Common Cooking Sugars & Carbohydrates Common sugars, glucose, fructose and sucrose, are also carbohydrates--fuel for our bodies. They are made up of carbon (“carbo-“), hydrogen (“hydr”) and oxygen, and in fact, they share the same chemical formula, C6H12O6. Carbohydrates are produced by ALL living things (plants and animals) for the storage of energy. And let's face it: We need carbs to function. They provide the energy for our brains, for our muscles, for our cardio-vascular system. Common sugars are the most concentrated source of carbs, or energy, we have, second only to fats and oils. Plants and animals, including, of course, humans, put these carbs to use in two ways: Storage of chemical energy in the form of calories  (4 cal/gram) Building blocks for our cells. Carbs sometimes get a bad rap. They shouldn't. They are important to our bodies' function. Carbs in balance are not a problem, per se; carbs out of balance are a big problem. Lately some people have been eating more synthetically produced carbs than their bodies can use. The excess is stored as fat.   Sugars in the Kitchen While sugars offer us so much in biochemical terms, we most often think about sugars as sweet things that make every day better. Sweetness helps mask undesirable flavors (it was used to administer medicines during the Middle Ages). It also enhances our perception of food aromas, perhaps by signaling to the brain that the food is a good energy source. “This is why we have taste receptors that register the presence of sugars, and why our brain attached pleasure to that sensation: sweetness is the sign of a food that can help supply our need for calories.” As noted by Harold McGee in On Food & Cooking: The Science and Lore of the Kitchen. Besides providing energy to our bodies and sweetening the foods we eat, sugar provides texture as well.  It forms a sticky matrix that binds food particles together. It has a strong affinity for water, it dissolves easily and bonds quickly to water molecules so it helps keep baked good moist. It helps tenderizes flour's gluten in baked goods and softens proteins in custards and creams. When heated (or caramelized), it changes color as it changes in flavor--from pale and sweet, to browner and acidic, to darker and bitter, adding visual and olfactory appeal.   The Common Sugars: Glucose, Fructose & Sucrose Glucose: Simple sugar or monosaccharide/C6H12O6 (aka: dextrose) Living cells get most of their energy from glucose. It's a basic building block for starches and is commonly derived from corn and rice, but it's also in many fruits and honeys. It's ALWAYS in combined with other sugars (especially fructose). Alone, glucose metabolizes quickly, flooding the system with energy, then dissipating. (Some folks experience this as a blood sugar spike.) When glucose is combined with other common sugars, the other sugars help sustain its benefits. Compared to other common cooking sugars (sucrose and fructose), glucose: Is the least sweet Is slow to taste sweet, peaks at about half the sweetness of sugar and lingers. Is less soluble in water Produces a thinner solution Caramelizes at 300° F/150°C Crystallizes, given enough time and the right temperature Fructose: Simple sugar or monosaccharide/C6H12O6 Fructose, the common sugar, is vastly different from the manufactured high fructose corn syrup we've heard so much about lately. Like glucose, fructose is found in many fruits and honey. Fructose has the same chemical formula as glucose, but it's organized differently, and that makes all the difference. Most importantly, fructose metabolizes slowly, providing a “timed release” of energy. Compared to other common cooking sugars fructose: Is the sweetest of the common sugars  Our tastebuds recognize its sweetness quickly and strongly, but it fades quickly without a lingering aftertaste Is most soluble in water (4 parts fructose will dissolve in 1 part water) Begins to caramelize at 220° F/105° C  Doesn't crystallize when it's the dominant common sugar. Fructose’s sweetness varies depending on temperature. Its structure actually changes when heated or cooled. It’s sweetest in cold solutions, but only about half as sweet in warm solutions (140° F/60° C). Sucrose: Compound sugar or disaccharide/Glucose+Fructose (a.k.a table sugar) Green plants produce sucrose in the process of photosynthesis and it's found in sugar cane and sugar beets. Sucrose offers us the most useful combination of properties: It's not as sweet as fructose, but sweeter than glucose It's less soluble than fructose, but more soluble than glucose It takes just a bit of time for our tastebuds to detect sucrose's sweetness, then we enjoy the flavor a little longer 2 parts of sucrose can dissolve in 1 part water (Produces the most viscosity or thickness in a water solution) Begins to melt at 320°F/160°C and begins to caramelize at 340°F/170°C   Measuring Carbs' Effects: the Glycemic Index Glycemic Index is a ranking system for carbohydrates based on their effect on blood glucose levels. The glycemic index of a food is a measurement of the changes in our bodies' blood sugar in the two hours after we eat something. Foods that metabolize quickly, flooding our system with carbs/energy, are generally referred to as high glycemic foods; food that metabolize slowly are low glycemic foods. Low GI foods generally offer our bodies a more sustained, slow release of carbs/energy. (Some believe that low GI foods are especially useful for people monitoring their blood sugar.) The Glycemic Index is a general guide rather than an absolute reference, and is often reported as a range rather than a fixed number. While the Glycemic Index suggests a certain food's effect on our system, it is influenced by other foods already in our system and our individual metabolic rate (we all metabolize things differently). Each of us will have a different glycemic response to a food. Glycemic comparisons (Relative comparisons of sweeteners using glucose as 100 points)  Sugar   Glycemic Index (+/-)   Glucose   100   Honey* (glucose & fructose)     68   Sucrose     68  Fructose     20 *This is a general reference. Honey is a combination of sugars. Some honeys are mostly sucrose; others are evenly divided among sucrose, fructose and glucose; others are mostly fructose—especially sage honey and tupelo honey. Honey’s GI varies considerably based on the bees' forage. Sugar Substitutes Our three common cooking sugars--fructose, sucrose and glucose--all combine useful properties in one single ingredient that provides energy/calories, sweetness, substance and structure, moisture, binding and the ability to caramelize. However, some cooks and manufacturers need just one or two of these attributes; work has been going on for years to isolate sugars' different properties. The most sought-after attributes are: Bulking abilities Stabilizing blood sugar Supplying fewer calories Sugar Substitutes and their origins (modified variations on naturally occurring sucrose, glucose, fructose) If we considered table sugar as the baseline with a sweetness level of 100, a sweetness level of 50 is half as sweet as sugar, and a level of 500 is five-times sweeter. Ingredient   Relative Sweetness    Original Source    When Commercialized  Sucrose   100    Sugar cane & beets   traditional  Corn Syrup (traditional)   40    Starches (potato & corn)    1840s  Saccharin   30,000    Coal tar/synthetic   1880s Aspartame   18,000   Modified amino acids    1970s  Xylitol   100  Fruits & vegetables    1970s  High Fructose Corn Syrup   100    Synthetically modified corn syrup   1970s Stevia*   30,000   South American native plant    1970s Sorbitol   60     Fruits   1980s  Erythritol    70    Fruits & vegetables, fermented foods    1990s  Sucralose    60,000    Chemically modified sucrose    1990s  Neotame    800,000   Modified aspartame    2000s  (*Stevia is not certified as a sweetener by the FDA; it is considered a supplement) High-Intensity Sweeteners High intensity sweeteners are just what they describe--they are many, many times sweeter than sugar (sucrose). Just a little goes a very long way and and the metabolic impact of the carbohydrates is often nil. The sensation of sweetness caused by high-intensity sweeteners (the "sweetness profile") is sometimes notably different from sucrose so the high-intensity sweeteners are used with other bulking agents or sugar alcohols) in combinations that offer the most natural sweet sensation. Bulking agents in the market today include many low calorie/no calorie sugar alcohols or polyols. Sugar Alcohols According to a 2004 Calorie Control Council survey, 84% of us (or 180 million consumers) use low-calorie, reduced-sugar and sugar-free foods and beverages. A number of these products contain polyols or sugar alcohols, especially sugar-free gum, candy, ice cream, frozen desserts and baked goods.  What are Sugar Alcohols?  They are neither sugar nor alcohol, but group of low calorie, carbohydrate-based sweeteners. Some occur naturally (especially erythritol), others are synthetic. They deliver the taste and texture of sugar with about half the calories. They are used as a food ingredient, often to replace sugar, cup for cup, in many sugar-free and low-calorie foods. The are often combined with small amounts of high-intensity sweeteners such as aspartame, neotame, saccharin or sucralose. Polyols are used in foods such as sugar-free chewing gums, ice cream, candies, frozen desserts and baked goods. In addition to mild sweetness, polyols provide the bulk and texture of sugar in food products. They promote dental health: The FDA approved the use of the health claim "does not promote tooth decay" for sugar-free products containing polyols, including Organic Erythritol. The American Dental Association issued a position statement that sugar-free foods do not promote tooth decay. They are low in calories: Since polyols are only partially absorbed (rather than metabolized like common sugars)by the body, they have fewer calories than sugar. Polyols range from 0.2 to 3 calories per gram, compared to sugar with 4 calories per gram. That's why foods made with polyols provide sweetness with fewer calories. They have a low dietary impact: According to diabetes management guidelines, if all the carbohydrate in a food is from polyols and the total carbohydrate is less than 10 grams, it is considered a "free food." They have a low glycemic effect: Polyols have a lower rate of digestion and absorption than sugars. This results in a lower rise in blood glucose and insulin levels than sugars and other carbohydrates. And sometimes they cause very upset tummies. Because some sugar alcohols are prone to fermentation in the lower gut, some people suffer from unpleasant side effects...