As high maize prices continue to stoke fears about food price inflation, slimmers and those on a gluten-free diet could soon be hit by price increases as the cost of xanthan gum is going up.
Xanthan gum is widely used as a thickening agent and substitute for egg whites in products such as salad dressings, sauces and fillings, and it is often added to low-fat or no-fat dairy products to improve mouthfeel.
It can also be used for making gluten-free foods, as xanthan gum can increase the binding strength of gluten-free flour.
Xanthan is generally derived through the fermentation of the glucose in maize syrup, making it highly vulnerable to any increases in the cost of maize on the global commodity markets. Fierce competition between producers in 2008/9 made xanthan gum very cheap, but prices in China – the world's largest producer – have now increased by 25% to £3,237/tonne year-on-year.
It's not just soaring maize prices as a result of the US drought that are to blame. Xanthan gum is increasingly being used as a cheaper alternative to guar gum in many foods, and by the oil industry, to thicken drilling mud.
Guar prices recently fell on the expectation of a good Indian guar crop in November, but if global demand for guar continues to outstrip the supply, traditional users of guar gum – also from the food industry – are expected to increasingly look for alternative thickeners or gel forming compounds such as xanthan gum.
Demand for guar and xanthan from the oil exploration sector is tipped to remain strong – and maize prices are expected to stay high for months to come – putting further pressure on many slimmers' favourites on UK supermarket shelves.
Natural gums are polysaccharides of natural origin, capable of causing a large viscosity increase in solution, even at small concentrations. In the food industry they are used as thickening agents, gelling agents, emulsifying agents, and stabilizers. In other industries, they are also used as adhesives, binding agents, crystan inhibitors, clarifying agents, encapsulating agents, flocculating agents, swelling agents, foam stabilizers, etc. Most often these gums are found in the woody elements of plants or in seed coatings.
Natural gums can be classified according to their origin. They can also be classified as uncharged or ionic polymers (polyelectrolytes). Examples include (E number food additive code):
- Natural gums obtained from seaweeds:
- Agar (E406);
- Alginic acid (E400) and Sodium alginate (E401);
- Carrageenan (E407);
- Natural gums obtained from non-marine botanical resources:
- Gum arabic (E414), from the sap of Acacia trees
- Gum tragacanth (E413), from the sap of Astragalus shrubs
- Karaya gum (E416), from the sap of Sterculia trees
- Guar gum (E412), from guar beans
- Locust bean gum (E410), from the seeds of the carob tree
- Beta-glucan, from oat or barley bran
- Glucomannan (E425), from the konjac plant
- Tara gum (E417), from the seeds of the tara tree
- Natural gums produced by bacterial fermentation:
For example, xanthan gum is a polysaccharide, derived from the bacterial coat of Xanthomonas campestris, used as a food additive and rheology modifier, commonly used as a food thickening agent (in salad dressings, for example) and a stabilizer (in cosmetic products, for example, to prevent ingredients from separating). It is produced by the fermentation of glucose, sucrose, or lactose by the Xanthomonas campestris bacterium. After a fermentation period, the polysaccharide is precipitated from a growth medium with isopropyl alcohol, dried, and ground into a fine powder. Later, it is added to a liquid medium to form the gum.
Xanthan is generally derived through the fermentation of the glucose in maize syrup and is very popular in foods for coeliacs where wheat cannot be used and other cereals have to be used to form stable doughs
Gums, such as tragacanth and gum arabic (acacia gum) are obtained by ‘milking trees’ and plants for their sap. They tend to be flavourless and along with other thickening and gelling agents such as agar and pectin, they have been used for some time in vegetarian diets, for instance to produce mayonnaises.
The importance of these compounds both to exporting countries and the industries dependent on them is highlighted by their featuring in a number of political battles.
For instance, Sudan is the world's largest single producer of gum Arabic and hundreds of thousands of poor Sudanese are dependent on gum arabic for their livelihoods. In a press conference held at the Washington Press Club in May 2007, John Ukec Lueth Ukec, Sudan's ambassador to the United States, threatened to stop exportation of gum arabic from his country if sanctions were imposed on Sudan. He made his speech surrounded by Coca-Cola products, although other sodas use acacia gum as an emulsifier, as well.