Posted on 06 Mar 2015 21:09 by EricT
The following is a simple guide to the many different kinds of simple sugars found in prepared and processed foods. All of these sugars contain about the same carbohydrates and deliver the same amount of calories, and so are essentially equivalent to white table sugar. To begin, the basic monosaccharides and dissaccharides important in nutrition are briefly discussed.
Monosaccharides are the simplest form of carbohydrates. They cannot be reduced in size by hydrolosis and so are sometimes called "simple sugars". However, in common usage the term simple sugar usually also includes disaccharides, discussed below, which are two monosaccharides bonded together.
The three main monosaccharides important in human nutrition are glucose, fructose, and galactose. Glucose, a 6-carbon atom, is by far the most abundant monosaccacharide in nature and the most important nutritionally. Fructose is another monosaccharide found in fruits, flower nectar, honey, and the sap of trees. It is a good deal sweeter than glucose. The third simple sugar is galactose, which is a component of "milk sugar", a disaccharide called lactose. Glucose, fructose, and galactose are all classified as a triose, referring to the number of carbon atoms in their saccharide unit (tri- means "three" and -ose means "sugar).
Disaccharides are the most abundant form of the ogliosaccharides, which consist of short chains of monosaccharide units joined by covalent bonds.
Sucrose, which is the disaccharide in white table sugar, is the most important nutritionally, comprising at least a third of the carbohydrate intake in an average diet. It is what most of us are thinking of when we say the word "sugar." and contains equal amounts of bonded glucose and fructose (ß-D-fructofuronasyl-α-D-glucopyronoside). Sucrose contains 5 grams of carbohydrate per teaspoon, delivering about 20 kilocalories.
Lactose, also discussed below and mentioned above is the principal carbohydrate of milk, composed of equal parts glucose and galactose. The third disaccharide is maltose. Maltose, or "malt sugar" is two glucose units linked together. It is produced anytime starch breaks down.
How Is Sugar Made?
White table sugar1, as discussed, is produced from sugar cane or sugar beets. Sugar cane, which is actually a tropical grass2, started being used as a source of sugar thousands of years ago in India, where it was mentioned in writings during the period of 1400-1000 B.C. Although no one knows for sure, it is generally accepted that the plant originally got its start in New Guinea. Modern sugar cane is actually a hybrid of several species of the genus Saccharum.
Sugar beets, which are white rather than red, are another viable sugar crop. They are a much more recent crop for this purpose, having only been introduced as a means for extracting sugar in 1794. Most of the world's sugar comes from sugar cane, however.
Harvested and Cut Sugar Cane
Image by Rufino Uribe via Wikimedia
How Are Sugar Cane and Sugar Beets Refined?
After the sugar cane is harvested, it is washed and then shredded by giant steel rollers, which crush and squeeze the juice from the cane. Water is then sprayed on the crushed plants to get more juice to seep out. Harvested sugar beets are washed, sliced and soaked in vats of hot water to extract the sugar.
The juice from either plant is then heated in evaporation tanks so that it is concentrated into a thick syrup called molasses. Sugar crystals are induced to form so that they can be separated from the molasses by centrifuge. After the "raw" sugar crystals are obtained, the sugar is further processed according to the end product being produced, such as white, turbinado, powdered, or brown sugar.
Harvested Sugar Beets
Image by Hans Hillewaert via Wikimedia
Types of Sugars
The sugars below may give a little less or a little more than the aforementioned 20 Calories but as a consumer you have no way of calculating the difference and even if you could, it would make no difference to your overall diet. Therefore, consider all of them to be the same as white granulated sugar on a teaspoon to teaspoon basis.
Although most of the sugars mentioned below are produced from sugar cane or sugar beets, there are some other sugars mentioned as well because they are sometimes used, or have been used, as ingredients in food manufacturing.
- Brown Sugar: processed white cane sugar to which molasses has been added. It contains varying amounts of sucrose, caramel, and molasses, which are impurities that are originally removed during the refinement of table sugar. Brown sugar can be anywhere from 85 to 95% pure sucrose, depending on how much molasses is added, which is what determines the difference between "light brown sugar" and "dark brown sugar" we are familiar with. Yes, it's a fair guess to say that light brown sugar contains a bit more sucrose than dark brown sugar. But not enough less to make a difference in the diet! See also **[http://www.culinarylore.com/food-science:why-does-brown-sugar-dry-out-and-harden
Why Does Brown Sugar Dry Out and Harden and What Can I Do About It?]**.
- Concentrated Fruit Juice: Used as a sweetener in processed foods, this is a concentrated sugar made from dehydrated and deflavored fruit juice. This sweetener is often used to sweeten products so that they can claim to be "all fruit" or "pure fruit."
- Confectioner's Sugar: Finely powdered granulated white sucrose sugar. Most confectioner's sugar for home use has some corn starch, wheat flour, or calcium phosphate added to keep it free flowing. Also known as icing sugar or frosting sugar.
- Corn Syrup: A syrup, synonymous with glucose syrup , made from maize (corn) via either acid or enzyme hydrolysis. This syrup contains glucose and varying levels of polysaccharides, maltodextrins, etc. It can be hydrolyzed to various degrees up to the point of producing pure dextrose (glucose). Corn syrup comes in various strengths (sweetness) which are determined by the amount of hydrolysis and come in "dextrose equivalents" (DE): 24, 36, and 42 DE. The higher the DE the thinner and sweeter the syrup is. The lower the DE the thicker and more starch-like. Corn syrup is one of several types of "starch hydrolysates" that are popular in the food manufacturing industry.
- High Fructose Corn Syrup (HFCS): Produced from corn syrup (glucose syrup), some of the glucose is isomerized to fructose by the enzyme glucose isomerase. Although it is possible for HFCS to be contain up to 90% fructose, the most common product used contains around 42% fructose, as this most closely resembles sucrose. HFCS is less expensive and sweeter than white sucrose sugar, and so is a popular sweetener of beverages such as soda. In other instances, such as baking, many criteria determine what type of corn syrup, or sweetener will be used.
- Honey: A sweet syrup produced from the nectar of flowers by bees as a food source for the hive. Honey is always a mixture of glucose, fructose, a small amount of sucrose, and moisture, with some other sugars and impurities. Composition will vary depending on the flowers the bees used to produce the honey. A typical batch consists of around 40% fructose and 35% glucose, and 1 to 2% sucrose. Other sugars may include isomaltose, turanose, trehalose, erlose, maltotriose, melecitose, and raffinose, but these are present in only trace amounts of less than one percent. The rest is moisture, minerals, vitamins, beeswax, ash impurities in varying amounts, some enzymes, and aromatic volatile oils, which contribute to the unique flavor. The fructose in honey is sometimes referred to as levulose by the honey industry.
Since many recipes replace granulated sugar with more "healthy" honey, you may wonder what to substitute for the honey, should you only have white sugar or some other sweetener.
- Invert Sugar: A thin liquid solution of glucose and fructose produced by adding an acid3 to a solution of sucrose (sucrose dissolved in water). The acid hydrolyzes the sucrose, causing it to break down into d-glucose and d-fructose. Sweeter than white granulated sugar, it resists crystallization, making it ideal for professional candy makers who use it to give candy a smooth, melt-in-the-mouth, texture. Invert sugars are an important part of some candy making processes. See also Candy Making Sugar Stages.
- Lactose: Lactose is a natural disaccharide of glucose and galactose. It is the primary carbohydrate found in milk. Lactose is about 1/5 to 1/6 as sweet as sucrose, meaning it barely tastes sweet at all. It is highly prone to crystallization. The food industry uses lactose, separated from milk, as a browning agent in baked goods and to improve the water holding capacity of processed meats like ham. It is also used in the making of candies and frozen deserts (beside the natural lactose already found in the milk used to make ice cream, etc.). As an "added" sugar, it does not contribute much to the diet but as a natural sugar it is found abundantly.
- Maltose: Maltose occurs naturally whenever a starch molecule is broken down, whether by a plant to use it's stored starches as fuel, when seeds are germinating, or when starches are being digested in the intestinal tract. Maltose, is used in fermented beverages (beer), breakfast cereals, and some infant formulas.
The maltose used in making beer comes from malt or malt extract, which is a mix of broken down starches consisting mainly of maltose. Usually made from barley or wheat, cereal grains are allowed to sprout which causes the enzymatic breakdown (hydrolysis) of the starch to maltose.
Perhaps the most famous occurrence of maltose in a prepared food is Post's "Grape Nuts" cereal, which was made from wheat and malted barley. C.W. post is said to have mistaken the maltose for glucose (dextrose) which was commonly called "grape sugar" by manufactures at the time, hence the name Grape Nuts.
- Maple Sugar: Produced by boiling maple syrup until most of its water evaporates and the sugar crystallizes. This sugar, like maple syrup, is almost entirely sucrose with only small amounts of free glucose and fructose. It also naturally contains invert sugars. Maple sugar is not commonly used today.
- Molasses: Of all the "sugars" molasses can easily lay claim to being the most nutritious. Molasses is what is left over after the sucrose crystals are removed from the concentrated sugar cane (or beet) juice. It is boiled repeatedly in order to crystallize as much of the sugar as possible, until no more sucrose can be extracted. This repeated boiling makes the molasses become darker and darker. The darkness determines the grade, with Blackstrap molasses being the darkest and most bitter.
The amount of sucrose in molasses differs, depending on whether sugar cane or sugar beets was used. Sugar cane molasses contains about 30 to 40% sucrose, some glucose, fructose, and invert sugar. Sugar beet molasses contains about 60% sucrose. Other components are inorganic salts, organic acids including amino acids, hemicellulose and pectin fiber, waxes, and ash. You may find mollases products labelled unsulphured, so see Why Does my Mollases say Unsulphured? Was Sulphur Removed From it?.
- Raw Sugar: The term "raw sugar" as far as the consumer is concerned, should be considered a marketing joke, as there is no standard definition as to what kind of sugar can be called "raw." If you wanted to be particular, the word "raw" would mean that virtually no refining of the sugar had taken place. But this also begs the question of what is "sugar" and what is simply "dried cane juice". However, most experts would tend to consider raw sugar as sugar that is extracted from sugar cane juice but not refined any further. That is, not washed or decolored. True raw sugar contains dirt, insect parts, yeast, molds, and many other contaminants. As a result, the FDA banned its sale to the public.
However, there are some products sold as raw sugar to consumers, such as "Sugar in the Raw". These products labelled as raw sugar could be anything, but raw sugars typically are a cruder stage of the sugar production process, before "white sugar" is completely refined. In the United States, such sugar is called turbinado sugar after the centrifuge in which it is spun. In the U.K. it is called demerara sugar. This sugar has been centrifuged and some of the impurities removed but it retains a light brown, amber color due to the leftover molasses content. It is not truly "raw" however, it is simply partially refined, with larger crystal size. See Raw or Turbinado Sugar Versus White Sugar.
Image by Leena via Wikipedia
Sugar alcohols, which are also known as polyols are used in food labelled "sugar free" and are often referred to as nutritive sweeteners. Chemically, they are saccharide derivatives in which a ketone or aldehyde group has been replaced by a hydroxyl group. These are naturally present, in small amounts, in some fruits and vegetables but they are produced commercially by hydrogenating mono, di, or polysaccharides. They have become popular as a sugar alternative because they are sweet and possess similar properties but deliver less energy, about 1 to 2.5 less calories per gram, than sugar. They are absorbed more slowly and less completely by the intestines.
However, this incomplete and slow digestion leads to sugar alcohols being fermented by the intestinal flora. If consumed in excess, they can cause gastrointestinal upset in some people, leading to flatulence, diarrhea, bloating, and other symptoms.
The advantage, in terms of calorie reduction, would appear to be small. Also, there is the problem of the tendency for people to take in more energy from foods that appear to have less calories because of "sugar free" or other reduced macronutrient labeling. Sugar alcohols do have less of an impact on dental carries (cavities) however, because bacteria in the mouth metabolize them much more slowly. This makes them particularly suited to chewing gums, breath mints, or any product that remains in the mouth for long periods.
The sugar alcohols approved for use in the U.S. include erythritol, isomalt, lactitol, maltitol, mannitol, sorbitol, and polyglycitols (hydrogenated starch hydrolysates)4. These products are not intensely sweet like many artificial sweeteners, the non-nutritive sweeteners like saccharin, aspartame, and sucrolose, which are also called intense sweeteners. In fact, some of the sugar alcohols are only about half as sweet as sucrose, while others are about as sweet, but no sweeter.
Image by Glane23 via Wikimedia
Why Does Brown Sugar Become a Hard Lump?
When molasses is mixed back into white sugar, the molasses forms a film around the sugar crystals. As long as the molasses is moist, the brown sugar will be soft. But if the moisture is allowed to evaporate out of the molasses, it becomes something like a glue, causing all the sugar to stick together in a hard mass. To keep this from happening, brown sugar must be stored in an airtight container like a sealed plastic bag or tightly sealed glass jar. It may help to store it in the refrigerator.
A moist paper towel over the hard sugar will soften it back up, as the sugar draws the water in. This takes about 12 hours, however. You can also pop hardened brown sugar in the microwave for 10 to 15 seconds to soften it, but this is only temporary so the sugar must be used immediately. If your making chocolate chip cookies, make sure not to mix eggs into piping hot sugar!
What About Botulism in Honey?
The risk of botulism poisoning from honey consumption is a frequent concern. It is true that botulism spores (Clostridium botulism) may be present in honey. For this reason honey should never be given to children under the age of one year, as their intestines are not yet able to handle botulism spores, which may colonize the infant's intestines and produce botulism poisoning. In healthy older children and adults, there is little risk. See the link above for further explanation.
One survey in 1978, which examined honey from 32 U.S. states, estimated that the maximum amount of botulism contamination in honey was around 8 to 28 spores per kilogram of honey. Other surveys in different parts of the world found no contamination in some countries but contamination with different strains in others. The level of contamination worldwide, when randomly examined, tends to be very low, as little as 1 - 10 spores per kgs. Although honey should absolutely not be given to children under the age of one year, the levels of contamination associated with infant botulism are much, much higher, on the order of 104 spores per kilogram. These samples also tend to be limited to C. botulism, rather than A. or B. botulism, which may suggest that these high levels of contamination are not a random but normal incidence which is the result of contamination from and outside source or the the result of botulism amplification in the beehive for some reason.
What is Molasses Used For?
Sugar cane molasses is used to make rum. Rum can actually be made by distilling fermented sugar cane juice or molasses. Cane juice is preferred in the West Indies but most Rum is distilled from molasses, which is generally considered to be the best base. To make rum, a "mash" is started using molasses that has been diluted until it contains the desired concentration of sugar. This mash is then fermented by yeast. It is possible to simply allow the yeasts that are naturally present in the environment to ferment the sugar in vats that are open to the air but most distillers prefer at least some control, understandably so, over the specific type of yeast that is allowed to ferment their mash, short of absolute laboratory precision, which would undoubtedly take some of the art out of the production of Rum. So yeast is added to the mash and the conditions are controlled to allow those yeasts to ferment, producing ethanol alcohol and carbon dioxide as by-products.
If one were making beer, which used a "wort" instead of a mash, after fermenting is done, all that would be left would be to separate the liquid "beer" from the solid precipitates (including dead yeast), carbonate, either naturally by further fermentation in the bottle, or artificially (as large production beers must use), allow the beer to age, and then it is ready to drink. So in essence, the making of beers, like Ales or Lagers, and the making of liquors such a Rum or Whiskey, starts out much the same, although using different base ingredients to start.
However, Rum is a "distillate," which means that the alcohol within the fermented mixture is extracted and collected separately by distillation. To do this, the fermented liquid is heated in a sealed vessel to around 175 degrees Fahrenheit, which evaporates the alcohols from the liquid, which are run through pipes and allowed to recondense back into a liquid state to be collected. This is a "raw spirit," which contains between 70% to 95% alcohol. It can be sold as is, and is sold this way in certain places, such as the Carribean. But most Rum is first aged and then may be blended with spices or fruits. Afterwards, the distillery blends different batches of Rum together until the taste desired is achieved. If this step was skipped, every batch of Rum a certain distillery produced would taste different. Blending the Rums allows expert tasters to reproduce the same flavors in every batch of Rum that is put into bottles. Most rum is then diluted with water so that it contains 40 to 50% alcohol by volume. Molasses can also be used to produce ethanol alcohol for fuel.
Molasses is also used to produce baker's yeast (Saccaromyces cerevisiae), or feed yeast (a high protein feed supplement). The darker molasses grades, such as Blackstrap, is used in animal feeds for livestock (Blackstrap is also available for home use). It can also be used as a crop fertilizer, for which it has advantages and disadvantages.
Molasses is used widely in baking cookies, cakes, and breads and some people like to add molasses to sweet potato or pumpkin pie. It is also used sometimes used in toffees and caramels, and included in barbeque sauces and baked beans.
What's the Difference Between Molasses, Treacle, and Golden Syrup?
There seems to be a lot of debate about the difference between molasses, treacle and a product called "golden syrup." Apparently, this debate is not new but has been going on since the 1800's. Nobody today seems to really know the difference, but many claim there is one.
Today, treacle seems to be a generic word for any syrup made in the process of refining sugar cane. However, in older texts treacle is said to refer to the waste drained from the sugar molds after the sugar was removed from the molasses, or to a more clarified molasses product.
Treacle can range from light to dark but in common parlance treacle usually refers to the light syrup that results from the first boiling, which is also called light treacle or golden syrup. However, golden syrup sometimes refers to a treacle that has been further refined by reboiling and filtration through charcoal. There is also a version of this which was "invented" and sold by a Scotsman name Lyle Abam, a product which is still sold today. This has created some confusion about the origin of golden syrup.
Much darker syrups resulting from the second boiling, are called either just treacle or dark treacle by the British, which Americans call molasses. The product of a third boiling is called Blackstrap by the British and Americans alike.