What Are Hydrocolloids in Food?
Hydrocolloids are functional carbohydrates used in many foods to enhance their shelf-life and quality. These additives are used to modify the viscosity and texture of food products like ice cream, salad dressings, gravies, processed meats, and beverages. They are chiefly used to modify the rheology of the food system, specifically viscosity and texture. Some are used alone while others are used in synergistic combinations.
Hydrocolloids are used as thickening agents, however, some of these additives can be used in the formation of gels. Much of this is related to the way each ingredient reacts to water, including its solubility and how it performs when exposed to varying temperatures. As water is immobilized, the gel can take on unique characteristics depending on the type of hydrocolloid used.
What Do Hydrocolloids Do in Food?
Rheology of food deals with the flow properties of the individual components within a food system and its impact on the physical structural properties of the product. Certain ingredients can influence food rheology passively or actively, changing the way the food is processed and impacting its final form. Hydrocolloids are ingredients that are added to food systems to purposely alter their rheology in regards to thickness and stability or to act as films, casings, or fat replacements. Many hydrocolloids are used in a range of foods and beverages and are often combined to yield the most advantageous results.
As many health-conscious consumers seek out foods that align with their dietary needs, companies continue to look for ways to modify their foods to meet these needs. Hydrocolloids can be used as fat replacements in some foods. These additives can partially replace fat by using starches dissolved in water that create stable gels that also enhance viscosity. Guar and xanthan gum are two common hydrocolloids that are used as fat replacers.
TYPES OF HYDROCOLLOIDS
There are two main categories of hydrocolloids — those used as thickeners and those used as gelling agents.
Some foods require edible skins, like coatings, films, or casings. Hydrocolloids can be used to create these thin, edible layers that allow moisture, gas, lipids, and aromas of the food to migrate. They can also be used in a gelatinous form to prevent oxidation and moisture loss. Forms of these hydrophilic hydrocolloids include cellulose, alginate, and carrageenan.
One of the primary uses for hydrocolloids in food is to act as a thickening agent. Depending on the type and concentration of hydrocolloid used, the thickening effect will be determined by the pH and temperature of the food system. For instance, gum Arabic is a low viscosity gum that is used in beverages while guar gum is highly viscous and is ideal for substances like ice cream and cake batter.
Hydrocolloids are also used as stabilizers in various foods. These include xanthan gum, sodium alginate, carrageenan, carboxymethyl cellulose, and guar gum. One excellent example of a hydrocolloid used as a stabilizer can be found in the creation of ice cream. Low-temperature storage would cause ice crystals to form on ice cream, however, these stabilizers prevent the substance from icing. It also promotes flavor release and maintains the ice cream's texture without becoming too frozen, soft or gummy.
- Xanthan gum is a hydrocolloid commonly used as a binding and thickening agent in a variety of foods. Its unusual properties have made it a popular additive in baked goods, dairy products, canned meats, and condiments. Some applications for xanthan gum include a substitute for gluten in dough, a binding agent that prevents oils and acids in salad dressings from separating, and as a sweetener for beverages.
- Carboxymethyl cellulose, referred to as cellulose gum or simply CMC, is a water-soluble compound that is used to create a clear solution. The varying viscosity of these solutions gives it utility in creating both smooth flowing and thixotropic substances — a smooth CMC solution is used for syrups and frostings while a thicker thixotropic CMC solution is used for purees and sauces.
- Methyl cellulose is a binding agent used in prepackaged meals, baked goods, veggie patties, and other foods. Although it can also be used as a gelling agent, it has been used as a thickener in foods like pie and pastry fillings, batters, bakery products, and extruded foods.
- Gum Arabic, also known as acacia, is used commonly as a thickening agent, emulsifier, and stabilizer in both food and beverages. It has a low viscosity and can be used to impact the body and textures of food.
- Carrageenan has its most useful applications in dairy-based substances. These foods include puddings, milkshakes, and ice cream. Carrageenan is the best hydrocolloid used as a gelling agent in milk but can also find significant use in other applications. This hydrocolloid can also be found in tofu, meats, and jellies.
- Galactomannans are water soluble hydrocolloids that have applications throughout a variety of industries. Within the food industry, they can be used to form stable aqueous solutions with a high viscosity. These additives are extracted from seeds using either ethanol or water as a solvent. Because low concentrations can form highly viscous solutions, galactomannans are used to create edible films and coatings for foods like fruits and cheeses. Galactomannans also work to decrease production and transfer of natural gases to enhance the quality and stability of food products.
- Konjac Mannan, also known as Konjac glucomannan or KGM, is a water-binding solution that is used for replacing fats in food systems. It is a temperature sensitive gel formed when heated. KGM is composed of glucose and when included in foods can help promote weight loss, reduce cholesterol, and aid in relieving constipation.
- Gum tragacanth absorbs water well and maintains a high viscosity after cooking. It is used as an emulsifier for condiments like salad dressings and sauces.
- Guar gum is a non-gelling agent and commonly used galactomannan for thickening and binding in the food industry. It is soluble in both hot and cold water and actually changes the behavior of the water present in food. This enables it to produce high viscosity in items like ketchup. It's also used to improve the shelf life of beverages, stabilize frozen dairy products, salad dressings, and sauces and acts as a binding agent in processed meat products.
- Agar is a gelling agent sourced from red algae or seaweed. It's commonly used in traditional Japanese foods like desserts, meats and fish, dairy products, and beverages. Agar has a high melting point which can be increased when salt is added to the food system, making it a stronger alternative to gelatin and carrageenan.
- Gellan gum features properties that make it a unique and useful hydrocolloid in food applications. Among its many uses, it can act as a starch replacement to promote flavor release, improve moisture retention, and increase storage stability. Gellan gum is frequently found in baked goods, juices, and other beverages.
- Alginate can be used throughout different food systems ranging from sauces and dressings to dairy products, meats, and vegetables. Alginates are unique because they can be used to form thermoreversible gelling agents, act as emulsifiers and thicken or coat food systems. For instance, propylene glycol alginate has the properties of an emulsifier and hydrocolloid which can form stable foams for beer and other beverages.
- Modified starches and natural starches are the most common hydrocolloids used as thickening agents. One benefit to using starch is that it doesn't impact the flavor of the food when used in limited concentrations. Modified starches are combined with other hydrocolloids like xanthan gum to increase the thickness of sauces and soups.
- Low methoxyl pectin and high methoxyl pectin are additives commonly used to give texture to jams and jellies. Their degree of esterification influences their ability to form a gel. High methoxyl pectin requires higher amounts of sugar to gel while low methoxyl pectin needs calcium to gel. Low methoxyl pectin is used to create sugar-free and low-sugar jellies while high methoxyl pectin is used to create chunky and clear jellies.
- Methyl cellulose and hydroxypropylmethyl cellulose can also be used as gelling agents in food. When dissolved in cold water, methyl cellulose can form a gel when heated. It's believed that this gel stays in the stomach for a longer period of time and can make an individual feel fuller. Hydroxypropylmethyl cellulose is a viscous dietary fiber that can improve glucose control and decrease diabetic wasting.
How Hydrocolloids Are Used in Food Industry Applications
Many different types of hydrocolloids can be found in a variety of foods — some are even formulated specifically for particular food groups or categories. As previously mentioned, they make great thickening agents for dairy products, especially ice cream. Combinations of colloidal stabilizers, like alginate and carrageenan, achieve a higher effectiveness than a single hydrocolloid used along. One stabilizing gum, for instance, that may be incompatible with milk proteins can be integrated with another hydrocolloid like carrageenan to increase substance thickening while inhibiting phase separation.
Hydrocolloid additives are commonly used in the baking industry, particularly as emulsifiers. These ingredients can improve the shelf-life of the product, bind the dough to make it stronger, help the product retain water during the resting time, and improve the texture of bread. Alginates, for instance, are used to stabilize icings and toppings on baked goods. Carboxymethyl cellulose can improve the mouth-feel of the product, xanthan gum improves the stability of frozen baked goods, and guar gum can increase their shelf-life through moisture retention.
Salad dressings, sauces, and gravies use hydrocolloids like gum tragacanth, locust bean, and gum guar. Some condiments, like mayonnaise, do not use hydrocolloid stabilizers while others like ketchup do. Salad dressings often use xanthan gum and gum tragacanth for viscosity, modified starches for stability during processing and storage, microcrystalline cellulose as a suspension agent, and propylene glycol alginate as an emulsifying agent.
However, sauces already containing a natural emulsifier or stabilizer will not benefit from an additive. One example is Hollandaise sauce, which already contains an emulsifying agent. When xanthan gum and carrageenan were added to the sauce, it negatively impacted color, viscosity, and palatability.
Beverages like beer and juices will use hydrocolloids as an emulsifier and stabilizer. Juices may use CMC and xanthan gum to increase viscosity without impacting color, taste, texture, or other desired characteristics. Gellan gum forms a transparent fluid-gel that is useful in beverage dispersions while the low viscosity of gum Arabic makes it ideal for fruit juices, soft drinks, and other beverages.
Hydrocolloids like carrageenans are used in meat, poultry, and seafood products for a variety of reasons, particularly in reducing fat content. However, fat naturally impacts the taste and texture of the meat. Instead of removing the fat and losing these desirable characteristics, hydrocolloids are used as substitutes to retain those benefits.
Galactomannans are used as ingredients in fruit preparation. The temperature of the filling directly effects how strong of a gel these types of hydrocolloids can create. For instance, if the filling temperature exceeds the setting temperature, the gel will remain strong. If not, it will be weaker yet enhance the viscosity of the fruit preparation. To achieve both benefits, a gelling hydrocolloid and a thickening hydrocolloid, like a locust bean gum and a carrageenan, are used simultaneously without damaging the recipe.
History and Future of Hydrocolloids in the Food Industry
Hydrocolloids have a long history in the food industry. These colloidal substances react to water in distinct ways. Depending on whether or not they're water soluble, they can be added to foods to produce various types of gels and coatings or act as thickening agents. Hydrocolloids have been used for over a century as major ingredients to improve the value of processed foods and beverages. Most of these ingredients were introduced into the industry in close proximity and their production continues to increase.
As the food industry continues to move forward, advancements in technology are impacting the application of hydrocolloids and other ingredients commonly added to food systems. For instance, the recent phenomenon of 3D printing is drastically changing the way manufacturers and individuals choose to source products. One university experimented with hydrocolloids to produce 3D printed edible ingredients such as batters, dough, chocolate, sugar, and candy. Using the versatility of hydrocolloids and the convenience of a 3D printer, we may be able to enhance the food industry in new ways.
Hydrocolloids Available From Brenntag
Brenntag offers safe and innovative food and nutrition ingredients for our North American customers. We've become one of the top food additive distributors because we know how important it is that the final form of every processed food has the exact taste, texture, shelf-life, and presentation that you desire. All of our ingredients are developed and tested in-house by experts who know how to use reliable methods to produce optimal results.
Our selection of hydrocolloids include:
|Carboxymethyl Cellulose||Gum Tragacanth||Pectin|
|Carrageenan||Hydroxypropyl Cellulose and Hydroxypropyl Methylcellulose||Propylene Glycol Alginate|
|Guar Gum||Locust Bean Gum||Sodium Alginate|
|Gum Arabic||Methyl Cellulose||Xanthan Gum|
Together, we'll use our extensive knowledge to help you choose the right ingredients for your products. We'll provide you with naturally derived and certified organic hydrocolloid ingredients that you can apply to your baked goods, beverages, confectioneries, dairy products, grain products, meats and seafood, dressings and sauces, and other processed or packaged foods. We meet all HACCP food safety regulations and adhere to all ISO standards.
Speak with a team member
As a proud part of the Brenntag Group, Brenntag North America has been a leader in ingredient distribution across North America since our establishment in the 1970s. Since then, we've continued to innovate the way we source and produce our high-quality food additives. Allow us to help you select the right hydrocolloid combinations that will improve the look, feel, value, and lifespan of your food or beverage. To learn more about our other hydrocolloid ingredients, speak with one of our knowledgeable representatives today.