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Rogers K.M.,Institute of Geological & Nuclear Sciences | Cook J.M.,3125 Conner Blvd | Krueger D.,Krueger Food Laboratories Inc. | Beckmann K.,Quality Services International GmbH
Journal of AOAC International | Year: 2013

An international ring test was undertaken in 2012 among 10 international honey testing laboratories to examine the effects of filtration and/or centrifugation addition to AOAC 998.12 method (C4 sugar detection in honey). During protein extraction, when using the repetitive washing method, any insoluble material (i.e., pollen, dust) is coextracted along with protein which may result in contamination of the protein isotope value and result in a false-positive test. A modification step involving filtration and/or centrifugation to remove insoluble material before protein flocculation was proposed. Results were compared across 10 laboratories internationally and were found to be an excellent assessment of interlaboratory variability with the standard variances between laboratories better than ±0.2‰ for honey and ±0.3‰ for protein. Source

Kast C.,Swiss Bee Research Center | Dubecke A.,Quality Services International GmbH | Kilchenmann V.,Swiss Bee Research Center | Bieri K.,Institute of Pollen Analysis K. Bieri GmbH | And 4 more authors.
Journal of Apicultural Research | Year: 2014

Various studies have shown that honey may contain pyrrolizidine alkaloids (PAs) and thus can pose a potential health risk for consumers. It seems that the level of contamination depends on the geographical and botanical origin of the honey. The geographically central location of Switzerland within Europe accounts for various different climate zones, and therefore can serve as a model to study PA contamination in honeys. We analysed 71 honeys between 2009 and 2011. Honeys from various botanical origins were collected from regions north and south of the Alps as well as the alpine regions. The PA concentration of the honeys was determined by target analysis using an HPLC-MS/MS-system, allowing the detection of 18 different PAs and PA-N-oxides found in the genera Echium, Eupatorium and Senecio. 54% of the honeys contained PAs, while in 46% of the honeys PA concentrations were below the limit of quantitation (LOQ). The LOQs ranged from 1 μg/kg to 3 μg/kg, depending on the PA. The mean PA concentration of the positive samples was 6.7 μg/kg. The highest concentration of PAs (55 μg/kg) was found in a honey from Ticino, an area of the southern flank of the Alps. All the other positive honeys contained PAs at concentrations below 18 μg/kg. Therefore Swiss honey usually does not pose a risk for consumers. In the investigated honeys, honeys from the Swiss alpine regions (29 out of 37) tested more frequently positive for PAs compared to honeys from areas north of the Alps (9 out of 34). This probably reflects the different botanical settings of the central European and the alpine climate regions. © IBRA 2014. Source

Dubecke A.,Quality Services International GmbH | Beckh G.,Quality Services International GmbH | Lullmann C.,Quality Services International GmbH
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2011

A total of 3917 honey samples and 119 'bee pollen' samples (pollen collected by honeybees) were analysed for pyrrolizidine alkaloids (PAs). Some 0.05M sulphuric acid was used for extraction followed by a clean-up step by means of solid-phase extraction. Separation and detection was achieved by target analysis using an LC-MS/MS system. PAs were found in 66% of the raw honeys (bulk honey not yet packaged in containers for sale in retail outlets) and in 94% of honeys available in supermarkets (retail honey). A total of 60% of the bee pollen samples were PA positive. The PA pattern was used to identify the potential origin of the PAs in honey, which was verified for the genus Echium by relative pollen analysis. The results give an estimate of the impact of PA-containing plants belonging to the genera Echium, Senecio and, to a certain extent, Eupatorium on PA levels in honey and can serve as a decision basis for beekeepers in order to find the most suitable location for the production of honey and bee pollen low in PAs. © 2011 Taylor & Francis. Source

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