“…From 3600 to 3000 cm -1 the broad band corresponded to the characteristic stretching of O-H and N-H bonds (Božič et al, 2012b;Liu, You, Tarafder, Zou, & Fang 2019). It was possible to see two peaks on the curcumin spectrum, one at 3510 cm -1 and the other one at 1279 cm -1 corresponding to the stretching and the bending of the phenolic -OH groups, respectively (Božič et al, 2012b;Liu et al, Ying, Cai, & Le, 2017;Nascimento da Silva, de Matos Fonseca, Feldhaus, Soares, & Valencia, 2019). Peaks located at 1600 and 1508 cm -1 corresponded to the stretching of the C=C bonds of the cyclic alkenes (Božič et al, 2012b;Hasan et al, 2016;Poljanšek, Šebenik, & Krajnc 2006).…”