ISSN:
0884-3996
Keywords:
chemiluminescence
;
cereal products
;
auto-oxidation
;
hydration
;
weak molecular interactions
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Addition of water to cereal grains and food products such as flour, bread and crackers stimulates ultraweak chemiluminescence, the intensity of which depends upon cereal species, its origin and history, grinding, time after grinding, initial moisture content, solvent, temperature and additives. Pure carbohydrates (e.g. dextran) display much weaker and shorter chemiluminescence. A low activation energy (25 kJ/mol) in the temperature range of 20-40°C, Van't Hoff coefficient of 1.4 and the diminution of chemiluminescence output in ethanol and acetone vs. water suggest that weak molecular interactions, e.g. hydrogen bond scission or formation, determine the rate-limiting steps of chemi-excitation. The emission decay kinetics fit a hyperbolic function rather than an exponential one, thus suggesting a contribution of the recombination-luminescence of ions and free radicals to the mechanism. The results appear to demonstrate a significant role of weak interactions of the water-carbohydrates systems in processes leading to electronic excitation and chemiluminescence. © 1997 John Wiley & Sons, Ltd.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
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