Rheological interactions between Lallemantia royleana seed extract and selected food hydrocolloids

BACKGROUND: Lallemantia royleana (Balangu) is a mucilaginous endemic plant which is grown in different regions of world. The flow behaviour of Balangu seed extract (BSE) and its mixture with xanthan, guar and locust bean gums at 1 : 3, 1 : 1 and 3 : 1 ratios, in addition to control samples (0% BSE), were evaluated. To describe the rheological properties of samples, the power law model was fitted on apparent viscosity-shear rate data. To evaluate the interaction between BSE and selected hydrocolloids in dilute solutions, the relative viscosity was also investigated. RESULTS: There was no significant difference between the consistency coefficient of guar and locust bean solutions and their blends substituted with 250 g kg(-1) BSE. The BSE-xanthan mixture at 1 : 3 and 1 : 1 ratios had consistency index equal to xanthan solution. BSE-locust bean gum at all ratios, BSE-xanthan at 1 : 3 ratio and BSE-guar gum at 1 : 1 and 3 : 1 ratios indicated relative viscosity lower than values calculated assuming no interaction. The intrinsic viscosity value of BSE was determined 3.50 dL g(-1). CONCLUSION: The apparent viscosities of BSE, selected hydrocolloids and their blends were the same at a shear rate of 293 s(-1) and the commercial gums can be substituted by 250 g kg(-1) and 500 g kg(-1) BSE. (C) 2011 Society of Chemical Industry