Innovative glucan may be useful as food thickener, suggests study
The research, published in Food Hydrocolloids, investigated the rheological properties of Salecan, a novel soluble glucan produced by Agrobacterium sp. ZX09.
The authors noted that the microbial polysaccharide produces good thickening even in small quantities, and is stable under a number of physical conditions including a wide ranges of temperatures and pH values.
“All data indicated that Salecan has excellent rheological properties and could be utilized in food industry as a new source of thickening agent,” wrote the authors, led by Jianfa Zhang, from the center for molecular metabolism at the Nanjing University of Science & Technology, China.
Thickening agent
Polysaccharides are widely used in the food industry due to their ability to modify the rheological and functional properties of food systems.
“Starch, one of the most important functional food biopolymers, is added to many products including a variety of low-fat products as a functional ingredient to improve their rheological characters,” said Zhang and colleagues.
They noted that polysaccharides of microbial origin have been developed as source of additives for several industries. These include xanthan from Xanthomonas campestris, Succinoglycan from Sinorhizobium or Agrobacterium and gellan from Pseudomona elodea .
“Polysaccharides from microbial sources are in particular used as the food additive because they also have the advantage of being regarded as totally natural for many consumers,” explained the authors.
The microbe Agrobacterium sp. ZX09 has been shown to synthesise high volumes of an extracellular polysaccharide named Salecan, a novel soluble glucan.
Zhang and co-workers evaluated the rheological behaviour of Salecan in solution, as a new source of hydrocolloid gum used in food.
Study details
Zhang and colleagues observed that increasing concentrations increased the viscosity and pseudoplasticity of the resulting mixture.
They noted that temperature “had relatively little effect on the viscosity” below 55 °C, adding that flow behaviour also remained stable after freezing.
pH was found to have almost has no influence on apparent viscosity of Salecan solutions between 6.0 and 12.0.
Dynamic measurements also suggested that elastic behaviour dominates over the viscous component throughout the entire frequency range examined.
“It can be seen that Salecan may be utilized in foods to give viscosity, body, and mouth feel as a new source of thickening agent,” said Zhang and co-workers.
They added that only a small quantity of Salecan could produce a marked shear thinning, concluding that Salecan “will be more appropriate to use as food additive compared with many other polymers.”
Source: Food Hydrocolloids
Published online ahead of print, doi: doi:10.1016/j.foodhyd.2011.03.013
“Rheological properties of Salecan as a new source of thickening agent”
Authors: A. Xiu, M. Zhou, B. Zhu, S. Wang, J. Zhang
