Noninvasive method for monitoring ethanol in fermentation processes using fiber-optic near-infrared spectroscopy

Journal Article · Sat Sep 15 00:00:00 EDT 1990 · Analytical Chemistry (Washington); (USA)

DOI:https://doi.org/10.1021/ac00217a015· OSTI ID:6195912

Cavinato, A G; Mayes, D M; Ge, Z H; Callis, J B ^[1]

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1. Univ. of Washington, Seattle (USA)

Short-wavelength near-infrared (SW-near-IR) spectroscopy (700-1100 nm) is used for the determination of ethanol during the time course of a fermentation. Measurements are performed noninvasively by means of a photodiode array spectrometer equipped with a fiber-optic probe placed on the outside of the glass-wall fermentation vessel. Pure ethanol/water and ethanol/yeast/water mixtures are studied to establish the spectral features that characterize ethanol and to show that determination of ethanol is independent of the yeast concentration. Analysis of the second-derivative data is accomplished with multilinear regression (MLR). The standard error of prediction (SEP) of ethanol in ethanol/water solutions is approximately 0.2% over a range of 0-15%; the SEP of ethanol in ethanol/yeast/water solutions is 0.27% (w/w). Results from the mixture experiments are then applied to actual yeast fermentations of glucose to ethanol. By use of a gas chromatographic method for validation, a good correlation is found between the intensity of backscattered light at 905 nm and the actual ethanol. Additional experiments show that a calibration model created for one fermentation can be used to predict ethanol production during the time course of others with a prediction error of 0.4%.

• OSTI ID: 6195912
• Journal Information: Analytical Chemistry (Washington); (USA), Vol. 62:18; ISSN 0003-2700
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ETHANOL
YIELDS
GLUCOSE
FERMENTATION
BIOREACTORS
DATA COVARIANCES
FORECASTING
GAS CHROMATOGRAPHY
INFRARED SPECTRA
INFRARED SPECTROMETERS
MATHEMATICAL MODELS
YEASTS
ALCOHOLS
ALDEHYDES
BIOCONVERSION
CARBOHYDRATES
CHROMATOGRAPHY
EUMYCOTA
FUNGI
HEXOSES
HYDROXY COMPOUNDS
MEASURING INSTRUMENTS
MICROORGANISMS
MONOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
SACCHARIDES
SEPARATION PROCESSES
SPECTRA
SPECTROMETERS
090900* - Biomass Fuels- Processing- (1990-)