*3.1.3 Infrared Fourier transform analysis*

As shown in **Figure 2** and **Table 5**, the IRTF analysis of cocoa hulls powder shows different peak intensities.

Five main groups of adsorption bands emerge, namely those between 3000–3500, 3000–2500, 2000–1500, 1000–500 cm−1. The wavenumber bands between 3000 cm−1 and 3500 cm−1 is attributed to the vibration of elongation of the linked alcohol OH group. The wavenumber between 2500 cm−1 and 3000 cm−1 shows the presence of the CH elongation bond. The adsorption band between 2000 cm−1 and 1400 cm−1 is the characteristic of CO elongation. The absorption band of 1000 cm−1 corresponds to the CC bond.
