Multi-trace metals determination of peninsular Malaysia stingless bee honeys from different regions and seasons using inductively coupled plasma-optical emission spectrometry and chemometric techniques

Abstract

Demand for authenticating and distinguishing the provenance of bee honey among consumers is continuously rising. Considering vast variations in prices attributable to different geographical origins, suitable indication on labeling of honey products is important for consumer protection. Since concentrations of trace metals can be closely related to geographical origin, the use of spectroscopy and chemometric techniques for ascertaining the validity of such claim may prove relevant. In this study, multi-trace metals in stingless bee honey of Heterotrigona itama species, from different regions and seasons (rainy and dry) in Peninsular Malaysia (Kedah, Johor, Selangor and Pahang) were determined via inductively coupled plasma-optical emission spectrometry (ICP-OES). Principal component analysis (PCA) was then applied to recognize the distribution patterns. Subsequently, linear discriminant analysis (LDA) was applied to perform further classification. With the use of LDA, cross-validation was found as 95.8% and 89.6% during rainy and dry seasons, respectively. Combination of ICP-OES data with PCA and LDA techniques has provided accurate classification of the Malaysian stingless bee honey samples according to their respective origins. This study provided some elemental information on distribution of stingless bee honey samples at spatial and temporal levels, and could be used as a reference for their provenance establishment and authenticity.