Voltammetric E-Tongue for Honey Adulteration Detection.

Paula Ciursa,Mircea Oroian

doi:10.3390/s21155059

Abstract

The aim of this study is to establish the usefulness of an electronic tongue based on cyclic voltammetry e-tongue using five working electrodes (gold, silver, copper, platinum and glass) in honey adulteration detection. Authentic honey samples of different botanical origin (acacia, tilia, sunflower, polyfloral and raspberry) were adulterated with agave, maple, inverted sugar, corn and rice syrups in percentages of 5%, 10%, 20% and 50%. The silver and copper electrodes provided the clearest voltammograms, the differences between authentic and adulterated honey samples being highlighted by the maximum current intensity. The electronic tongue results have been correlated with physicochemical parameters (pH, free acidity, hydroxymethylfurfural content—5 HMF and electrical conductivity—EC). Using statistical methods such as Linear discriminant analysis (LDA) and Support vector machines (SVM), an accuracy of 94.87% and 100% respectively was obtained in the calibration step and 89.65% and 100% respectively in the validation step. The PLS-R (Partial Least Squares Regression) model (constructed from the minimum and maximum current intensity obtained for all electrodes) was used in physicochemical parameters prediction; EC reached the highest regression coefficients (0.840 in the calibration step and 0.842 in the validation step, respectively), being followed by pH (0.704 in the calibration step and 0.516 in the validation step, respectively).

Highlights

Honey is a food product with a high nutritional value known since ancient times for its organoleptic and therapeutic characteristics [1]
Honey must be evaluated because the price is being established based on botanical origin and the presence of adulterants [2]
A fast technique is needed to detect the lowest degree of adulteration

Summary

Introduction

Honey is a food product with a high nutritional value known since ancient times for its organoleptic and therapeutic characteristics [1]. Honey must be evaluated because the price is being established based on botanical origin and the presence of adulterants [2]. Among the negative effects of adulterated honey on consumer health are: high blood sugar, weight gain, high blood pressure due to high blood lipids [3]. The honey sector does not require data on the exact degree of adulteration, because the addition of any other substances is prohibited. A fast technique is needed to detect the lowest degree of adulteration. Among the most promising techniques that meet these requirements, in addition to being more environmentally friendly than ordinary methods, electronic tongue (e-tongue) has the advantage of being able to be an alternative tool to traditional analytical methods [4]. Electronic tongue can be used in the qualitative [5] and quantitative characterization of multicomponent [6]

Objectives

Methods

Results