Abstract:Objective This study aims to identify honey authenticity by terahertz (THz) spectroscopy.Method Different honey samples were analyzed by stable isotope ratio mass spectrometry (IRMS), and the results served as a reference for terahertz spectroscopy. The sample requirements and analytical conditions of terahertz spectroscopy were verified by comparing the results of these two methods.Result Liquid honey samples exhibited no discernible absorption peaks. However, significant differences in refractive index were observed among samples. The presence of water in liquid honey, particularly at high levels, affected the refractive index, potentially leading to misjudgment. After removal of water from liquid honey via freeze-drying, terahertz attenuated total reflection was employed for identification. The freeze-dried honey samples still showed no discernible absorption peaks but exhibited distinct refractive index variations, being grouped into two categories: one with minor refractive index fluctuations and average values ranging from 2.04 to 2.29, and the other with considerable fluctuations and average values ranging from 1.03 to 2.22.Conclusion Consistent results from both analytical methods demonstrate that terahertz spectroscopy can be employed for authenticity identification of honey samples.
