Infrared measurements
Spectral data from all tomato juice samples were
collected in parallel using (1) a dry air purged benchtop
Excalibur Series 3100 Fourier-Transform infrared
spectrometer (Varian, now Agilent Technologies, Santa
Clara, CA) incorporating a KBr beamsplitter, DTGS
detector, and three reflection ZnSe ATR accessory;
(2) a handheld 4200 FlexScan FTIR spectrometer
(Agilent Technologies Inc., Danbury, CT), with a ZnSe
beamsplitter, DTGS detector and single-reflection
diamond ATR sampling interface. Both spectrometers
were operated at 4 cm-1 spectral resolution.