2.5. Fourier Transform Infrared (FTIR) Spectroscopy

The short-range molecular order of starch samples was determined using a FTIR spectrometer (Tensor 27, Bruker Opticals Company, Rheinstetten, Germany). FTIR spectra were recorded from 4000 to 600 cm⁻¹ at a resolution of 4 cm⁻¹ with an accumulation of 64 scans using the attenuated total reflectance (ATR) accessory. All spectra were baseline corrected automatically by OMNIC 8.2 and deconvoluted from 1200 to 800 cm⁻¹ with a half-bandwidth of 19 cm⁻¹ and an enhancement factor of 1.9. Intensity measurements were performed on the deconvoluted spectra by recording the peak height of absorbance bands from the baseline. The ratio of absorbance at 1047/1022 cm⁻¹ and 1022/995 cm⁻¹ was used to estimate the short-range ordered structure of starch [6,24].