Carbohydrates Carbohydrates

What are Carbohydrates  An organic compound that is the body’s main source of energy.  They are found mainly in plants  There are two groups of carbohydrate – simple and complex

Simple Carbohydrates  Sugar makes up simple carbohydrates - it is another word for saccharides.  Monosaccharides – single sugars which are the building block of other sugars.  Glucose is a simple sugar often which builds all carbohydrates  - Fructose is a simple sugar found in fruits  Galactose is not found free in nature but is always bound to something else

 Disaccharides – sugars made up of two monosacchrides bonded together.  Sucrose – a common monosacchride made up of glucose and fructose.  Lactose – is found in milk made up of glucose and galactose.  Maltose – found in cereals and sprouting grains made up of two molecules of glucose.

Properties of Sugar  Sweetness- some are sweeter than others : fructose, sucrose, glucose, galactose, maltose, and lactose. fructose, sucrose, glucose, galactose, maltose, and lactose. Caramelization – the browning reaction that can occur with any kind of sugar Solubility – Sugars are very soluble or dissolvable in water. The sweeter the sugar, the more it can dissolve in water.

 Crystallization – crystals form when you add more sugar to a solvent than it can dissolve. As you raise the temperature water evaporates increasing the concentration of sugars. When sugar reaches a certain concentration, crystalization occurs. The sugar crystals separate from the solution, each sugar in an organized pattern of molecules.

Complex Carbohydrates Starch and Fiber  Starch is made up of chains of sugar molecules called polysaccharides.  Examples of Complex Carbs = dry beans, peas, lentils, potatoes, corn, rice, pasta, and breads

Fiber  Fiber is what gives plants their structure.  Bran – the most concentrated form of fiber forms the outer layer of grains.  Fiber also is useful by carrying excess cholesterol out of the body.  A n important function of fiber is to move food through the digestive tract.

Carbohydrates in the Body  Carbohydrates provide fuel for the body  Glucose is called blood sugar  Hydrolysis of Sugars – in the small intestine compounds are split into smaller parts by the addition of water. This releases glucose to be used for energy. Example: Sucrose + Water = Glucose + Fructose  Enzymes with water act on the sugar to break it down.

Blood Glucose Levels  The pancreas monitors the flow of glucose to the cells.  The pancreas secretes insulin- a messenger that signals the cells to accept the surge of nutrients including glucose.

 If blood glucose is too high, insulin tells the liver and muscles cells to remove glucose from the blood and store it as glycogen.  If blood glucose is too low, glycogen is released from the liver and changed into glucose and released into the blood.

Diabetes  A condition where the body can not regulate blood glucose levels.  Type I = the pancreas secretes little or no insulin. ( Common among child diabetes)  Type II = insulin is produced but not enough or can not be used effectively. (Most common)  Both types can cause high blood glucose levels which strains and damages the heart and kidneys

Diabetes  Type I diabetes where no insulin is produced, cells cannot use the energy in food. A diabetic coma may result.  Type II diabetes cells get enough glucose to avoid tapping into fats and proteins. A person often becomes obese trying to feed glucose hungry cells. This causes the cells to be less sensitive to insulin.

Sweeteners  Sucrose extracted from sugar beets or sugar cane is our white granulated sugar.  Brown sugar is granulated sugar flavored with molasses.

Sugar Substitutes  Sucralose is an artificial sweetener that is a chlorinated sucrose derivative. Because the body cannot recognize the chlorinated carbohydrate, it is not absorbed by the body so does not add calories to you. It does not break down when heated so is good for baking.  Aspartame – is an amino acid-based sweetener often used in diet pop. It does not promote tooth decay nor does it have an aftertaste.

Starches as Thickening Agents Starches as Thickening Agents Starches are used in food preparation as thickening agents. When a starch is heated in water, energy from the water molecules loosen the bonds between the starch molecules. Hydrogen bonds form between starch and water molecules, causing starch granules to absorb water and SWELL.

Syneresis of a Starch  Syneresis -is where water leaks from the gel as it ages, collecting on top of the gel. The mixture has the appearance of “weeping” because drops of moisture sit on top of it.

Modifying Starches Food Scientists rework the molecular structure or genetic makeup of an existing starch resulting in a starch that is more stable after heating or freezing. Modifying starches is how food scientists developed instant pudding. They designed a starch that would swell in cold liquids.