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United States Department of Agriculture

Agricultural Research Service

Title: The Effects of Temperature and Catalysis on the Thermochemical Degradation of Melezitose

item Gamble, Gary

Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 24, 2001
Publication Date: February 1, 2002

Interpretive Summary: Due to the impact of cotton stickiness on ginning and spinning processes, methods to detect cotton stickiness are of major importance to the cotton industry. Insect honeydews are the major source of cotton stickiness, and melezitose is one of the primary sugar components of these honeydews. It is therefore desirable to screen cotton for insect honeydew contamination based upon levels of melezitose. Currently, most cotton is screened following ginning, which requires elevated temperatures for optimal results. This work indicates that when subjected to heat at the gin, melezitose is substantially converted to other chemical species through a series of reactions, thus rendering it unusable as a measure of honeydew contamination.

Technical Abstract: Melezitose, a major constituent of aphid and whitefly honeydews, is subjected to different heating temperatures for varying time increments with varying amounts of malic acid, an organic acid catalyst. Products of the thermochemical degradation are investigated using high performance anion exchange chromatography (HPAEC) and UV-visible absorption spectroscopy. When heated without catalyst present, melezitose undergoes thermochemical degradation to form glucose and fructose as primary initial reaction products. Glucose and fructose subsequently degrade and ultimately form non-carbohydrate caramel polymers. The rate of the thermochemical degradation is accelerated both by increasing reaction temperature and by the addition of a small amount of malic acid as a catalyst.

Last Modified: 3/29/2015
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