4 Tips on How to Select the Best Food Hydrocolloids

When you are selecting the best food hydrocolloids, there are two criteria that you must get right.

The first question to consider is what textural properties you are looking for in the final product and what you want the food hydrocolloids to achieve.

Are you looking for sensory properties and textural properties?

Do you need a thickening or a more gelled structure?

If the end product is a multi-phase system (foam, suspension, emulsion), then the hydrocolloid should also provide some stabilization properties.

1. Functionality of Food Hydrocolloids in the Final Food Products

Hydrocolloid	T = Thickening G = Gelling S = Stabilisation Description of Texture	Description of Texture
Alginates	T, G	Alginates or more specifically sodium alginates can be used as a thickening agent (different grades offer a range of viscosities). Alginates can form strong, cohesive, thermo-resistant gels in the presence of calcium ions.
Carrageenan, Iota	T, G	Iota carrageenan forms elastic gels and thixotropic fluids.
Carrageenan, Kappa	G, S	Kappa carrageenan forms firm gels. Very low dosages of kappa-carrageenan in milk show positive interaction with milk proteins, resulting in the suspension of cocoa particles.
Carrageenan, Lambda	T	Lambda carrageenan forms viscous, non-gelling solutions.
Cellulosics, CMC	T, S	CMC forms clear, viscous solutions (a range of viscosities are available). CMC shows protective colloid properties in acidified milk drinks.
Cellulosics, MC, and HPMC	T, G	HPMC and MC, which are dissolved in cold water, will gel upon heating (thermo-gelling). Different grades with different viscosities / different gelation temperatures are available. The gel is thermo-reversible since the system will return to a viscous liquid phase upon cooling.
Gellan gum	G, S	Gellan gum is available in two forms, high and low acyl content. Low acyl gellan gum forms firm, non-elastic, brittle gels. High acyl gellan gum forms soft, very elastic gels. By varying the ratios of the two forms, gellan can produce a wide variety of textures. Gellan gum can be used to stabilize suspensions by forming a solution with a weak gel structure, known as a fluid gel.
Guar gum	T	Guar gum forms viscous solutions with a long texture.
Gum arabic	T, G	Gum arabic is used in confectionery for its gelling properties. Gum arabic is used in flavor and color emulsions as an emulsifying agent.
Locust Bean Gum (LBG)	T, (G)	LBG forms viscous, shear-thinning solutions. LBG can form gels in combination with other hydrocolloids. LBG is excellent in syneresis control.
Pectin, HM	G, S	High methoxyl pectins form gels at low pH and in the presence of sugar. HM pectins are classified as rapid set, medium set, or slow set. HM pectins are also used in acidified milk drinks (pH < 4,6) to stabilize the proteins.
Pectin, LM	G	(Amidated) low methoxyl pectins also form gels – partly shear reversible.
Xanthan gum	T, S	Xanthan gum forms pseudo-plastic viscous solutions, which are pH and temperature stable compared to other thickeners. The pseudo-plasticity makes xanthan gum also suitable as a stabilizer of suspensions, emulsions, and foams.

2. Formulating with Food Hydrocolloids; Solubility, Compatibility and Thickening or Gelling Mechanism

2.1 Solubility, Compatibility

Most food hydrocolloids on the market are supplied in powder form.

To fully utilize their function (to produce viscosity or gel), hydrocolloid solutions must be prepared.

When dissolving hydrocolloids, the applied temperature along with the presence of other ingredients can have an effect ( which may be both positive and negative).

Hydrocolloid	Solubility	Solution Clarity	pH Range in Application	Acid Stability
Alginates	Cold or hot soluble in a calcium-free medium. In a high calcium environment, sequestrants are needed to dissolve the alginate.	Good	4.5 - 7	Fair (will form alginic acid at low pH)
Carrageenans	Iota and Kappa: hot soluble, above 60 °C. Lambda is also cold soluble	Good	4.5 - 7	Poor
Cellulosics, CMC	Cold or hot soluble	Excellent	3.5 - 7	Good
Cellulosics, MC and HPMC	Cold soluble	Excellent	4 - 7	Good
Gellan gum	Hot soluble in an ion-free medium. In a high ion environment, sequestrants are needed to dissolve gellan.	HA - Good LA - Poor	3 - 7	Good
Guar gum	Cold or hot soluble	Fair	4 - 7	Fair
Gum Arabic	Cold or hot soluble	Excellent	2 - 7	Good
Locust bean gum	Hot soluble, above 80 °C	Fair	4 - 7	Good
Pectin	Hot soluble, above 60 °C	Excellent	2 - 7	Very Good
Xanthan gum	Cold or hot soluble	Fair	2 - 7	Very Good

2.2 Thickening or Gelling Mechanism

When food hydrocolloids are dissolved, they either work alone or require other substances, such as ions, to produce viscous or gel properties.

Hydrocolloid	Act Alone or Act With	Description of Thickening or Gelling Mechanism
Alginates	With calcium ions	Sodium alginates are composed of two building blocks: mannuronic acid (M) and guluronic acid (G). In the presence of calcium ions, the G-blocks in the alginate chain will join together and form a gel structure. Alginates with a high content of G-blocks, form stronger gels than alginates with high M-blocks content. When there is enough free calcium available, the alginate gel will become thermo-irreversible. Please note alginate gel forms in cold conditions.
Carrageenan, Iota	With calcium ions	After being heat-treated to dissolve the carrageenan, the molecules will join together during cooling, thereby forming a gel structure. The iota carrageenan network forms a transparent, elastic gel. When stirring this network can easily be destroyed, but the gel is rebuilt quickly as soon as the mechanical action stops. The gels of iota carrageenan are thermo-reversible.
Carrageenan, Kappa	With potassium ions	After being heat-treated to dissolve the carrageenan, the molecules will join together during cooling, thereby forming a gel structure. Kappa carrageenan needs the presence of potassium ions to form a firm, brittle gel. The gels of kappa-carrageenan are thermo-reversible. Kappa carrageenan shows synergistic gel strength when combined with locust bean gum.
Carrageenan, Lambda	Alone	The molecules of lambda carrageenan do not strongly join together and therefore do not form gels. Lambda carrageenan functions as a thickener.
Cellulosics, CMC	Alone	CMC acts alone to form viscous solutions. The wide variety of viscosity ranges available, make it a versatile hydrocolloid for many applications.
Cellulosics, MC, and HPMC	Alone	When the temperature of an MC/HPMC solution is increased, the polymers lose their water of hydration, and the viscosity decreases. When the gel point is reached, the dehydration of the polymers causes polymer-to-polymer interaction and the solution begins to gel. Gel strength builds as the temperature is held above the gel point. When the system is cooled, the gel begins to reverse, and the system becomes a liquid viscous system again. Depending on the type of MC or HPMC the gel point can vary from 50 °C to 90 °C.
Gellan gum	With potassium, sodium, and calcium ions	Gellan gum forms gels with divalent as well as monovalent ions. Calcium ions are more effective in making gels than sodium and potassium ions. The concentration of ions also influences the gelling and melting temperature of the gel which is formed. Low acyl gellan gum tends to form thermo-stable gels, whereas high acyl gellan gum tends to form thermoreversible gels.
Guar gum	Alone or with xanthan gum	Guar gum acts alone to form viscous solutions. In combination with xanthan gum, a synergistic viscosity development can be noticed.
Gum arabic	Alone	Gum arabic is a unique molecule and contains 2 to 3% peptides as an integral part of the structure. It is believed that these peptide fractions are responsible for the emulsifying capacity. Gum arabic forms very low viscous solutions, concentrations up to 50% can be achieved.
Locust bean gum (LBG)	Alone or with xanthan gum or carrageenan	LBG forms viscous, shear-thinning solutions. In combination with xanthan gum and/or kappa carrageenan, LBG forms mixed gels with an elastic texture, which shows no syneresis.
Pectin, HM	With sugar and low pH	HM (high methoxy) pectins form thermo- irreversible gels when the pH is low (< pH 3.5) and the sugar concentration is high (dry matter content > 55 %).
Pectin, HM	With protein	HM pectins are excellent stabilizers of acid milk drinks. They act as a protective colloid, preventing the casein particles from coagulating and sedimenting when added before acidification.
Pectin, LM	With calcium ions	LM (amidated) low methoxy pectins can form thermo-reversible as well as thermo-stable gels. Depending on the calcium concentration and the calcium reactivity of the specific grade, a range of textures can be achieved.
Xanthan gum	Alone or with guar gum	Xanthan gum acts alone to form viscous, pseudo-plastic solutions. In combination with guar gum, a synergistic viscosity development can be noticed.

3. Food Hydrocolloid Applications

There are numerous areas of application for food hydrocolloids and there are many wonderful combinations of food hydrocolloids that have direct synergistic effects.

Therefore, the application grid provided below and the other information provided earlier should be used only as a guideline to provide a starting point for development work.

	ALGINATES	CARRAGEENAN	CELLULOSICS, CMC	CELLULOSICS, MC + HPMC	GELLAN GUM	GUAR GUM	GUM ARABIC	LOCUST BEAN GUM	PECTIN	XANTHAN GUM
Bakery products (incl. bakery fillings)	■■		■■	■	■	■■		■	■■	■■
Beverages		■	■■		■	■	■		■■	■
Confectionery					■		■■		■■
Convenience: sauces, dressings, soups, marinades		■	■	■		■■		■		■■
Dairy, acidified/fermented drinks, desserts			■■						■■
Dairy, sweet drinks, desserts	■	■■	■		■	■		■
Flavor emulsions			■	■			■■		■
Fruit preparations, jams, marmalades	■■	■	■	■	■	■		■	■■	■
Ice-cream	■	■	■■			■		■■	■	■
Meat and poultry processing	■■	■■	■	■■		■				■
Vegetable, and potato preparations	■		■	■■						■

4. Hydrocolloid Sources

Please find below information on the source of the different food hydrocolloids, plus abbreviations and synonyms which are used in the industry.

Hydrocolloid	Abbreviations Synonyms	E Number	Raw Material
Alginates	Sodium alginates	E 401	Extracted from brown seaweed
Carrageenan	Iota, Kappa, Lambda Carrageenan	E 407	Extracted from red seaweed
Cellulosics, CMC	Carboxymethylcellulose Cellulose gum	E 466	Manufactured using cellulose (from wood pulp or cotton linters) as base material
Cellulosics, MC and HPMC	Methylcellulose Hydroxypropylmethylcellulose	E 461 E 464	Manufactured using cellulose (from wood pulp or cotton linters) as base material
Gellan gum		E 418	Produced by the fermentation process
Guar gum *		E 412	Obtained from the endosperm of the guar seed
Gum arabic	Acacia gum	E 414	Exudate from the acacia tree
Locust bean gum (LBG) *	Carob (bean) gum	E 410	Obtained from the endosperm of the seeds of the carob tree.
Pectin		E 440	Extracted from apple pomace and/or citrus peel
Xanthan gum		E 415	Produced by the fermentation process

* Galactomannans is a group name, locust bean gum, and guar gum are both galactomannans

Hydrocolloids Related Regulation

Thickening and gelling agents are food additives and their use is subject to several laws and regulations. For the member states of the European Union, their use is inter alia subject to Regulation (EC) No 1333/2008 on food additives published in December 2008.

Annex I of this Regulation describes the functional classes of food additives:

‘gelling agents’ are substances that give a foodstuff texture through the formation of a gel.

‘stabilizers’ are substances that make it possible to maintain the Physico-chemical state of a foodstuff; stabilizers include substances that enable the maintenance of a homogenous dispersion of two or more immiscible substances in a foodstuff, substances which stabilize, retain or intensify an existing color of a foodstuff and substances which increase the binding capacity of the food, including the formation of crosslinks between proteins enabling the binding of food pieces into re-constituted food;

‘thickeners’ are substances that increase the viscosity of a foodstuff;

Annex II provides the community list of food additives approved for use in foods

The list is published in November 2011, in Commission Regulation (EU) No 1129/2011 amending Annex II to Regulation (EC) No 1333/2008.

The list includes:

■ The name of the food additives and the E numbers (part B)

■ Definitions of groups of additives (part C)

■ The foods to which the food additives may be added, food categories (part D)

■ The conditions under which the food additives may be used (part E)

Specifications of Food Additives

Commission Regulation (EU) No 231/2012 published in March 2012, provides the specifications, such as purity criteria, origin, and other necessary information, for food additives.

For a complete overview of approved food hydrocolloids and the exact approved applications, dosage, and conditions of use in the European Union, the most current regulations and directives as well as any other applicable national laws and regulations must be checked. The complete texts, as well as consolidated versions of the European Regulations and directives with the last updates, can be viewed and downloaded from the following website: http://eur-lex.europa.eu/en/index.htm

For any use outside the European Union, please check carefully the laws and regulations applicable to you. Please keep in mind that you are responsible for compliance with any applicable legal and regulatory requirements.