestão total para determinação de metais adsorvidos na geoprópolis produzida por Melipona scutellaris. Foram coletadas amostras de geoprópolis em cinco meliponários, situados em Salvador, Estado da Bahia e região metropolitana. Foram utilizados como métodos de tratamento das amostras a extração ácida e a digestão total. Para determinação dos metais Cd, Cu, Cr, Pb e Zn utilizou-se a Espectrometria de Emissão Óptica com Plasma Indutivamente Acoplado (ICP OES). Houve diferença estatística na concentração de metais encontrados nas amostras de geoprópolis submetidas aos diferentes métodos de digestão. Para ambos os métodos de digestão as maiores concentrações de metais foi observada para o Cr e Zn. Dentre os metais avaliados o Cd apresentou a menor concentração. A concentração de Cr para determinação por digestão total foi de 37,53 mg/kg e para extração ácida de 32,90 mg/ kg. Para o Zn, a concentração foi de 17,65 mg/kg e 8,85 mg/kg para digestão total e extração ácida, respectivamente. O método de digestão total apresentou os maiores valores para concentrações dos metais avaliados. No entanto, a extração ácida, USEPA 3050b, é um procedimento mais simples para a avaliação dos metais em amostras de geoprópolis e também apresentou valores que podem satisfazer a necessidade de utilização na avaliação deste produto da colmeia como bioindicador. O método de extração ácida USEPA 3050b em combinação com a detecção por ICP OES mostrou eficiência para análise de metais em geoprópolis.

Chemical Composition and Biological Activities of Mono- and Heterofloral Bee Pollen of Different Geographical Origins.

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, ß-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.