2.6.2. Instrumental FT-IR Method

In this methodology, the FT-IR spectra recorded for the characterization of pectins were used to determine the degree of methoxylation (DM), taking into account the band areas at 1747–1746 cm−<sup>1</sup> and 1633–1621 cm−<sup>1</sup> arising from methyl-esterified and carboxylate groups, respectively. The degree of methoxylation was obtained using the equation:

$$\% \text{DM} = [\text{A COOCH}\_3 / (\text{A COCH}\_3 + \text{ACCO}^-)] \times 100$$
