And the applications for corn fibre gum beyond beverages could possibly include encapsulation of essential oils and fatty acids, glossy coatings and biodegradable edible films, and even as a prebiotics, lead researcher Dr. Madhav Yadav from the USDAs Agricultural Research Service told FoodNavigator.com.
The supply of gum arabic (E414 in the EU), also known as acacia gum because it comes from Acacia trees in the gum belt of Africa, is variable due to political and climatic factors in the primary producing countries like Sudan and Nigeria and this has led to spikes in the price of the ingredient.
Gum arabic, known as the Rolls Royce' of gums, is widely used by the food and beverage industry, and the top producers (mainly Sudan) bring about 50,000 tonnes of the gum to the market each year.
Attempts to find an alternative have lead researchers, particularly in the US, to look into the use of corn fibre, a readily available and low valued by-product of corn milling, to produce a gum that could be used as a thickener, adhesive, and stabiliser for food and beverage applications.
"Based on my research in the laboratory conditions, [corn fibre gums] usage level for oil-in water emulsion system without any added additive is very low, which will significantly decrease the cost to make beverage," said Dr. Yadav from the ARS Eastern Regional Research Center in Pennsylvania.
In a research article, published on-line ahead of print in the journal Food Hydrocolloids (doi: 10.1016/j.foodhyd.2006.07.009), Dr. Yadav and his co-workers prepared corn fibre gums from two different types of corn fibre: one from ADM Research, Bunge, and one from Cargill Central Research.
The gums were prepared by a sequential alkaline extraction and alkaline hydrogen peroxide bleaching technique or an additional alkaline hydrogen peroxide treatment of the alkali treated residue. These were compared with a commercially available industrial grade gum, provided by National Starch, and also with native and modified gum arabic (from TIC gums).
Citrus oil-in-water emulsions were prepared for each of the gums and the emulsifying properties and stability evaluated.
"Their stabilities were better than native arabic gum and superior or equal to modified gum arabic after 7 and 14 days," wrote Yadav.
"It has a unique combination of excellent emulsifying properties and low solution viscosity despite its high molecular mass," he said.
While Dr. Yadav could not comment on the price of commercial corn fibre gum, he told FoodNavigator.com that a rough cost estimation by an ARS cost engineer suggested that, based on the assumed price of the raw materials, the cost would be about $2.00 per pound ($4.40 per kg) for a laboratory preparation. This compares favourably with the time market value of gum arabic, that was between $3.00 and $6.00 per pound ($6.60 to $13.20 per kg), said Dr. Yadav.
But the cost of the individual ingredient may not be the only benefit, he said, because corn fibre gum could reduce or even eliminate the need for weighting agents, such as brominated vegetable oil (BVO), sucrose acetate isobutyrate (SAIB), ester gum, and damar gum, that are used to increase the specific gravity of oil to match aqueous phase density, and therefore stabilise flavour oils and/or clouding oils in the beverages.
These additives are not always acceptable to consumers, said Dr. Yadav, with many countries expressing concern about the possibility of bromine storage in the body when BVO is included in food. This, he said, has lead the United States government to impose a limit of BVO to 15 ppm in the finished beverage.
"Thus the development of a technology to formulate a physically stable oil/water beverage emulsions without using any weighting agents looks beneficial."
But while the laboratory results and cost estimations offer significant promise, Dr. Yadav confirmed that the biggest challenge for corn fibre gums remained "being able to produce CFG cost-effectively in a form that will meet the demands of the end user in product applications."