Multi-element spectrometric analysis of stingless bee honey in Johor for forensic provenancing application

Abstract

Consumption of stingless bee honey as nutritious food supplement has been gaining popularity in many countries including Malaysia. However, its safe consumption following the possible presence of toxic amounts of trace elements remains unclear. Hence, this cross-sectional research that assessed the concentrations of multielements in purely harvested stingless bee honeys from bee keepers at four geographical locations (five districts) in Johor using inductively coupled plasmaoptical emission spectrometry deserves consideration. Even though the concentrations of As, Pb, Cd and Sb in all the purely harvested stingless bee honeys complied fully with the Malaysian Food Standard, however the Cd concentrations in samples from Kota Tinggi was found to be higher than the suggested value by the US Food and Drug Administration for food supplements. While the concentrations of Cu and Cr in pure stingless bee honey samples from Muar and Kota Tinggi alone exceeded the minimal risk levels (MRLs) for chronic oral exposure, higher concentrations than the prescribed MRL for chronic oral exposure of Se for long term effect as set by US Agency for Toxic Substances and Disease Registry (ATSDR) was found in all the pure samples. Except for Ba and Sn, significant variations (p < 0.05) in the concentrations of other elements in pure stingless bee honey samples collected from the five districts of Johor were observed. Statistical approach using Principle Component Analysis (PCA) demonstrated 87.0% correct classification and the classification improved to 96.2% with the use of Linear Discriminant Analysis (LDA). This indicates that discrimination was possible for the different geographical regions. Therefore, in view of minimizing threats towards public health and promoting better international acceptance for Malaysian stingless bee honeys, adoption of more stringent maximum permissible limits may prove necessary. Hence, utilization of multi-elements analysis coupled with chemometrics techniques for assigning the provenance of stingless bee honeys for forensic applications is supported.