Multielemental characterization of honey using inductively coupled plasma mass spectrometry fused with chemometrics

Honey is considered a desirable ingredient in a range of different foodstuffs because of its nutrient and therapeutic effect. The honey characteristics mainly depend on the type of vegetation visited by the bees and the climatic conditions in which the plants are growing. Therefore, the purity, floral and geographical origin and authenticity are important factors influencing the overall perception of honey and honey-based products in terms of quality and price. An important parameter in this picture is the elemental composition of honey because it can be linked with the floral type of honey, floral plant density and the botanical origin of nectar and pollens. In this work, the concentration range variation of 18 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Mg, Mn, Na, Ni, K, Pb, Sr, Ti, V and Zn) was investigated in four varieties of honey (linden, acacia, rape, and sunflower) originating from Romania, because the elemental profile of honey may give important information to differentiate its geographical and varietal origin for authenticity purpose. All the determinations were carried out by inductively coupled plasma quadrupole mass spectrometry (ICP-Q-MS). The most abundant minerals decreased in the following order: K > Ca > Mg > Na, having the mean values of 248.70, 59.97, 20.54 and 11.92 mg kg^-1 , respectively. The mineral content marks the differences in honey samples from different botanical origin and can be used as a tool for authentication purposes and also extends its applicability to assess the traceability of honey. Analysis of variance showed the preliminary relationships between the elements and samples. Further, the discrimination between different studied honey samples was achieved by principal component analysis (PCA). The multivariate analysis of the data allowed us to separate the honey samples into distinct groups according to their macroelement and microelement composition, emphasizing the origin of variation of element concentrations by honey type. Therefore, this approach might be potentially useful for the control of honey quality, origin or authenticity, and even to use the honey as environmental tracer.

Monitoring trans-Resveratrol in Grape Berry Skins During Ripening and in Corresponding Wines by HPLC

Trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) is naturally present in the skin of grapes and therefore is expected to occur in grape products. Recently, there has been a renewal of interest in wine as medical treatment for various disorders. In this study, berry skins of five red grape varieties were analysed at weekly intervals for trans-resveratrol production, during 2012 and 2013 harvest. The obtained wines were also evaluated. Quantification of trans-resveratrol in grape skin extracts and wines was carried out by high-performance liquid chromatography. Favourable viticultural climate during harvest in 2012 resulted in a higher content of trans-resveratrol. The highest trans-resveratrol content was in Pinot Noir and Feteasca Neagra grape varieties, both in berry skins and wines, while the lowest amounts were identified in Cabernet Sauvignon variety. We can conclude that there was a significant correlation between the content of trans-resveratrol in grape skins and that in the respective wine.