Lead researcher Sylvie Turgeon told FoodNavigator.com that the result has implications for the food industry, and could lead to "better stabilisation of products, optimisation of food formulation, and improvement of quality," for food products ranging from dressings to ice creams.
Xanthan gum is said to be one of the only exceptions in avoiding the price rises being experienced by many hydrocolloids. Rising energy, raw material and transportation costs have seen the cost of nearly all hydrocolloids increase in the last year according to hydrocolloid information service IMR's Quarterly Review.
The research, published on-line ahead of print in the journal Food Hydrocolloids (doi: 10.1016/j.foodhyd.2006.03.005), sought to deepen understanding of how proteins and polysaccharides to allow for a more optimal use of mixed proteinpolysaccharide systems in food formulation.
Researchers Marie-Eve Bertrand and Turgeon from the University of Laval in Canada looked at the effect of pH, salt content, and xanthan gum concentration on the gelling of whey protein isolate (WPI), an extensively studied and functionally excellent protein.
"In general when mixing a polysaccharide with proteins there are different cases that could be experienced: attractive or segregative conditions that could either lead to stability or instability," explained Turgeon. "Here we were interested by the possible use of smaller quantities of xanthan to obtain substantial texture improvement."
Three different pH levels were assessed - 6.5, 6.0 and 5.5 - along with three different levels of xanthan gum (purchased from Kelco Co.) - 0.01, 0.03 and 0.06 per cent - and two different NaCl levels (100 and 500 mM) on the formation of whey protein isolate (Bipro, purchased from Davisco Food International)xanthan gum gels.
Bertrand and Turgeon report that a synergistic effect on the strength of the gel was observed at both pH 6.5 and 6.0 for all the xanthan gum concentrations studied, but an antagonistic effect was observed at the lower pH.
Indeed, addition of 0.06 per cent xanthan gum is reported to have increased the so-called elasticity modulus, a measure of gel strength, by two-fold at pH 6.0, while at pH 6.5, the gel strength increased by almost four-fold.
The research, funded by the Canadian Natural Sciences and Engineering Research Council (NSERC), also found that salt concentrations had both beneficial and detrimental effects on the strength of the resultant gel, and was dependent on both pH and xanthan gum levels.
"We recently filed a patent on the use of these interactions to obtain a gel from native proteins in mixture with polysaccharides but the concentrations are well below what was usually reported to obtain a gel (for example, 0.1 to 1 per cent) in total solid," Turgeon told FoodNavigator.com.
"We are still studying these systems as they are probably the answer to the synergistic effect of exopolysaccharide-producing strains in yogurt," she said.
In the United States and in Europe, both xanthonomas and gelling polymers are authorised for use in the food industry. Xanthonomas (E-415) is the most common, and has become the centre of a thriving industry.
Gelling polymers have plenty applications in the food industry, such as water-based gels complementation gel, confectionery, compotes and jams, cake and pudding fillings, pre-cooked meals and dairy products.