A potentiometric electronic tongue for the discrimination of honey according to the botanical origin. Comparison with traditional methodologies:Physicochemical parameters and volatile profile

摘要

The effectiveness of a potentiometric electronic tongue, made of various metals and metallic compounds was evaluated for the differentiation of honey in three different states: raw, liquefied and pasteurized. Principal component analysis (PCA) and a neural network showed that potentiometric electrodes seem useful to classify honey by its botanical origin, though they do not seem capable of discrimination between applied thermal treatments. The same was observed in the samples for physicochemical parameters and volatile compounds analysed with PCA. Au, Cu and Ag electrodes were more decisive in the discrimination of honey. A remarkable correlation (PLS analysis) between the electronic tongue and the physicochemical parameters was found, the best results being for color Pfund (r~2= 0.958), L~* (r~2 = 0.935) and diastase activity (r~2 =0.926). The correlation with volatile compounds was much weaker, though this improved for specific characteristic compounds in each monofloral variety. Thus, this is a good starting point for the development of new systems focused on the honey sector.