File Name: different types of sugar and their uses .zip
This is a list of sugars and sugar products. Sugar is the generalized name for sweet, short-chain, soluble carbohydrates , many of which are used in food. They are composed of carbon, hydrogen, and oxygen.
Today we are diving in deep into the sweet stuff, sugar! When we think about how ingredients function in baking, sugar is the first one that comes to my mind. And while we all know the obvious function of sugar in baking, that it makes things sweet, it actually serves many other functions. This lesson is not going to go in depth about alternative sugar such as liquid sweeteners, and sugar substitutes, rather it will focus on traditional sugar in its many forms and how it functions in baking.
The Function of Sugar in Baking
Carbohydrates are a third major group of biomolecules. This diverse group is commonly described as sugars, or saccharides, from the Greek word for sugar. The simplest carbohydrates are called monosaccharides, or simple sugars.
An example is glucose. Monosaccharides can be joined to make larger molecules. Disaccharides contain two monosaccharides. Sucrose is a disaccharide, containing both fructose and glucose. Polysaccharides are chains of many sugar subunits. Examples include glycogen and cellulose, both of which are polymers of glucose but with different configurations. Not all sugars have this formula, however. Carbohydrates are important in cells as energy sources glucose, glycogen, amylose , as markers of cellular identity oligosaccharides on the surface of cells of multicellular organisms , as structural components cellulose in plants , and as constituents of nucleotides ribose in RNA, deoxyribose in DNA.
The most common monosaccharides include glucose, fructose, galactose, ribose, and mannose. Of these sugars, all but one fructose exists as an aldehyde. Fructose and other less well known sugars are ketones. Figure 2. Some discussion of nomenclature is appropriate. Other descriptive nomenclature involves use of a prefix that tells how many carbons the sugar contains.
For example, glucose, which contains six carbons, is described as a hexose. The following list shows the prefixes for numbers of carbons in a sugar:. Other prefixes identify whether the sugar contains an aldehyde group aldo- or a ketone keto- group. Prefixes may be combined. Glucose, which is a 6-carbon sugar with an aldehyde group, can be described as an aldohexose. The list that follows gives the common sugars and their descriptors.
Sugars may have multiple asymmetric carbons and thus differ from each other in the configuration of hydroxyl groups on asymmetric carbons. Two sugars having the same chemical form aldoses, for example and the same number of carbons, but that differ only in the stereochemical orientations of their carbons are referred to as diastereomers Figure 2.
For example, glucose, galactose, and mannose all have the formula of C6H12O6, but are chemically distinct from each other in the orientation of hydroxyl groups around the carbons within them. If two sugars are identical except for having one hydroxyl configured differently such as images glucose and galactose - Figure 2. If the configuration of all of the hydroxyls of one sugar is exactly the opposite of their configuration in another sugar, the two sugars are mirror images of each other Figure 2.
Mirror images of sugars are known as enantiomers. Please note that due to the way sugars are named, L-glucose is the mirror image of Dglucose.
Movie 2. Sugars with five and six carbons can readily cyclize Figure 2. This carbon has a special name - it is called the anomeric carbon and like the other asymmetric carbons in sugars it can have the hydroxyl in two different positions.
Sugars cyclizing to form rings with five atoms in them see fructose in Figure 2. The carbonyl carbon beomces the anomeric carbon in the ring by binding to the oxygen of a hydroxyl elsewhere in the chain. Most pentoses and hexoses can form both furanose and pyranose structures Figure 2. Orbitals of carbon prefer to be in tetrahedral conformations and this means that the bonds between carbons in a ring do not lie flat.
Some of these forms resemble boat structures, which others resemble chairs or envelopes Figure 2. The stablest and thus most abundant of these forms have all of the hydoxyls in the equatorial positions, resulting in less steric hindrance.
Locations of glycosidic carbon indicated with red asterisks. All are glycosides except N-acetylglucosamine. Many modifications can occur on sugar residues Figure 2. Common ones include oxidation, reduction, phosphorylation, and substitution of an amine or an acetylamine for a hydroxyl. The ones that affect the anomeric hydroxyl group make glycosides Figure 2.
The last considerations for simple sugars relative to their structure are their chemical reactivity and modification. Most monosaccharides are reducing sugars. This includes all of the common ones galactose, glucose, fructose, ribose, xylose, and mannose. Some disaccharides, such as lactose and maltose are reducing sugars since they have at least one anomeric carbon free, allowing that part of the sugar to linearize and yield an aldose.
Sucrose, on the other hand has no anomeric carbons free - both are involved in a glycosidic linkage, so they cannot linearize and thus it is not a reducing sugar. Oxidation and reduction of sugars can occur in cells.
As we will see, phosphorylation of sugars occurs routinely during metabolism. One oxidation product of glucose is glucuronic acid, a six carbon molecule where the CH2OH on carbon six is oxidized to a carboxylic acid Figure 2. Related oxidized sugars include galacturonic acid and mannuronic acid. In addition, glucuronic acid is made from a UDP-glucose precursor. Glucuronic acid is a common constituent of glycosaminoglycans, proteoglycans, and glycoglycerolipids.
Glucuronic acid is found in heparin, dermatan sulfate, chondroitin sulfate, hyaluronic acid, and keratan sulfate. Glucuronic acid is also a precursor of ascorbic acid Vitamin C in organisms that synthesize this compound. Reduction of aldoses or ketoses by hydrogenation produces the corresponding sugar alcohols. The compounds are widely used as thickeners of food or as artificial sweeteners, due to their ability to stimulate sweet receptors on the tongue.
Common sugar alcohols sugar progenitor in parentheses include glycerol glyceraldehyde , xylitol xylose , sorbitol Figure 2. Most of these compounds have a sweetness of between 0. Xylitol is the sweetest of them with a sweetness equal to that of sucrose. Sugar alcohols are used sometimes to mask the aftertaste of other artificial sweeteners.
Many of them also produce a cooling sensation upon dissolving, due to that being an endothermic process for them, resulting in a pleasant mouth sensation. Last, they are poorly absorbed by intestines, and so have a low glycemic index. Artificial sweeteners are compounds that stimulate taste receptors for sweetness, but are metabolized for energy inefficiently at best. Seven such compounds are approved for use in the U. The sugar alcohol known as sorbitol is also sometimes used as an artificial sweetener.
Disaccharides Figure 2. The most common ones include sucrose glucose and fructose , lactose galactose and glucose , and maltose glucose and glucose. All of the common disaccharides contain at least one glycosidic bond see HERE. We name the disaccharides according to which carbons are linked to each other and the how the anomeric carbon of the glycosidic bond is configured. As their name implies, oligosaccharides Figure 2.
These often, but not always contain modified sugars. Unlike all of the other saccharides, oligosaccharides are not typically found unattached to other cellular structures. Instead, oligosaccharides are found bound, for example, to sphingolipids making cerebrosides or gangliosides or proteins making glycoproteins. The patterns of oligosaccharides displayed on the extracellular face of the plasma membrane acts as a sort of barcode that identifies specific cell types.
The immune system recognizes these identity tags in the body. While this provides a very good defense against invading cells of an organism, it also can pose significant problems when organs are transplanted from one individual into another, with rejection of donated organs, in some cases.
The oligosaccharides that are attached to proteins may also determine their cellular destinations. Improper glycosylation or errors in subsequent sugar modification patterns can result in the failure of proteins to reach the correct cellular compartment.
For example, inclusion cell disease also called I-cell disease arises from a defective phosphotransferase in the Golgi apparatus.
This enzyme normally catalyzes the addition of a phosphate to a mannose sugar attached to a protein destined for the lysosome. In the absence of a functioning enzyme, the unphosphorylated glycoprotein never makes it to the lysosome and is instead exported out of the cell where it accumulates in the blood and is excreted in the urine.
Individuals with Icell disease suffer developmental delays, abnormal skeletal development, and restricted joint movement. Sugars are commonly attached to proteins in a process called glycosylation. Typically the attachment is to a hydroxyl or other functional group. The majority of proteins synthesized in the endoplasmic reticulum are glycosylated. Five classes of glycosylated products called glycans if multiple carbohydrates are attached via glycosidic bonds are known.
They include:. Some proteins require glycosylation to fold properly or to be stable. Glycosylated proteins on the plasma membrane serve as cellular identifiers. Blood types, for example, arise from differential glycosylation of a blood cell membrane protein.
Glycosylation can also play an important role in cell-cell adhesion - important in the immune system. N-linked protein glycosylation is one of five different types of protein glycosylation and it is the most common type of such alteration. The process occurs commonly in eukaryotic cells, in some archaean cells, and rarely in bacteria. The structure of glycans varies a bit by protein and it also varies by the cell and by the organism.
Bonds between the sugars of the glycan are glycosidic involve anomeric carbon and usually occur between carbons one and four. The process of making an N-linked protein occurs in three steps.
2.7: Structure and Function- Carbohydrates
Consuming too much sugar is not healthy, and at the end of the day, it makes us crave sugar even more. People face sugar addiction and may not even realize it. Most of the time it can be avoided. Continually feeding your body sugar even without knowing it only makes you crave sweets even more…. And your relentless sweet tooth is keeping you from losing weight, getting healthy and feeling comfortable in your own skin. Well, understanding how sugar disguises itself in your everyday food and how it affects your body is the first step in getting rid of it for good! In my 7-Day Sugar Detox for the 17 Day Diet , I go through the exact steps on how to get rid of your sugar cravings by understanding how sugar is hiding in your every day food.
When you brew a cup of hot tea, do you reach for honey or sugar? Although both may add sweetness to your drink, their nutritional benefits vary. Honey and sugar are both carbohydrates composed primarily of glucose and fructose. Both can result in weight gain if overused. So which is healthier? Bees use the nectar they collect from flowers to create honey. This thick substance is typically consumed in liquid form and can range in color from pale yellow to dark brown.
Sugar is not only a sweetener, but it als o plays a vital role in the development of taste, texture, and appearance of baked goods. Learn about the common types of sugar in baking and their uses. Yes, sugar makes things sweet. But in the world of baking and cooking, it also has a lot of other roles to play. It can stabilize, add texture, act as a leavening agent and affect the flavor of a variety of baked goods. Sugar can come from various natural sources and exists in two forms:.
Find, read and cite all the research you need on ResearchGate. This article views types of sugars, their functions in food and their effects on.
List of sugars
Sugar is the generic name for sweet-tasting , soluble carbohydrates , many of which are used in food. Table sugar , granulated sugar , or regular sugar , refers to sucrose , a disaccharide composed of glucose and fructose. Simple sugars, also called monosaccharides , include glucose , fructose , and galactose. Compound sugars, also called disaccharides or double sugars, are molecules composed of two monosaccharides joined by a glycosidic bond. In the body, compound sugars are hydrolysed into simple sugars.
Carbohydrates are the main source of energy for the body. They are the sugars, starches, and dietary fiber that occur in plant foods and dairy products. Carbohydrates are mainly found in plant foods.