Guide to Beverage Thickeners: Types and Uses

Thickeners, a common class of food additives, play a vital role in improving the consistency, suspension stability, and overall texture of beverages. This article explores the characteristics and applications of popular thickeners in beverages, helping manufacturers choose the right ones for their product formulations.

Agar Agar in Beverages

• Thickening and Stabilizing Properties

Compared to other thickening agents, Agar Agar provides a full-bodied yet refreshing texture with only a small amount of addition, and it does not leave a sticky aftertaste.

• Superior Flavor Release

Agar does not mask the natural flavors of the food, allowing the drink's original taste to shine.

• Thixotropic Viscosity

It gives beverages a thick texture but with minimal aftertaste. The drink goes down smoothly, offering a very pleasant mouthfeel.

• Gelling Properties

At low concentrations, agar can form a three-dimensional network in the solution, providing excellent suspension properties for insoluble components like proteins, fibers, and powders. It also improves the shelf stability of beverages by preventing water separation or layering.

Xanthan Gum in Beverages

• Highly Efficient Thickening

Xanthan gum can significantly increase beverage viscosity at low concentrations (less than 0.5%), making it a cost-effective choice. It is commonly used in drinks like almond milk, where it helps prevent sedimentation and layering during storage.

• Shear-Thinning Properties

Xanthan gum exhibits pseudoplastic behavior, meaning the viscosity decreases under shear (during drinking), providing a smoother mouthfeel, and returns to its original viscosity afterward.

• Compatibility with Other Additives

Xanthan gum works well with other thickeners and emulsifiers, providing stability in beverages, even during pasteurization.

• Applications

Xanthan gum is widely used in almond milk to prevent sedimentation and layering during production and storage. Its meltability and low usage levels contribute to a superior mouthfeel and more effective flavor release than other gums. It's also used in powdered drinks, with a standard usage rate of 1%. In carbonated drinks, xanthan gum helps stabilize the gas.

Carrageenan in Beverages

Carrageenan is a white or pale yellow powder, tasteless and odorless, and dissolves completely in hot water above 60°C. It is insoluble in organic solvents. Carrageenan is most stable at a pH of 9, but it can withstand high temperatures in solutions with a pH above 6. However, when the pH is below 3.5, heating may cause acid hydrolysis. In the presence of potassium or calcium ions, carrageenan forms a reversible gel.

Carrageenan acts as a thickener, suspending agent, gelling agent, emulsifier, and stabilizer, with typical usage rates ranging from 0.03% to 0.5%. For example, in cocoa milk, the usage rate is 0.025% to 0.035%, in milk gel, it's 0.2% to 0.3%, and in yogurt, it's 0.02% to 0.03%. In heated, sterilized beverages and milk gels, K-type carrageenan is recommended. When combined with locust bean gum, carrageenan can enhance gel strength and viscosity.

Pectin in Beverages

Pectin is a brown or grayish-white powder that forms a viscous, creamy solution when dissolved in water. It has good heat resistance and is insoluble in organic solvents.

Pectin is highly stable in acidic environments, making it an excellent thickener in various acidic food products. Pectin with a methoxyl content higher than 7% is classified as high methoxyl pectin, while pectin with less than 7% methoxyl content is classified as low methoxyl pectin. The methoxyl content affects the gelling properties of pectin.

In juice drinks or powdered beverages, pectin increases viscosity and stabilizes suspensions of essential oils and fruit particles. The usage rate is 0.05% to 0.1% in juice drinks and 0.1% to 0.2% in concentrated juices. Pectin is more soluble when mixed with syrup or sugar before dissolving in water.

In dairy beverage production, high methoxyl pectin improves flavor and texture. It prevents layering, especially in sterilized milk products where sedimentation is common. Pectin helps inhibit this separation.

Gelatin in Beverages

Gelatin is a colorless or pale yellow, translucent, brittle powder or thin sheets with almost no taste or odor. It swells 5 to 10 times its weight in cold water and dissolves in hot water, glycerin, or acetic acid. It does not dissolve in ether or ethanol. When dissolved in hot water, it forms a viscous solution. A solution of 10% to 15% can form a gel, while concentrations below 5% do not gel.

The gelling temperature of gelatin depends on its concentration, the type and concentration of salts, and the pH of the solution. It liquefies at about 30°C and gels between 20°C and 25°C. Gelatin solutions can be boiled for extended periods without losing their gelling ability, though they may degrade into peptones when reheated.

Gelatin is primarily composed of over 83% protein, with less than 15% water and less than 2% ash. It acts as a thickener and stabilizer in beverages and is also used as a clarifying agent for fruit juices and wines.

Sodium Carboxymethyl Cellulose (CMC) in Beverages

CMC is a cellulose derivative with a polymerization degree of 200–500 and a substitution degree (DS) of 0.6–0.7. It is a white or off-white, odorless powder or fibrous material with hygroscopic properties. Its DS determines its solubility properties.

When the DS is above 0.3, CMC is soluble in alkaline solutions. The viscosity of CMC solutions depends on the pH and degree of polymerization. When the DS is between 0.5 and 0.8, CMC remains stable in acidic conditions. CMC dissolves easily in water to form a transparent, viscous solution, and its viscosity varies with concentration and temperature. It remains stable below 60°C, but its viscosity decreases with prolonged heating above 80°C.

Sodium Carboxymethyl Cellulose (CMC) is widely used in the soft drink industry for its ability to form high-viscosity solutions in water. However, it is not inherently stable in acidic conditions, so acid-resistant CMC-Na must be used in acidic beverages.

In dairy beverages, CMC-Na is added before acidification to prevent casein precipitation, which extends the product's shelf life. In juice drinks, particularly those with pulp, CMC-Na prevents sedimentation.

In Conclusion

Thickeners play an important role in beverages. By reasonably choosing and using thickeners, the taste, stability, and appearance of beverages can be improved to meet consumer needs. At the same time, when using thickeners, attention should be paid to choosing the right thickener, controlling the usage amount, paying attention to compatibility with other ingredients, and complying with regulatory standards to ensure product safety and quality.