These are the substances that sweeten food, beverages, medications, etc., such as sugar, saccharine or other low-calorie synthetic products. They in general can be termed as sweetening agents. They all are called artificial sweetenrs as thy are usually not a component of the product they are added to. As per the source, these substances can be classified as natural and artificial sweeteners.
Natural sweeteners are obtained from the natural sources like sugarcane and sugar beet and from fruits (fructose) and the artificial ones have a chemical origin. Artificial sweeteners are further of two types namely non-caloric sweeteners and sugar alcohols.
Noncaloric sweeteners do not add calories to foods. They are used in snack foods and drinks. Sweeteners like saccharine and aspartame fall under this category. Sugar alcohols are used in chewing gums and hard candies and have almost same calories as sugar. Examples of sugar alcohols are sorbitol and mannitol.
Acesulfame K - It is a 0 calorie sweetener, 130- 200 times sweeter than sucrose. It is not metabolized by the body. The only limitation it has is that if used in large quantities, it has an after taste. It is used in fruit preserves, dairy products and all types of beverages. It is used to reduce the calories of the products. It is heat resistant and enhances flavors.
Aspartame - It is a low calorie sweetener about 200% more sweet than the sugar. It is disintegrated into aspartic acid, fenylalanine and methanol in the body on digestion. It's taste is similar to sugar only more sweet. It is used in all types of foods and beverages and medicines. It is found naturally in protein rich foods.
Cyclamate - This is a calorie free sweetener 30-50 times sweeter than sugar. It is metabolized in the gut by few individuals and generally expelled as such. It is generally used in combination with other sweeteners. It has a pleasant taste, and is stable at high temperatures and is economical.
Saccharin - It is one of the earliest low calorie sweeteners that is 300-500 times more sweet than sugar. It doesn't metabolize and absorption is slow. Owing to this it is expelled as such from the body. Saccharin is the most widely used sweetener. It was earlier banned in certain countries but now is used quite commonly.
There are other sweeteners like Stevioside, Alitame, Thaumatin, Sucralose, Neohesperidine DC and Aspartame-Acesulfame Salt. All artificial sweeteners have been approved by the U.S. Food and Drug Administration (FDA). They are considered harmless if taken in limited quantities.