Kinetics of dextrose degradation under autoclaving conditions

Abstract

The kinetics of the decomposition of dextrose have been investigated over a temperature range of 106" to 127". The reaction is shown to exhibit an induction period with respect to 5-hydroxymethylfurfural production which is due to the formation of an intermediate compound. A reaction mechanism is proposed which appears consistent with the experimental measurements. Rate constants are calculated for the various reaction steps and the activation energies associated with these steps are reported.Dextrose decomposes under autoclaving conditions, one of the main decomposition products being 5-hydroxymethylfurfural (5-HMF).The kinetics of this decomposition have been extensively studied usually by measuring the rate of dextrose depletion or the rate of 5-HMF production. Most investigators have equated these rates. The rate of the decomposition reaction is relatively small and previous workers have accelerated the decomposition by working in solutions of fairly high acid concentration. These measurements have, in general, shown that the reaction is first order in dextrose concentration and that it is catalysed by hydrogen ion. Kinetic treatment of the decomposition has been made on a reaction mechanism represented by Dextrose -+ 5-HMF -+ Products The products of the second step in the reaction have been assumed to be formic and laevulinic acids.It has been shown (Wolfram, Schuetz & Cavalieri, 1948) on the basis of spectroscopic evidence that there is an intermediate compound produced during the formation of 5-HMF from dextrose. These observations would appear to indicate that, under conditions of autoclaving, fairly neutral solutions of dextrose decompose according to a mechanism Dextrose -+ Intermediate -+ 5-HMF -+ ProductsThe purpose of the present investigation was to study the effect of changes in dextrose concentration, temperature and pH on the kinetics of dextrose decomposition actually encountered during autoclaving and to determine if the mechanism is adequately represented by either of the above schemes. The interest in such a reaction lies in the concentration of the various decomposition products arising as a function of time rather than the concentration of dextrose decomposed.t Present address, Western General Hospital, Edinburgh, U.K.

HPLC Studies on the Degradation Profiles of Glucose 5% Solutions Subjected to Heat Sterilization in a Microprocessor-Controlled Autoclave

“…Sample degradation procedures. Glucose degradation by heat has been well documented, and is generally accepted to follow pseudo-zero (lo), or first order (8,9) kinetics. T h e major degradation product, 5-HMF, is formed through intermediates, as yet unidentified.…”

Formaldehyde scavenging from peritoneal dialysis solutions using reduced aminothiol compounds

“…Both low and higher molecular weight aldehydes are generated from glucose degradation after the heat sterilization procedure during the manufacture of the solutions. [1][2][3][4][5][6] Aldehydes have also been discovered in freezing solutions, caused by the autoxidation of the cryoprotective compounds. 7 In vitro studies have demonstrated that aldehyde toxicity diminished the viability of frozen mouse oocytes and zygotes; as well as fibroblasts and peritoneal mesothelial cells in culture.…”

High Glucose Induces a Hypertrophic, Senescent Mesothelial Cell Phenotype after Long in vivo Exposure

“…Before use, samples were analyzed for the presence of intermediate products of the nonenzymatic degradation of glucose at wavelengths of 228 and 284 nm, using a UV-1202 UV-vis Spectrophotometer (Shimazu, Kyoto, Japan) [14]. Under these conditions, the glucose-enriched, filter-sterilized solution did not show absorption.…”