Honey authentication using rheological and physicochemical properties

Abstract

The aim of this study was to evaluate the influence of honey botanical origins on rheological parameters. In order to achieve the correlation, fifty-one honey samples, of different botanical origins (acacia, polyfloral, sunflower, honeydew, and tilia), were investigated. The honey samples were analysed from physicochemical (moisture content, fructose, glucose and sucrose content) and rheological point of view (dynamic viscosity-loss modulus G″, elastic modulus G', complex viscosity η*, shear storage compliance-J' and shear loss compliance J″). The rheological properties were predicted using the Artificial Neural Networks based on moisture content, glucose, fructose and sucrose. The models which predict better the rheological parameters in function of fructose, glucose, sucrose and moisture content are: MLP-1 hidden layer is predicting the G″, η* and J″, respectively, MLP-2 hidden layers the J', while MLP-3 hidden layers the G', respectively. The physicochemical and rheological parameters were submitted to statistical analysis as follows: Principal component analysis (PCA), Linear discriminant analysis (LDA) and Artificial neural network (ANN) in order to evaluate the usefulness of the parameters studied for honey authentication. The LDA was found the suitable method for honey botanical authentication, reaching a correct cross validation of 94.12% of the samples.

Keywords: ANN; Authentication; LDA; PCA; Rheology.

Fig. 1

Typical rheogram for honey: rhombus—G″, triangle—η*, square—G″, cross—J′, multiplication—J″

Fig. 2

Principal component analysis scores of the honey samples: A—acacia, H—honeydew, P—polyfloral, T—tilia, S—sunflower

Fig. 3

Linear discriminant analysis of honeys using physicochemical and rheological parameters: rhombus—acacia, square—tilia, triangle—polyfloral, cross—honeydew, multiplication sign—sunflower