Xylitol

Description

Xylitol is a sugar substitute of the group of sugar alcohols and occurs naturally in many plants. Its sweetening power and flavour approach those of saccharose. In the human body, xylitol accumulates as an intermediate product in the metabolism of glucose.

• Since xylitol cannot be utilized by bacteria that are involved in the formation of dental cavities, it is used for example in sugar-free chewing gum and other products that are beneficial to teeth.
• Xylitol evokes a feeling of coolness on the tongue and so may be used to support the "fresh" tastes and flavours, e.g. of menthol.
• Since xylitol does not react with amino acids present in food, browning reactions during baking and frying can be avoided by the application of xylitol.
• Sugar substitutes such as xylitol are partly absorbed by the small intestine and subsequently are absorbed unaltered into the large intestine, where they bind water. In cases of increased absorption, this may lead to diarrhoea.

Application

The main use for xylitol is in calorie-reduced or sugar-free foods such as:

• desserts, ice ceam
• jam, bread spreads, fruit preparations
• chewing gum, confectionaries
• baking goods
• instant sauces, mustard

Gene technology

Traditionally, xylitol is produced chemically from wood sugar (xylose), which is available from wood chips produced in the paper industry. Xylose occurs in the tissue of many plants, such as birchwood, straw, corncobs and coconuts.

Additionally,glucose can be the base material for the production of xylitol. This develops in the process of starch saccharification of plant starch.

• If glucose is won from maize or maize starch it may consist partly of genetically modified maize, especially when the raw materials are imported from the USA or Argentina. In the EU, genetically modified maize is grown on a comparatively small area and nonetheless is not used as raw material for foodstuff. This may change in the case that the cultivation of GM maize increases in significance.
• Enzymes solubilise plant starch and metabolise it into compounds classified as ingredients and additives. Several such enzymes, such as amylases, glucose-isomerase and pullulanase, are produced with help of GM-microorganisms.

In the USA, a procedure has been developed to produce xylitol with help of GM microorganisms (Escherichia coli). The bacteria was altered in order to solubilise particular forms of plant cellulose (the structural substance of plant cells) and can produce xylitol. There is no information on the prospective commercial use of this procedure.

Labelling: starch-based additives are subject to labelling if they are directly produced from genetically modified plants (e.g. maize). It is not yet explicitily clarified whether this also applies to xylitol that results from starch and glucose respectively by way of various processing stages. In practice, it has been established that labelling is not applied.

Enzymes and their manner of production generally are not declared on the list of ingredients.

Additives that are produced in closed systems with the help of GM microorganisms are not subject to a labelling requirement, provided that the additive in question has been purified and does not contain any microorganisms.

An additive is not subject to a labelling requirement even on the case that the microorganisms used in its production have obtained nutrients (substrates) derived from GM plants.