Definition and functional properties of food glue

Definition of food glue
It usually refers to a macromolecular substance that dissolves in water and can be fully hydrated under certain conditions to form a viscous, slippery or jelly liquid. It can provide thickening, viscosifying, adhesion, and gel-forming capabilities in processed foods. , hardness, brittleness, compactness, stable emulsification, suspension, etc., so that food can obtain various shapes and tastes such as hard, soft, brittle, sticky, thick, etc., so it is often called food thickener , viscosifier, gelling agent, stabilizer, suspending agent, edible gum, colloid, etc.

Classification of food glue:
1. Natural
Plant polysaccharides: pectin, gum arabic, guar gum, locust bean gum, etc.;
Seaweed polysaccharides: agar, alginic acid, carrageenan, etc.;
Microbial polysaccharides: xanthan gum, pullulan;
animal:
Polysaccharide: carapace; protein: gelatin.

2. Synthesis
Sodium carboxymethylcellulose, propylene glycol, modified starch, etc.

Functional properties of food glue

Thickening; gelling; dietary fiber function; emulsification, stability, as a coating agent and capsule; suspension dispersibility; water retention; crystallization control.

1. Nature

(1) Gel
When a thickener with a specific molecular structure is dissolved in the system, the concentration reaches a certain value, and the system meets certain requirements, the system forms a three-dimensional network structure through the following functions:
Mutual cross-linking and chelation between macromolecular chains of thickener
Strong affinity between thickener macromolecules and solvent molecules (water)

Agar: 1% concentration can form a gel
Alginate: thermally irreversible gel (does not dilute when heated) – raw material for artificial jelly

(2) Interaction
Negative effect: Gum acacia reduces the viscosity of tragacanth gum
Synergy: After a certain period of time, the viscosity of the mixed liquid is greater than the sum of the viscosities of the respective thickeners alone

In the practical application of thickeners, it is often not possible to obtain the desired effect by using one thickener alone, and it often needs to be used in combination to exert a synergistic effect.
Such as: CMC and gelatin, carrageenan, guar gum and CMC, agar and locust bean gum, xanthan gum and locust bean gum, etc.