The F. thunbergii flour was mixed and ground with KBr in a weight ratio of 1:100. Then, 60 mg of the mixture was pressed into a tablet. The Fourier transform infrared (FT-IR) spectra were recorded using a Tensor 27 spectrometer (Bruker , Germany), and the absorbance spectra were collected between4000 and 400 cm−1at a resolution of 4 cm−1and 64 scans. The obtained spectra were smoothed, and the baseline was corrected using OPUS software and exported as dpt files to Origin8.5 software (Origin Lab) to create graphs.