Table 4.

Assignment of some bands of CAMB after freeze drying and after storage (cm⁻¹)

Assignment of functional group	Frequency (cm−1) in:
	CAMB after FD	CAMB (aw, 0.07)	CAMB (aw, 0.1)	CAMB (aw, 0.2)	CAMB in aluminum foil
PO symmetric stretching	1,043.6 ± 0.5	1,043.8 ± 0.2	1,042.3 ± 0.3	1,043.2 ± 0.3	1,047.4 ± 0.4
PO asymmetric stretching	1,218.5 ± 0.5	1,226.5 ± 0.5	1,225.2 ± 0.3	1,226.2 ± 0.3	1,227.2 ± 0.3
N+(CH3)3 asymmetric stretching	978.2 ± 0.3	979.8 ± 0.3	983.8 ± 0.3	994.7 ± 0.3	995.9 ± 0.2
CH2 symmetric stretching	2,867.4 ± 0.1	2,854.3 ± 0.6	2,855.5 ± 0.5	2,853.2 ± 0.3	2,849.0 ± 0.0
CH2 asymmetric stretching	2,923.3 ± 0.2	2,920.7 ± 0.6	2,921.5 ± 0.6	2,920.7 ± 0.6	2,931.5 ± 0.5
Amide II	1,536.4 ± 0.4	1,534.5 ± 0.5	1,537.8 ± 0.3	1,536.5 ± 0.5	1,529.8 ± 0.3 and 1,515 ± 0.1