Comprehensive study of intrinsic viscosity, steady and oscillatory shear rheology of Barhang seed hydrocolloid in aqueous dispersions

Barhang seed (Plantago major seed [PMS]) is rich of gum and can be potentially used as a new hydrocolloid in foodstuffs for different purposes. Rheological behaviors of hydrocolloids are the most important features of them in food applications. For this reason, the different rheological behaviors of the PMS gum in aqueous solutions were determined. The PMS gum solutions showed shear thinning and thixotropic behaviors depend on concentrations. The resulted data from steady shear flow tests demonstrated that the stress–shear rate, apparent viscosity–shear rate, and stress–time data were well fitted in Herschel–Bulkley, Carraeu, and Figuni–Shoemaker models with high R² and lower RMSE values. In strain and frequency sweep experiments, the PMS solutions with 0.1 and 0.5% wt/vol concentration indicated viscous-like behavior which related to lack of strong interactions in the structure however, the samples with 1 and 2% wt/vol showed gel-like behavior which was attributed to more stable interactions between polysaccharide chains. Intrinsic viscosity of this hydrocolloid was in the range of 19.211–19.683 dL/g, which indicates random coil structure of PMS gum in solution.

Practical applications

The most important functional property of hydrocolloids is thickening features, which are related to their ability in enhancing of viscosity and formation of gel structure at relatively low concentration. Thickening and viscoelastic properties of hydrocolloids have critical role in consumer acceptance and stability of different food products such as fruit juices, sauces, ready jells, and desserts. Hence, identification and determination of properties of new food hydrocolloids are interested in food industries.