Optical Spectroscopic Analysis of Honey from Agro-Ecological Zones of Ghana

Abstract

This study investigated the optical spectroscopic properties of honey produced in Ghana's agro-ecological zones using Raman, Laser-Induced Fluorescence (LIF), and UV-Vis Transmission spectroscopic techniques. Various Multivariate Data Analysis (MDA) methods were applied to the spectroscopic data. UV-Vis Transmission and LIF spectroscopy identified phytochemical compounds, while Raman spectroscopy identified the sugar composition in the honey. The optical measurements revealed that honey types originating from the different agro-ecological zones did not necessarily possess the same spectral properties. The multivariate analysis revealed distinct groupings among the honey samples, where each group shared common constituents and exhibited unique qualities. These groupings were not determined by the agro-ecological zones, but rather by the spectral similarity relating to the specific properties and composition of the honey samples. Further, correlations were established between the LIF spectral parameters and physicochemical properties, including colour and 5-hydroxymethylfurfural (HMF) content, allowing for the prediction of honey freshness with high accuracy. The research also found specific excitation sources and sample pretreatment that effectively controlled fluorescence interference in the Raman spectral measurement of honey. Overall, the various analysis employed in this study has contributed to a better understanding of the optical spectroscopic properties of honey from the agro-ecological zones and their help for determining its phytochemical constituents and sugar composition. The study also offers potential applications for authentication, freshness prediction, and quality control that can be implemented for the honey industry in Ghana.