Classification of Carbohydrates
It ranks carbohydrates according to their glycemic index that is to say according to their hyperglycaemic effect. Indeed, if all the carbohydrate source is glucose, they do not increase blood glucose equivalent. Overall, the simple carbohydrates tend to raise blood sugar quickly, as the complex carbohydrates it varies.
The glycemic index (GI) of food used to evaluate the rate of absorption of the glucose.
To calculate a GI is given to volunteers 50 g glucose dissolved in water (glucose is the carbohydrate of reference, you can also take the starch in white bread). Blood glucose is then measured every 30 minutes for 2 to 3 hours. This operation is repeated with a portion of the test food containing 50 grams of carbohydrates. By dividing the area under the curve of blood glucose test food by the area under the curve obtained with glucose, we obtain the IG. Below 55 we talk about low GI between 55 and 70 IG moderate and over 70 high GI. More GI of a food is, the more it increases rapidly and the brutal blood sugar.
Carbohydrates What’s the Point?
The main function of carbohydrates is to provide energy. They release 4 kcal / g. The human body uses carbohydrates as glucose (all carbohydrates we eat are converted to monosaccharides during digestion to pass into the blood. Assimilated monosaccharides other than glucose are then converted into glucose by the liver).
Glucose is distributed in the body to be directly used by all cells (muscle, heart ) and especially nerve cells. Glucose is the sole source of energy in the brain (the latter can not utilize fat for this purpose). For this reason, the blood glucose (or glucose) must be maintained above a minimum level.
Glucose can also be converted into glycogen, a polysaccharide similar to starch, which is stored in the liver and muscles and provides an energy reserve immediately available.
The fibers are not treated, they do not provide energy. However they have an important role in the mechanical action of digestion. They increase the volume of stool and stimulate transit.
Sources of Carbohydrates
Carbohydrates are found in many foods. They are found mostly in foods of plant origin. There was very little in foods of animal origin except for milk which is a source of lactose.
Simple carbohydrates
Glucose is rarely encountered in this simple form in nature. Fructose is naturally present in fruits, corn, honey. Sucrose is composed of one molecule of glucose and one fructose molecule. This disaccharide is a carbohydrate reserve of plant species such as sugar beet or cane sugar. It is the white sugar, our table sugar. Lactose is composed of one glucose and one galactose molecule: the milk sugar. The maltose present in the malt combines two molecules of glucose.
Carbohydrate Derivative Compounds
Fructose Ketohexose, is Cyclized by reaction between carbon 1 and 4, this form is derived from furan, furan is the form (Figure 3). Glucose but also the D-glucofuranose is not stable and is rapidly becoming D-glucopyranose. The dare is cyclizing furan form (furanose) are:
- The ribose giving ribofuranose.
- The 2-deoxyribose 2-giving desoxyribofuranose.
- Fructose giving fructofuranose.
- Generally, it is Ketohexose.
The dare is cyclizing pyran form (Pyranose) are:
- Glucose giving glucopyranose.
- Galactose giving galactopyranose.
- Generally, it is Aldohexose.