Applications of thickeners in food

Application in the production of jelly

Food thickeners are often used in the production and processing of jelly with two or more synergistic effects, so as to achieve the best results needed for jelly. Gellan gum is an extracellular linear polysaccharide synthesised and secreted by Pseudomonas aeruginosa during the fermentation of pure species of carbohydrates. Due to its good clarity and sufficient thermal stability, gellan gum is used in combination with xanthan gum to produce ready-to-eat dessert gels. Deacylated gellan gum is used to improve the moisture retention, flavour release and storage stability of puddings and to reduce dehydration shrinkage.

Metal cations play a key role in the formation of gellan gum gels. The formation of the "linkage zone" is facilitated by the direct attachment of the cation to the carboxyl group of the polysaccharide molecule by means of spot binding, which weakens the electrostatic repulsion between the double helix chains.

Carrageenan is a natural algal polysaccharide, a hydrophilic linear non-homogeneous polysaccharide containing sulphate groups, consisting of 1,4-beta-D-galactopyranose and 1,3-alpha-D-galactopyranose as the basic backbone, which can be extracted from the cell walls of red algae. When carrageenan is heated and then slowly cooled, the shape of the molecules gradually changes from initially curly to spiral and eventually from single to double helix, at which point a three-dimensional mesh structure is formed.

At lower concentrations carrageenan can form a thermally reversible gel, which at this moment has a good transparency and improves the appearance of the jelly. Carrageenan is the most common thickener used in jelly production and has been used in food formulations in synergy with other thickeners. When carrageenan is combined with acacia bean gum, gelatin, xanthan gum and gum arabic, the gel strength and elasticity can be significantly improved.

Application in yoghurt

Thickening agents can improve the viscosity of yoghurt, stabilise its properties, prevent whey precipitation and effectively improve the texture and taste of yoghurt products. Propylene glycol alginate and modified starch can play a synergistic role when used as thickeners at the same time. The optimum amount of both thickeners is 0.15% (W/W) for propylene glycol alginate and 1.20% for modified starch.

The addition of 0.2% propylene glycol alginate to the yoghurt production process increases the overall water retention capacity of the product by 10.9% and effectively prevents whey precipitation. When 0.2% propylene glycol alginate (W/W), 0.3% sodium carboxymethyl cellulose, 0.1% high ester pectin and 0.015% (W/W) sucrose esters are added in combination, the stability and taste of the product is optimal.