Glucose is what is known as an aldohexose, meaning that it contains a compound called an aldehyde, located at the first position in the molecule. Aldehydes have a carbon atom which is attached to a hydrogen atom and also double bonded to an oxygen atom.
Fructose, on the other hand, is a ketohexose, containing a ketone which consists of a single carbon atom double bonded to an oxygen atom.
The ketone in fructose is attached to the second position in the molecule. Ketones play an important role in biochemistry. The simple structures of these sugars allow them to be linked in a number of different ways to other molecules, creating more complex sugars which will behave differently in the body and generating some extremely unwieldy chemical formulas. For consumers, the important thing to remember is that labels which say "dextrose" really mean "glucose.
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In comparison to sugar, they promote browning and are not as sweet. Bakers use dextrose or glucose syrup in biscuits, breads, rolls, cakes, cookies, crackers, doughnuts and frostings. Download our latest paper. Glucose Also known as dextrose or corn sugar What is Glucose? Glucose is a syrup, most often sourced from hydrolyzed corn in the United States and is often called corn syrup. Dextrose, on the other hand, is a powder, purer and sweeter. Glucose and dextrose are available in different forms which affords flexibility for the baker.
Types Codex specifications describe the different types of glucose and dextrose available. Glucose syrup has a dextrose equivalent content of not less than Dried Glucose syrup: Glucose syrup from which the water has been partially removed to give a total solids content of not less than Function In addition to sweetening, some of the key functions of dextrose for bakers are to: Affect dough viscosity Depress freezing points of products Control crystallization in icings and glazes Promote fermentation Affect texture Promote tenderness Act as a reducing sugar for browning and flavor development via the Maillard reaction Nutrition Glucose is a carbohydrate source of energy, supplying 4 calories per gram.
Application Dextrose or corn syrup is not a direct substitute for sugar and work best in baked goods when combined with other sugars. Accessed 15 Feb. Corn Refiners Association. Accessed 5 April One Comment. Kenneth Ali December 11, at pm - Reply. First, the higher viscosity promotes crystal melting and attrition. Second, the solution has a higher resistance to water diffusion movement of melted liquid from smaller ice crystals to the surface of larger ice crystals at higher concentrations of sweetener Haddad Amamou et al.
When a substance is dissolved in water, however, the temperature at which the water freezes is lowered. Freezing point depression is influenced primarily by sweeteners including the lactose in milk and milk salts. Increasing the amount of these solutes will lower the freezing point of an ice cream mix, resulting in less ice being formed at a given temperature. Different sweeteners depress the freezing point of water to different extents, depending on the number of small molecules in the mix.
The lower the molecular weight of a sweetener, the greater the effect it will have on lowering the freezing point. Dextrose and fructose, having nearly half the molecular weight of sucrose, will be twice as effective at lowering the freezing point than an equivalent weight of sucrose.
Freezing point depression affects the rate of recrystallisation during static freezing, the softness and scoopability of ice cream, and the rate at which ice cream melts during consumption.
This increase in crystal size eventually reaches a point where the ice cream develops coarse texture, at which point it has surpassed its shelf life.
This is because as the freezing point is depressed, the amount of unfrozen water increases, and this unfrozen water will participate readily in recrystallisation during storage. These findings were attributed to the greater freezing point depression caused by HFCS Ice cream made with either dextrose or fructose will have a higher melting rate because of a lower freezing point, whereas ice cream made with maltodextrin or 20 DE CSS will have a slower melting rate because of a higher freezing point.
Sweeteners are also responsible for the softness and scoopability of ice cream through their effect on freezing point depression. Corn syrup products with a lower molecular weight will generally produce soft ice cream owing to a low freezing point and the subsequent reduction in the ice phase volume the amount of frozen water.
Ice cream made with maltodextrin or 20 DE CSS, which both have a high molecular weight, will likely have a high freezing point and hard texture. If sucrose is replaced with either dextrose or fructose, the freezing point is likely to be low, resulting in less frozen water and softer ice cream. Smooth and creamy texture, primarily associated with a high milk fat content and small ice crystal size, is also strongly influenced by the viscosity of the ice cream mix Mela et al.
Viscosity can be loosely defined as the thickness of a liquid, with thicker liquids having higher viscosities honey has a higher viscosity than water for example. In general, as the viscosity of an ice cream mix increases, the smoothness of texture, body, and resistance to melting increases, but the amount of air, or overrun, decreases Marshall et al. The viscosity of a mix increases with increasing concentration of stabiliser, protein , corn syrup, fat, and total solids, with the contribution of each decreasing in that order i.
Maltodextrins and Low DE corn syrups are very viscous due to the higher sugars they contain. When added to an ice cream mix, they will add body and increase mix viscosity. Because high DE syrups contain very few higher sugars, they will have a minimal effect on increasing the viscosity of an ice cream mix. Similarly, Ozdemir et al. The viscosity of an ice cream mix also plays an important role in the stability and size of air bubbles. During dynamic freezing, t he small, newly formed air bubbles are not stable and need to be stabilised to prevent coalescence.
It is important to minimise this coalescence since smaller dispersed air cells produce a creamier mouthfeel during consumption Eisner et al. The addition of corn syrups enhances the stability and reduces the size of air bubbles through their effect on increasing the viscosity of the ice cream mix.
This makes maltodextrins and low DE syrups, with their viscosity enhancing ability, ideal for ice cream production. Ice crystal size is related inversely to the total solids the fat, milk solids-not-fat, sweetener, egg yolk solids, stabiliser, and emulsifier of an ice cream mix; that is, ice cream made from a mix with a higher total solids content generally contains smaller ice crystals Donhowe et al.
The theory behind this is that an increase in the level of total solids in the mix will lower the amount of water and thereby reduce the total amount of ice formed. Because of their low sweetness value, maltodextrins, corn syrup 20 to 64 DE , and maltose, are a convenient and cost-effective way of increasing total solids without introducing excessive sweetness. Corn syrups are nutritive sweeteners produced by the partial hydrolysis of corn starch.
As the DE of a syrup increases, so too does its sweetness, flavour enhancement, and effect on freezing point depression, but its viscosity, ability to enhance smoothness and creaminess, contribution of body, mouthfeel, and solids, air bubble stabilisation, and ability to increase the shelf-life of ice cream during storage decrease. Maltodextrins and low DE corn syrups have very little sweetness, produce a firmer and chewier ice cream that melts slowly, reduce the rate of recrystallisation during storage, thus increasing shelf life, and promote the formation of small ice crystals and air cells through their viscosity-enhancing properties and contribution to total solids.
Excessive use of maltodextrins or low DE corn syrups, will, however, generally mask or reduce the perception of flavour. Dextrose is the ultimate end product of starch hydrolysis.
With further enzyme processing, dextrose can be converted to fructose, as in the production of high fructose corn syrups. Both dextrose and fructose syrups contribute sweetness, enhance flavour, especially fruit flavours, and produce a softer ice cream that is easier to scoop but melts faster.
Excessive use of dextrose or fructose will likely result in excessive sweetness, a soft ice cream that melts too quickly, and an increased rate of recrystallisation during storage, which will limit the shelf life of the ice cream. I hope this review of corn syrup products helps. Do feel free to get in touch with any questions or suggestions on how this post can be improved.
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