The Use of Right Angle Fluorescence Spectroscopy to Distinguish the Botanical Origin of Greek Common Honey Varieties

Abstract

The standardization of the botanical origin of honey reflects the commercial value and quality of honey. Nowadays, most consumers are looking for a unifloral honey. The aim of the present study was to develop a novel method for honey classification using chemometric models based on phenolic compounds analyzed with right angle fluorescence spectroscopy, coupled with stepwise linear discriminant analysis (LDA). The deconstructed spectrum from three-dimensional-emission excitation matrix (3D-EEM) spectra provided a correct classification score of 94.9% calibration and cross-validation at an excitation wavelength (λex) of 330 nm. Subsequently, a score of 81.4% and 79.7%, respectively, at an excitation wavelength (λex) of 360 nm was achieved. Each chemometric model confirmed its power through the external validation with a score of 82.1% for both. Differentiation could be correlated with hydroxycinnamic and hydroxybenzoic acids, which absorb in this region of the spectrum. Fluorescence spectroscopy constitutes a rapid and sensitive technique, which, when combined with the stepwise algorithm and LDA method, can be used as a reliable and predictive authentication tool for honey. This study indicates that the developed methodology is a promising technique for determination of the botanical origin of common Greek honey varieties. Our long-term ambition is to support producers and suppliers to remain in a competitive national and international market.

Unifloral Autumn Heather Honey from Indigenous Greek Erica manipuliflora Salisb.: SPME/GC-MS Characterization of the Volatile Fraction and Optimization of the Isolation Parameters

“…Samples were produced during the 2019-2021 harvest period. The botanical origin was assessed by the beekeepers and then confirmed by melissopalynological [22], and physiochemical analysis [23,24], as previously described [25]. Floral origin was confirmed firstly according to European [26] and secondly according to the more strict Greek [27] legislation (sum of fructose and glycose not less than 60% w/w; sucrose content not more than 5% w/w; moisture content not more than 20% w/w; electrical conductivity not more than 800 (µS cm −1 ); diastase activity (Schade scale) not less than 8; HMF not more than 40 mg kg −1 ; heather pollen not less than 45%).…”

Combined Application of Fluorescence Spectroscopy and Principal Component Analysis in Characterisation of Selected Herbhoneys

“…The other tested herbhoneys practically do not show fluorescence bands in this range of emission wavelengths. The presence of several polyphenolic compounds is also evident, including gallic acid, vanillic acid, methyl syringate and catechin [ 7 ]. In the case of catechin (λ = 315 nm), small amounts can be found in the samples of raspberry, rose and nettle herbhoneys, while the highest fluorescence intensity was found for the sample of black currant.…”

“…Fluorescence spectroscopy is the other technique with broad application in food analysis. It is also a fast method with higher sensitivity than other spectroscopic tools, with a quantification limit reaching 1 ppb; it is simple, reliable, non-destructive (similar to NIR) and economical [ 6 , 7 , 8 ]. Fluorescence spectroscopy has been validated for the quality control and analysis of a wide range of foods, including dairy products, oils and honey [ 9 ].…”

“…Fluorescence spectroscopy has been validated for the quality control and analysis of a wide range of foods, including dairy products, oils and honey [ 9 ]. Fluorescence properties of honey and honey-like substances may be attributed to their phenolic constituents, amino acids, protein, vitamins, products of the Maillard reaction, and chlorophylls [ 7 , 10 , 11 ]. One of these products, hydroxymethylfurfural (HMF), is used as an indicator of honey freshness or heating [ 12 ].…”

Application of Canonical Variate Analysis to Compare Different Groups of Food Industry Companies in Terms of Financial Liquidity and Profitability

“…Due to the correlations between financial indicators, multivariate methods were used to analyze the group structure of enterprises. Canonical variate coordinates are directions in multivariate space that maximally separate the predefined groups of interest specified in the dataset [61][62][63]. It is similar to discriminant analysis, where datasets for n enterprises (here n = 43) and p ratios (here p = 10) are in the matrix Y = y 1,1 .…”