Quantitative Analysis of Individual Sugars during Starch Hydrolysis by FT-IR/ATR Spectrometry. Part II: Influence of External Factors and Wavelength Parameters

Abstract

Earlier experiments have confirmed the suitability of Fourier transform infrared attenuated total reflectance (FT-IR/ATR) spectroscopy for monitoring sugar production from starch hydrolysis. However, in order to confirm the suitability of this technique for an industrial use, the influence of external factors (proteins, salts, temperature) on the prediction, as well as the influence of wavelength parameters, must be evaluated. This paper shows that proteins and salts, which occur in low concentrations in sugar solution before purification, have virtually no influence on the detection of sugar. However, sample temperature, already a very important factor in the industrial hydrolysis of starch, does have an influence upon spectral measurements. This influence would therefore affect the prediction ability of a model made at a single temperature. A proven solution to the influence of temperature is to establish a model which takes into account the range of temperatures that occur during the hydrolysis process. Variations in wavelength parameters also have been shown to significantly affect prediction ability.