A sweetener is a product used to replace sugar. There are two types of sweetener: natural and synthetic. The first is obtained from natural essences as in the case of dextrose, produced through the extraction of fructose from corn. Fructose is also present in fruit, but the costs of the extraction process are very high and therefore it is little exploited.
Other natural sweeteners are mannitol, obtained from the manna extracted from the ash' bark, and sorbitol, which comes from the fruit of the rowan tree.
The synthetic sweeteners all have a high sweetening value, albeit with a low calorie content; saccharin is one of the most popular. Its power is much higher than that of sugar, but unlike the latter it has a bitter aftertaste. Another sweetener is aspartame, widely used in diets.