2.4.6. Fourier Transform Infrared (FTIR) Analysis
The FTIR analysis was conducted at the Center for Grain and Animal
Health Research (USDA-ARS, Manhattan, KS, USA). Attenuated total
reflectance (ATR)-FTIR spectra collected at 400–4000
cm-1 range with a resolution of 4
cm-1, data spacing of 0.482 cm-1,
and 32 scans using a Thermo Nicolet iS50 FTIR (Thermo Fisher Scientific
Co., Waltham, MA) spectrometer equipped with a single-bounce diamond
crystal and a deuterated triglycine sulfate detector. Measurements were
repeated twice for each sample at ambient temperature. The quantitative
analysis was done by “peak fitting” procedure and individual component
bands according to a Gaussian curve fit (GRAMS/AI™ Spectroscopy Software
Suite, Thermo Scientific™, Waltham, MA, USA).