Non-targeted method to detect honey adulteration: Combination of electrochemical and spectrophotometric responses with principal component analysis

Abstract

Detecting adulteration in honey is not an easy task and most of the traditional methods are usually unaffordable. Thus, we describe the use of cyclic voltammetry using Cu/CuO electrode and UV–vis spectrophotometry along with chemometric tools to detect adulteration of honey with corn syrup. Both honey and corn syrup samples presented an anodic peak at +1.1 V, but the current is variable and depends on the sample composition in relation to the honey and syrup content. A cathodic peak at +0.42 V arises at higher scan rates, which is more pronounced for syrup samples and can be used to discriminate between pure and adulterated samples. This response can be combined with UV/vis absorbance peaks at 285 and 216 nm to identify adulteration. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed differentiating between honey and corn syrup samples and simulated mixtures of them, in which the first two principal components together explain 100.0 % of the data variability, specifically 98.47 % by PC1 and 1.53 % by PC2. The method requires a minimum amount of sample and generates a low amount of waste. Furthermore, it is possible to use portable and cheap equipment, making it more accessible to the beekeeper sector.