Stabilizers, thickeners, and gelling agents are compounds that improve stability, texture, viscosity and firmness in foods. They include polysaccharides like alginates, carrageenans, and gums as well as proteins. Polysaccharides can be non-ionic, anionic, or cationic. Anionic polysaccharides interact with positive charges on foods like milk to stabilize them. Cationic compounds like chitosan are used for their emulsifying properties. Protein stabilizers such as soy prevent disintegration during cooking of foods like burgers. These additives play an important role in processing and structure of foods that naturally lack stabilizing components.

1. Stabilisers, thickeners and
gelling agents

2. Definition
stabilisers, thickeners and gelling agents are a
group of compounds which play a very
important role in the food industry to improve
stability, texture, viscosity and make food
products firmer (Feddersen and Thorp 1993)

3. The molecules used as stabilisers, thickeners or gelling
agents are macromolecules which, when dissolved or
dispersed in aqueous media, are capable of causing an
increase in the viscosity or gel formation
Most of these compounds are natural from either plant
or animal origin (G´omez-D´ıaz and Navaza 2004).

4. • Among the most widely used stabilisers in the
food industry are alginates, carrageenans,
agar, guar gum, arabic gum, methylcellulose
and carboxymethylcellulose.
• The same molecules are also used in the food
industry to perform a variety of roles, for
example as emulsifiers or preservatives.

5. Function
• Stabilisers in foodstuffs prevent food
components from separating
• they also give food a consistent texture.
• Gelling agents are useful when the
consistency of a particular food has to be
altered/modified to meet consumer demand.

6. Classification

7. Classification
Stabilisers and thickeners may be
divided into two main classes:
• polysaccharides
• proteins

8. Polysaccharides comprise three main subclasses:
• non-ionic (neutral), for example hydroxyethylcellulose
and dextran;
• anionic, for example xanthan, carrageenan, guar gum,
alginate and carboxymethylcellulose (Cao et al. 1990;
Dickinson and Galazka 1991; Samant et al. 1993; Ward-
Smith et al. 1994; Dickinson 1996); and
• cationic such as arginine hydrochloride and chitosan (a
linear copolymer of D-glucosamine and N-acetyl-D-
glucosamine units connected through -(1–4) linkages).

9. Non-ionic (neutral) polysaccharide stabilisers
• Non-ionic (neutral) polysaccharides such
hydroxyethyl cellulose and hydroxypropyl
cellulose are widely used as food stabilisers
• Their mechanism of adsorption involves the
formation of steric barriers which are produced
when the adsorbed polymer extends its chain to
the water phase (Ain-Ai and Gupta 2008).
• hydroxypropyl cellulose contains both
hydrophobicity and hydrophilicity characters

10. Non-ionic (neutral) polysaccharide stabilisers

11. Non-ionic (neutral) polysaccharide stabilisers
(b) hydroxyethyl cellulose polymers and (c) hydroxypropyl cellulose polymer
(Hansen 1993; Ain-Ai and Gupta 2008)

12. Anionic polysaccharides stabilisers
• Anionic polysaccharides (e.g. carboxymethyl
cellulose, pectin, alginates, carrageenans, guar
gums and gelatins) are employed as stabilisers
in dairy products in particular (Marshall 1995).
• Their mechanism involves interaction with the
positive charges on the surface of foodstuffs
such as milk (casein micelles) to stabilise the
casein network.

13. Anionic polysaccharides stabilisers

14. Anionic polysaccharides stabilisers

15. Anionic polysaccharides stabilisers

16. Anionic polysaccharides stabilisers

17. Anionic polysaccharides stabilisers

18. Anionic polysaccharides stabilisers

19. Anionic polysaccharides stabilisers

20. Cationic polysaccharide food stabilisers
• Chitosan is a linear copolymer composed of D-
glucosamine and N-acetyl-D-glucosamine units
linked by -(1–4) linkages.
• It is attractive for use as a food additive
(stabiliser) due to its abundance and chemical
properties including its hypocholesterolaemic and
hypolipidaemic characteristics (Nauss et al. 1983;
Winterowd and Sandford 1995; Muzzarelli 1996,
1997).

21. Cationic polysaccharide food stabilisers
• Chitosan is also known for its good co-
adsorption properties on lipid droplets
covered with anionic lipid emulsifiers (Alamelu
and Panduranga Rao 1990; Magdassi et al.
1997) as well as its emulsifying properties
(Schulz et al. 1998; Del Blanco et al. 1999).
• Arginine hydrochloride is another example of
a cationic polysaccharide.

22. PROTEIN-BASED FOOD STABILISERS
• Protein-based stabilisers such as soya proteins are
normally used in foods such as burgers or sausages for
vegetarians.
• Soya proteins in these vegetarian food preparations
prevent the food from disintegration during cooking
• Gelatin is one of protein based stabiliser. It is a product
of the structural and chemical degradation of collagen
derived from animal skin and bones

24. Analysis Methode
• electrophoresis or immunoassays (e.g.
enzyme linked immunoassay or ELISA)
• Polarimetry and refractometry
• Fluorophore-assisted carbohydrate
electrophoresis (FACE)

25. Further Thinking
Stabilisers, thickeners, gums and gelling agents all
play an important role in the processing of fruits
such as strawberry and other industrially processed
foods, especially the types of foods which do not
contain gelatinous compounds or any other
stabilising ingredients (e.g. pectin).
These have to be added to maintain their structure
as well as their physical properties during the
processing period.