Variability Estimation of the Protein and Phenol Total Content in Honey Using Front Face Fluorescence Spectroscopy Coupled with MCR–ALS Analysis

Abstract

It has been explored to what extent the ratio of the two main fluorophores in honey, originating from proteins and phenolic compounds, change between the honey extraction stage and packaging in the jars. Fluorescence spectroscopy combined with multivariate curve resolution–alternating least squares (MCR–ALS) was used to determine the ratio of the spectral components originating from phenol and proteins (Ph/Pr)fl , as a ratiometric indicator of variability in selected Lime tree (Tilia L.) honey samples. Spectrophotometric quantification of phenols and proteins in the honey samples was also performed and their ratio (Ph/Pr)sp was calculated. The values of the (Ph/Pr)fl ratio and honey protein content after packaging depended on the quality of homogenization before packaging in jars. Colorimetric and fluorometric results for phenols and proteins were in compliance. The examples are the values 3.34, 3.30, and 9, 3.14 for (Ph/Pr)fl and corresponding values 2.64, 2.18, and 12.75, 2.31 for (Ph/Pr)sp, in all pairs, the first value presenting the sample after extraction and the second value the sample after packaging in jars. Both methods show that in the former case there is no change in the phenol/protein ratio, and in the latter case the ratio decreased.