Finish everyday and be done with it. You have done what you could; some blunders and absurdities no doubt crept in; forget them as soon as you can. Tomorrow is a new day; you shal begin it serenely and with too high a spirit to be encumbered with your old nonsense.
Ralph Waldo Emerson
The Dark Side of Fast Food: Why Does It Make You Sick / Fat / Tired / Taste So Good
What Are Simple and Complex Carbohydrates?
Carbohydrates are divided into two categories based on the number of units that are joined together. Simple carbohydrates include monosaccharides (mono = one, saccharide = sugar) and disaccharides (di = two), and complex carbohydrates include polysaccharides (poly = many).
Simple Carbohydrates Contain One or Two Sugar Units
Three monosaccharides are found in foods. In addition to glucose, which we just discussed, there are fructose and galactose. Fructose is the sweetest of the simple sugars and is found abundantly in fruit. For this reason, it is often referred to as fruit sugar. Galactose is found in dairy foods. From these three sugars, the disaccharides can be created:
When glucose and fructose join together, the disaccharide sucrose, or table sugar, is formed.
When two glucose units join together, the disaccharide maltose is created. Maltose is the sugar found in grains, such as barley. It is used in the process of brewing beer.
When glucose and galactose join together, the disaccharide lactose is created. Lactose is often called milk sugar, as it is found in dairy foods.
Polysaccharides Are Complex Carbohydrates
Polysaccharides consist of long chains of monosaccharides linked together.These chains contain many combined glucose units, which is why they are called complex carbohydrates. Starch, fiber, and glycogen are the three groups of polysaccharides.
Starch Is the Storage Form in Plants
Plants can store thousands of straight or branched glucose units strung together as starch. The straight chains of glucose units in starch are called amylose, whereas branched chains are called amylopectin. The many branches in amylopectin enable the body to break it down quickly and easily compared with amylose because there are so many sites where the enzymes can attach. Starchy foods with highly branched amylopectin, such as potatoes, rice, bread, pasta, and cereals, are digested more rapidly than foods rich in amylose, such as legumes (dried peas, beans, and lentils).
Fiber Is Non digestible but Important
Humans lack the digestive enzyme needed to break down fiber, so for the most part, fiber is the part of the plant that we eat but cannot digest. Plant components like cellulose, hemicellulose, lignins, gums, and pectin are all types of fibers. Dietary fiber is found naturally in foods and functional fiber is added to food for a specific, beneficial effect. For example, psyllium is a functional fiber derived from wheat husks. It can be added to breakfast cereals to help promote regular bowel moments. Together, dietary and functional fibers account for the total fiber that you eat. Many compounds can be classified as both dietary fiber and functional fiber, depending on how they are used. Pectin occurs naturally in foods such as apples and citrus fruits and would be considered a source of dietary fiber. However, pectin can also be isolated and added to foods, such as nonfat yogurt, to add texture. In this situation, pectin is considered a functional fiber.
Fiber is sometimes also classified by its properties when combined with water. Soluble fiber dissolves in water, whereas insoluble fiber does not. Soluble fiber can be viscous (though not all soluble fibers are viscous); that is, it can have gummy or thickening properties. For example, the viscous soluble fiber in oats and beans thickens cooked oatmeal and bean chili. When you eat such foods, their soluble fiber is fermented (or digested) by bacteria in your large intestine. In contrast, insoluble fiber, found in foods such as bran flakes, is not viscous and is fermented less readily by bacteria.
A fiber’s solubility affects how quickly it moves through the digestive tract. This classification system isn’t exact, as most foods typically contain both types of fiber and some fibers can have multiple effects in your body. In general, insoluble fibers include cellulose, hemicellulose, and lignins and are found in the bran portion of whole grains, cereal fiber, seeds, and in many fruits and vegetables. They typically move more quickly through your intestinal tract, so can have a laxative effect. Soluble fiber-like pectin in fruits and vegetables, beta-glucan in oats and barley, gums in legumes, and psyllium-is more viscous and moves slowly through your digestive system. Meat and dairy products do not contain fiber. Even though fiber is mostly nondigestible, it can have powerful health effects.
Glycogen Is the Storage Form in Animals
Glycogen is the storage form of glucose in humans and animals and is found in the liver and in muscle cells. Glycogen is branched glucose similar to amylopectin. Humans store only limited amounts of glycogen in their bodies, but it can be an important source of glucose for the blood. People can’t access the carbohydrates stored in meats and poultry because the glycogen stored in animals breaks down when the animals die.
Creating Monosaccharides, Disaccharides, and Polysaccharides
(a) Fructose, glucose, and galactose are the three monosaccharides that are found in nature.
(b) The disaccharides sucrose, maltose, and lactose are created from the monosaccharides.
(c) The polysaccharide, starch, is composed of many glucose units joined together.
Unripe fruit tastes more starchy than sweet. As fruit ripens, its complex carbohydrates are broken down into simple sugars, including fructose. The more it ripens, the more fructose it has.
Most Plant Foods Contain both Soluble and Insoluble Fibers
The skin of an apple is high in cellulose, an insoluble fiber, while the pulp is high in pectin, a soluble fiber.
Terms:
Glycogen – The storage form of glucose in humans and animals.
Fiber – A nondigestible polysaccharide.
Starch – The storage form of glucose in plants.
Lactose – A disaccharide composed of glucose and galactose; also known as milk sugar.
Maltose – A disaccharide composed of two glucose units joined together.
Sucrose – A disaccharide composed of glucose and fructose. Also known as table sugar.
Galactose – A monosaccharide that links with glucose to create the sugar found in dairy foods.
Fructose – The sweetest of the monosaccharide’s; also known as fruit sugar.
Polysaccharide – Many sugar units combined. Starch, glycogen, and fiber are all polysaccharides.
Complex carbohydrates – A category of carbohydrates that contain many sugar units combined. A polysaccharide is a complex carbohydrate.
Disaccharide – Two sugar units combined. There are three disaccharides: sucrose, lactose, and maltose.
Monosaccharide – One sugar unit. There are three monosaccharides: glucose, fructose, and galactose.
Simple carbohydrates – A category of carbohydrates that contain a single sugar unit or two sugar units combined. Monosaccharides and disaccharides are simple carbohydrates. functional fiber The nondigestible polysaccharides that are added to foods because of a specific desired effect on health.
Dietary fiber – Nondigestible polysaccharides found in foods.
Insoluble fiber – A type of fiber that doesn’t dissolve in water and is not fermented by intestinal bacteria.
Soluble fiber – A type of fiber that dissolves in water and is fermented by intestinal bacteria. Many soluble fibers are viscous and have gummy or thickening properties.
