TILIA HONEY’S FRUCTOSE, GLUCOSE AND SUCROSE CONTENT PREDICTION USING FT-IR SPECTRA WITH PARTIAL LEAST SQUARES REGRESSION

The aim of this study was to assess the usefulness of Fourier transform infrared (FT-IR) spectroscopy coupled with partial least squares regression (PLS-R) to predict the fructose, glucose and sucrose content of tilia honeys. In order to achieve the aim of this study, 22 samples of tilia honey were purchased from Suceava, Neamt and Iasi County in the year of 2020. The fructose, glucose and sucrose content was determined prior the PLS-R prediction using high-performance liquid chromatography coupled with refractive index detector (HPLC-RID). The fructose content of tilia honeys ranged from 31.94 to 35.22%, the glucose content ranged between 26.76 and 33.15%, while sucrose content ranged between 0 and 2.20%. For the prediction of fructose, glucose and sucrose it was used the 3000 - 2800 + 1700 - 1600 +1540 -700 cm-1 spectral range. The spectral data was submitted to different mathematical pretreatments in order to reduce the noise and to improve the prediction of results. For the prediction of fructose content the suitable pretreatment was Multiplicative Scatter Correction – MSC, for glucose prediction the suitable pretreatment was Standard Normal Variate – SNV, while for the prediction of sucrose the suitable pretreatment was 1st derivate.