Writing in Food Research International, Avishek Majumder and Arun Goyal from the Indian Institute of Technology Guwahati report that glucan produced by the bacterial strain Leuconostoc dextranicum NRRL B-1146 may thicken solutions at low concentrations.
“The advantages of this specific type of glucan can be in the sourdoughs in bakery applications as more water can be bound in the dough, as glucan is a hydrocolloid, it can bind high amounts of water,” wrote Majumder and Goyal.
“Glucan improves dough stability and gas retention through a structure build up of the glucans and interaction with gluten network,” they added.
Gelling agents fall under the hydrocolloids umbrella - ingredients used extensively by the food industry to texturise and stabilise food products from dressings to ice cream. Though these products are sensitive to spiralling raw material costs, the demand for hydrocolloids remains impressive.
The food industry's most frequently used hydrocolloids include: agar, alginates, arabic, carrageenan, Carboxy Methyl Cellulose (CMC), gelatin, konjac flour, locust bean gum (LBG), Methyl Cellulose and hydroxypropyl Methyl Cellulose (MC/HPMC), microcrystalline cellulose (MCC), pectin, starch and Xanthan.
Majumder and Goyal produced using L. dextranicum NRRL B-1146 obtained from the USDA’s Agricultural Research Service Culture Collection. The glucan was purified to remove other traces of polysaccharides and proteins. A semi-dilute solution of the glucan was produced for rheological measurements, including viscosity and shear stress.
Scanning electron microscopy of the glucan showed a porous or web-like structure with excellent water holding capacity due to the small pore size distribution, said the researchers.
“This relatively new biopolymer has unique rheological properties because of its potential of forming very viscous solutions at low concentrations and pseudoplastic nature and can be used as thickening or gelling agent in food,” they wrote.
“This glucan can be used as thickening or gelling agent in food or in the sourdoughs in bakery applications,” they concluded.
With a distinct aroma and flavour, sourdoughs are traditionally produced through a lengthy fermentation process, which has become incompatible with the fast pace of commercial bread production.
Dr Majumder is currently affiliated with the Enzyme and Protein Chemistry Group at the Technical University of Denmark.
Source: Food Research International
May 2009, Volume 42, Issue 4, Pages 525-528
“Rheological and gelling properties of a novel glucan from Leuconostoc dextranicum NRRL B-1146”
Authors: A. Majumder, A. Goyal