. 2019 Jun 10;9:8375. doi: 10.1038/s41598-019-44807-x

Table 2.

Location and assignment of the peaks identified in FTIR spectra for the five different edible films.

Region	Peak wavenumber (cm⁻¹)					Assignment and remarks
Region	GC-C	GC-DC	GC-E	GC-DE	GC-DTE	Assignment and remarks
Amide A	3432	3416	3432	3424	3409	N–H stretch coupled with hydrogen bond
Amide B	2914	2914	2922	2922	2929	CH antisymmetric and symmetric stretching
Amide B	2847	2847	2847	2840	2876	CH antisymmetric and symmetric stretching
Amide I	1738	1745	1656	1656	1648	C=O stretch/hydrogen bond coupled COO⁻
Amide II	1603	1595	1544	1544	1551	NH bend coupled with CN stretch
	—	—	1453	1438	1446	CH₂ bending (scissors) vibration
	1378	1386	1378	1378	1394	CH₂ wag of proline and glycine
Amide III	—	—	1229	1229	1236	NH bend stretch coupled C–N stretch
Fingerprint	1102	1102	1027	1027	1042	C–O skeletal stretch
	—	—	929	929	929	C-H deformation vibration (carbohydrate)
	—	—	861	854	854	C–H deformation vibration (carbohydrate)
	675	667	659	667	667	C–C Skeletal stretch