Optical absorption characteristics of corn oil were investigated in th
e visible and near infrared regions between 400 and 2500 nm as the oil
degraded during potato frying. The visible wavelength of maximum abso
rption between 400 and 600 nm shifted towards longer wavelengths as th
e frying operation progressed. The results showed that light absorptio
n in the visible range of the electromagnetic spectrum between 400 and
600 nm correlated well with viscosity.