Fructose is a natural sugar that has various properties, including that of keeping blood sugar levels under control and avoiding laxative effects. Let’s find out better.
What is fructose
Fructose (or levulose) is a monosaccharide, that is a simple sugar, which has the same molecular formula as glucose (C6H12O6) but different chemical structure and therefore has very different characteristics due to some differences in the bonds between the various atoms.
Fructose is the main sugar in fruit and honey, and is also present in many vegetables. Fructose is found in sugary fruit and honey, but is also found in some vegetables. Sugar chard and sugar cane also contain small amounts.
Fructose is the sweetest of all types of sugars. The sugar we normally use is sucrose, made up of one glucose and one fructose molecule. The latter, however, can also be refined and reduced to small crystals to be used as a sweetener.
Main functions of fructose
Fructose is absorbed in the intestine, sent to the liver through the bloodstream and here it is transformed into glucose. In turn, glucose is deposited in the form of glycogen.
Fructose is converted into glucose because it is the most easily usable form in the liver and cell. The absorption of fructose is lower than that of glucose, this characteristic is very important both to keep glycemic values under control and to avoid laxative effects.
Fructose is in fact a molecule that recalls water and in contained doses it does not produce laxative effects as can happen with other sweeteners.
Where is it
Foods that contain the highest amount of fructose are tomatoes, bananas and ripe grapes.
The fructose found on the market can be natural, derived from fruit waste, or chemical, that is, obtained from the glucose present in corn starch.
Fructose is found in various packaged foods such as candies, breakfast cereals, sweets and diet foods, in which it is inserted in the form of corn syrup that contains it for 45%.
Fructose has a high hygroscopicity, that is, it tends to absorb water from the surrounding environment. Its use is also aimed at preserving food as it prevents the formation of mold.
At room temperature, fructose is found in liquid form. However, through the refining process it is possible to obtain white crystals similar to sugar. Being contained in good quantities also in common honey and fruit, it can be taken in sufficient quantity for the daily requirement even just by consuming these foods.
Contraindications of fructose
Among the possible contraindications of fructose, there is a pathological condition called fructosuria, characterized by the presence of fructose in urine and blood. It can result from an excessive intake of fructose, but also from dysfunctions of the hepatic and intestinal metabolism.