Starch polysaccharide hydrocolloid gels

Abstract

Studies on the formation of gels from 5 % w/w suspensions of potato, cassava, corn, and oat starches in 0.05 or 0.2 % w/w aqueous solutions of one of Arabic, carob, guar, karaya, or xanthan gum, and κ-carrageen shed light on the rules governing rheological properties of resulting gels. Avoiding phase separation in a plant gum - starch solution is crucial for a high viscosity of gels formed. Partner of anionic starch in the gel should be nonionic unless the partnering plant gum has low Mw and/or high polydispersity (e.g. karaya gum). Nonionic starches combine with gums regardless they are anionic or neutral. Usually, Arabic and xanthan gums and κ-carrageen provided less viscous mixed gels with starches. Amylose and exceptionally high lipid contents in starches could also be essential factors influencing gelation. Admixture of plant gums into starch gels reduced elasticity of the mixed gels.