Food gels: Gelling process and new applications

Food gels are viscoelastic substances and several gelled products are manufactured throughout the world. The gelling agents in foods are usually polysaccharides and proteins. In food gels, the polymer molecules are not cross-linked by covalent bonds with the exception of disulphide bonds in some protein gels. Instead, the molecules are held together by a combination of weak inter-molecular forces like hydrogen bonds, electrostatic forces, Van der Waals forces, and hydrophobic interactions. Polysaccharides including hydrocolloids are strongly hydrated in aqueous medium but they tend to have less ordered structures. Mechanism of gelation depends on the nature of gelling agent(s) and on the conditions of gel formation like temperature, presence of ions, pH, concentration of gelling agents, etc. Characterisation of gels can be performed by several ways of which rheological measurements are frequently practised. Multi-component or mixed gel system is an important area of interest in which two or more gelling c...