ISSN:
0884-3996
Keywords:
cereal products
;
auto-oxidation
;
hydration
;
chemiluminescence spectra
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Spectra of ultraweak chemiluminescence (CL) accompanying auto-oxidation and hydration of cereal products have been measured using single photon counting and cut-off filters. The spectra cover the 380-880 nm spectral range with maxima centred around 600 nm. Analytically pure air-dried carbohydrates like agar, cellulose and nitrocellulose give emission too weak for spectral measurements. The emission from water pure carbohydrates is on average 4-12 times higher and emission spectra are similar to those from cereal products. The effect of free radical scavengers, SOD and O*2 (1Δg)-quenchers on CL spectra indicates a contribution of radical reactions with the participation of excited carbonyls, O2- and excited molecular oxygen dimoles. Moreover, possible mechanisms of chemi-excitation due to a cooperative H-bond formation during the hydration of carbohydrates and/or recombination of trapped radicals and electron-holes are discussed. It is also postulated that the excitation energy transfer to natural sensitizers occuring in cereal products may account for non-specific broad spectra and differences in the intensity of CL. © 1998 John Wiley & Sons, Ltd.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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