Thickening agents, or thickeners, are substances that are added to food preparations for increasing their viscosity without changing other properties like taste.
The food thickeners are the modified food starch, polysaccharide or certain vegetable gums. When a food thickener or a thickening agent is added to beverage, it absorbs the fluid and the fluid thickens. Breaking down the starch reverses the thickening action and almost all water in the beverage is available as free fluid for absorption by the body. If the thickening agent is a vegetable gum, it will continue to hold water even during digestion. Thus a vegetable based thickening agent may reduce fluid availability to the body. Commonly used thickening agents are pectin, lignin, algin, gums and agar-agar.
The use of food thickening agents depend upon the type of food and purpose for which you are going to use them. For example, for acidic foods, use of arrowroot as a thickening agent is preferred instead of cornstarch as the later looses the thickening property in acidic food. Some of the food thickeners can be used any time during the cooking of food and some are used close to the final stage.
Flour is a food thickening agent that is used in between the cooking as it needs to be prepared otherwise it will give uncooked taste. For gravies, sauces and stews, Raux is used as a food thickener. Raux is typically made from flour and butter. This food thickener is used while making thick gravy. Egg yolks, nuts, yogurt are some other natural food thickeners that are used as food thickening agents.
Food thickener when used in any food absorbs the fluid to thicken it but does not change the physical or chemical properties of the food. Based on how and from which these are made the food thickeners are classified into two many categories. These are
Polysaccharides as a thickener food includes the starches, vegetable gums and pectin. Food starch is a flavorless powder in which can be included arrowroot, cornstarch, katakuri starch, potato starch, sago, and tapioca.
How to use a food thickener is generally mentioned on the packing. You can thicken the sauces and vegetables by putting the food thickener in them. Now the amount of the food thickeners required actually depends upon the value of thickness needed. Also the property of food thickening agent should be considered to thicken the food. Along with this the way to use the food thickening agent will make the changes. Like all of us use custard powder to make custard that also has the food thickening agent. If you will stir it while cooking then it will be like a sauce. But not stirring it will result into a thick custard that can be sliced like jelly.
You need constant stirring if using flour as a food thickener. If not stirred, lumps will be created that are then very difficult to dissolve. Also before using it first make its mixture in water or liquid you are going to use and then cook it in gravy or food.
Eggs are also used as food thickener for sauces. It is a protein based food thickener so will coagulate giving your sauce or soup a coagulated look.
You can use the thickeners and vegetable gums with all kinds of food colors like natural food color, synthetic food color and lake food colors.
One of the types of food thickeners are gums. All gums are polysaccharides, that is similar to sugars but with many sugar units making up a large molecule. They are bland in taste, odour less and tasteless. They may have a nutritional quality besides the primary function but they certainly help in digestion and may be used as laxatives too. Vegetable gums used as food thickeners include alginin, guar gum, locust bean gum, and xanthan gum.
Vegetable GumsVegetable gums come from the varied sources that can be on land or in sea. Some of the seaweeds are the excellent sources of food gums in which comes the carrageenan and alginates. Whereas guar, locust bean gum, pectin are obtained from the plants. Xanthan gum is obtained by the process of microbial fermentation. The source of gelatin is animal tissue.
As per the definition from Wikipedia Vegetable gums are the polysaccharides that have the natural origin and used to increase the viscosity of the solution or food even if used in a very small concentration.
So vegetable gums are actually the food thickening agents.
Agar Agar Agar agar is used as a vegetable gum for gelling the dairy products like yogurt. Agar agar as a food thickener has the capacity to absorb 100 times more water than its weight. Agar agar is a polysaccharide that has the repeating unit of alpha-D-galactopyranosyl and 3,6-anhydro-alpha-L-glactopyranosyl.
Cellulose Gum Use of cellulose gum as a vegetable gum and food thickening agent is not new. At home homemakers have been using it for the last 50 years. All cellulose vegetable gums are water soluble because of the cellulose content in it. It is used in ice-creams, beverages and in baked food products to prevent stalling. Also the ice-crystal formulation in ice-creams is prevented by this vegetable gum.
Xanthan Gum Xanthan Gum is again a polysaccharide and chiefly used in salad dressing and sauces. Also some of the bakery filling use the Xanthan gum that is an excellent food thickener. This vegetable gum is also used to increase the shelf period of eatables.
Guar Gum Guar Gum is a carbohydrate based vegetable gum and food thickener that swell up in cold water. It is an excellent food thickening agent used in food industry as it has about 80-85% of soluble dietary fibers. Because of this reason guar gum is also used in bread to have more soluble dietary content.
Locust Bean Gum Locust Bean Gum is also called the Carob bean gum as it is made from the carob bean's seed. It is mainly used in food for water binding, thickening and gel strengthening. This vegetable gum is used as dessert gel, dairy applications and as processed cream cheese.
Pectin Pectin is a kind of polysaccharide that is obtained from plant such as citrus fruit peel, apple peel etc. Pectin is a vegetable gum and food thickener that is used to make gel. You will find in almost every fruit based product such as jam, confectioneries, fruit drinks etc. Aprt from this yogurt and other dairy products also use this vegetable gum as food thickener.