Xanthan-locust bean gum interactions and gelation

• Published in: Carbohydrate polymers Vol. 21; no. 1; pp. 53 - 58
• Main Authors: Zhan, D.F., Ridout, M.J., Brownsey, G.J., Morris, V.J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1993; Elsevier Science
• Subjects: Applied sciences; Biological and medical sciences; Exact sciences and technology; Food additives; Food industries; Fundamental and applied biological sciences. Psychology; gelation; General aspects; gums; interactions; ionic strength; melting point; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; temperature; xanthan gum; Property composition relationship; Carob gum; Gelation; Physical gel; Experimental study; Mechanism; Mixture; Gelling agent; Helix coil transition; Ionic strength; Oside polymer; Aqueous solution; Melting point; Saline solution
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/0144-8617(93)90117-M

The gelation of xanthan-locust bean gum (LBG) mixtures has been investigated. It has been observed that, over the ionic strength range chosen, the melting temperatures of the gels ( T g) remains constant, whereas the order-disorder transition temperature ( T m) for xanthan alone increases with increasing ionic strength. The preparation temperature ( T p) of the mixed gels is known to affect gelation. Studies have been made on the effect of T p relative to T g and T m on gelation. It has been observed that gelation occurs at all T p, even when T p < T m. At a given ionic strength, increasing T p leads to an increase in the measured storage modulus ( G′) which closely follows the degree of disordering of the xanthan molecules. Similarly, for a fixed T p, increasing the ionic strength stabilises the ordered xanthan conformation and is found to reduce the measured storage modulus ( G′). These results are discussed in the light of the current models for mixed-biopolymer gelation.