An evaluation of FTIR spectroscopy for prediction of royal jelly content in hive products

In this work, a rapid FTIR-ATR spectroscopic method combined with chemometrics was developed to predict royal jelly content in hive products; namely, dietary supplements such as royal jelly, propolis, honey and pollen. FTIR spectra of royal jelly, propolis, honey and pollen as well as their mixtures and dietary supplements were characterized. Amide II spectral absorption band with a peak point around 1547 cm(-1) in the spectral range 1580-1500 cm(-1) was used for quantitative estimation based on the calibration method using Partial Least Squares Regression (PLSR) and principal component regression (PCR) analyses. The results from the developed FTIR technique were also validated by those from HPLC-PDA technique, revealing a good correlation between FTIR and HPLC results (R-2 = 0.99). The results of the present study suggest that the developed FTIR spectroscopy technique can be used to rapidly, easily and accurately predict the royal jelly content in the hive products.