Enzymatic purification of Balangu seed (Lallemantia royleana) gum and evaluation of its physicochemical and emulsifying properties

Gums are long chain polysaccharides components with high molecular weight wildly used in the food and many other industries as stabilizer, texture modifier, gelling agent, thickener and emulsifier. The aim of this study was to investigation evaluation of physicochemical and emulsifying properties of protein-free balangu seed (Lallemantia royleana) gum. The results showed, balangu and protein-free balangu were obtained from molecular weight 3120 and 3360 kDa, respectively. Major functional groups were identified from FTIR spectrum of balangu and protein-free balangu, include O-H, C-H, C=O, -COO-, and C-O-C. The results of GC-MS showed that the major monosaccharides specified in Glucose, Galactose, Arabinose, Xylose and Rhamnose. According to the rheological protein-free balangu had the lowest protein content and this led to formation of large oil droplet size and lower emulsion stability. The parameters of Herschel–Bulkley model were showed, the values of coefficients of determinations (R2) were near to 1 and Root Mean Square Error (RMSE) values were lower than 0.4, which indicate the suitability of this model to describe the flow behaviour of samples. Moreover all emulsions represented flow behaviour index values less than 1, which reveals shear thinning behaviour of emulsions, but no significant difference was found between emulsions (p>0.05). On amplitude sweep test, the storage modulus values were greater than loss modulus values in all emulsions, which indicates their elastic behaviour. On frequency sweep test, the storage modulus values were greater than loss modulus values in all emulsions, which confirmed solid like behavior. The indices of power law’s storage modulus balangu and protein-free balangu emulsions had near to zero which reflect high elastic behaviour of emulsion.