Everything about Sucrose totally explained
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| Solubility of Pure Sucrose |
| Temperature(C) | g Sucrose/g Water |
| 50 | 2.59 |
| 55 | 2.73 |
| 60 | 2.89 |
| 65 | 3.06 |
| 70 | 3.25 |
| 75 | 3.46 |
| 80 | 3.69 |
| 85 | 3.94 |
| 90 | 4.20 |
Sucrose (common name:
table sugar, also called
saccharose) is a
disaccharide (
glucose +
fructose) with the
molecular formula C
12H
22O
11. Its systematic name is α-D-glucopyranosyl- (1↔2)-β-D-fructofuranoside (ending in "oside", because it's not a
reducing sugar). It is best known for its role in
human nutrition and is formed by plants but not by other
organisms such as animals.
Physical and chemical properties
Pure sucrose is most often prepared as a fine, white, odorless crystalline powder with a pleasing, sweet taste; the common table sugar. Large crystals are sometimes precipitated from water solutions of sucrose onto a string (or other
nucleation surface) to form
rock candy, a
confection.
Like other
carbohydrates, sucrose has a
hydrogen to
oxygen ratio of 2:1. It consists of two
monosaccharides, α-
glucose and
fructose, joined by a
glycosidic bond between carbon atom 1 of the glucose unit and carbon atom 2 of the fructose unit. What is notable about sucrose is that unlike most polysaccharides, the glycosidic bond is formed between the reducing ends of both glucose and fructose, and not between the reducing end of one and the nonreducing end of the other. The effect of this inhibits further bonding to other saccharide units. Since it contains no free anomeric carbon atom, it's classified as a nonreducing sugar.
Sucrose melts and decomposes at 186 °C to form
caramel, and when combusted produces
carbon,
carbon dioxide, and
water. Water breaks down sucrose by
hydrolysis, however the process is so gradual that it could sit in solution for years with negligible change. If the
enzyme sucrase is added however, the reaction will proceed rapidly.
Reacting sucrose with
sulfuric acid dehydrates the sucrose and forms the element
carbon, as demonstrated in the following equation:
» C
12H
22O
11 + H
2SO
4 catalyst → 12 C + 11 H
2O
Commercial production and use
Sucrose is the most common food
sweetener, although it has been replaced in American industrial food production by other sweeteners such as
fructose syrups or combinations of functional ingredients and high intensity sweeteners. This is due to the subsidization of corn in the United States, which has led to a vast surplus. Combined with sugar tariffs, this has driven the price of
corn syrup far below that of sugar.
Sucrose is the most important sugar in
plants, and can be found in the
phloem sap. It is generally extracted from
sugar cane or
sugar beet and then purified and crystallized. Other (minor) commercial sources are sweet
sorghum and
sugar maples.
Sucrose is ubiquitous in food preparations due to both its
sweetness and its functional properties; it's important to the structure of many foods including biscuits and cookies, cakes and pies, candy canes, ice cream and sorbets, and also assists in the preservation of foods. As such it's common in many processed and so-called “
junk foods.”
Sugar as a macronutrient
In mammals, sucrose is very readily
digested in the
stomach into its component sugars, by acidic
hydrolysis. This step is performed by a
glycoside hydrolase, which catalyzes the hydrolysis of sucrose to the monosaccharides glucose and fructose. Glucose and fructose are rapidly absorbed into the
bloodstream in the
small intestine. Undigested sucrose passing into the intestine is also broken down by
sucrase or isomaltase
glycoside hydrolases, which are located in the
membrane of the
microvilli lining the
duodenum. These products are also transferred rapidly into the bloodstream.
Sucrose is digested by the enzyme
invertase in
bacteria and some
animals.
Acidic hydrolysis can be used in laboratories to achieve the hydrolysis of sucrose into glucose and fructose.
In human nutrition
Sucrose is an easily assimilated
macronutrient that provides a quick source of energy to the body, provoking a rapid rise in
blood glucose upon ingestion. However, pure sucrose isn't normally part of a human diet balanced for good nutrition, although it may be included sparingly to make certain foods more palatable.
Overconsumption of sucrose has been linked with some adverse
health effects. The most common is
dental caries or
tooth decay, in which oral bacteria convert sugars (including sucrose) from food into acids that attack tooth enamel. Sucrose, as a pure
carbohydrate, has an
energy content of 3.94
kilocalories per gram (or 17
kilojoules per gram). When a large amount of foods that contain a high percentage of sucrose is consumed, beneficial nutrients can be displaced from the diet, which can contribute to an increased risk for chronic disease. It has been suggested that sucrose-containing drinks may be linked to the development of obesity and
insulin resistance. However, most soft drinks in the USA are now made with high-fructose corn syrup, not sucrose.
The rapidity with which sucrose raises blood glucose can cause problems for people suffering from defects in glucose metabolism, such as persons with
hypoglycemia or
diabetes mellitus. Sucrose can contribute to development of the
metabolic syndrome. In an experiment with rats that were fed a diet one-third of which was sucrose, the sucrose first elevated blood levels of
triglycerides, which induced
visceral fat and ultimately resulted in
insulin resistance. Another study found that rats fed sucrose-rich diets developed
high triglycerides,
hyperglycemia, and
insulin resistance.
Further Information
Get more info on 'Sucrose'.
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