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Download FST Ch 5 Carbohydrates
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CARBOHYDRATES Organic chemistry has given the name saccharide to all carbohydrates classified as sugars. Sugar was the common name used before organic chemists developed the system used today Sugars are organic compounds. That means they contain carbon compounds All living things are composed of carbonbased (organic) compounds Carbohydrates Are … one of the six essential nutrients The body’s main source of energy The sugars The starches The fibers in your diet Except for the natural sugar in milk, nearly all carbohydrates come from plant sources Carbohyddrates… …are made of three chemical elements Carbon Hydrogen Oxygen These are bonded together to form saccharides – sugar units How the elements are arranged, determines the type of sugar it is… Monosaccharide Disaccharide Polysacchride Monosaccharides Sugar in their simplest form Carbohydrate molecules that are building blocks for more complex carbohydrates Monosaccharides in Food Glucose – the most prevalent also called dextrose, grape sugar & corn sugar Found in fruits, vegetables, honey, corn syrup, and molasses FRUCTOSE The sweetest of all the sugars Found in honey, molasses, fruits & veggies Galactose Is produced when lactose(milk sugar) is digested Or when milk products are fermented (cheese& yogurt) SUGAR How Sweet It Is What is it? The white stuff we know as sugar is sucrose. It’s two simpler sugar stuck together frutcose & glucose Also called a…. DISACCHARIDES Contain 2 monosaccharides joined together Sucrose (table sugar) is the most common Glucose + fructose = sucrose Maltose – formed during the digestion of starch Also found in malted grains – the least sweet Lactose – sugar found in milk The body splits disaccharides into monosaccharides during digestion Called hydrolysis Lactase (enzyme) Glucose & galactose Galactose broken down to Glucose (in the liver) Glucose is used for energy Polysaccharides (Polymers) Poly = many Mer = parts Polymer = many parts They are long chains of molecules (it gets complicated!) Polysaccharide Examples Starch: is the storage form of energy in plants. Made of many glucose molecules bonded together. Breads, cereals, Corn, potatoes, & legumes (dried beans) Polysaccharide Examples Fiber: Make up the tough fibrous walls of plants. Not digested by humans Cellulose, gums, pectins Found in: Grain products – bread, cereal, corn, potatoes, & legumes COMPLEX Carbohydrates Man-Made Polymers Plastic, nylon, grease Natural Polymers Cotton, wool, hair, skin Protein, Gelatin Polysaccharides Sugar and its many disguises Honey, syrup, corn sugar, corn syrup, molasses, maple syrup, invert sugar, brown sugar, sucrose, fructose, glucose, dextrose, maltose, & lactose Anything that ends in “ose” Sugars 6 Functions in Food Prep Sweeteners Preservatives Tenderizers Crystallizing Agent Carmelizing Agent Fermenting Agent Sweetners Ability to sweeten is its major function in most foods. Scientists have found the sweeter the sugar is, the simpler the structure of the molecule is. The longer the sugar chain is, the less sweet the sugar will seem to be. Preservatives Sugar helps prevent food spoilage Water is drawn to sugar molecules before it is drawn to bacteria. Most single-celled contaminants will dehydrate and die in concentrated sugar solutions Helps products such as cakes stay moist Tenderizers Sugar interferes with the flour’s ability to form an elastic structure (Gluten) Compare the tenderness of An Italian hard roll A piece of white bread A sweet roll or donut Tenderizers The tenderizing effect of sugar changes the viscosity or “pourability” of a batter Crystallizing Agent Sugars ability to dissolve in water increases as the solution gets hotter. When water evaporates it increases the sugar concentration Sugar crystals that form on the side of the pan will trigger more crystallization. Put a lid on it. Steam will wash the crystals from the sides Interfering Agents A substance that can prevent or slow crystal growth. Corn syrup Butter Cream Caramelizing Agents When exposed to high heat – over a period of time it changes to brown liquid – caramel. It is partially responsible for the brown crust on baked goods and toast. And the distinctive taste and color of caramel candy SUGAR Solid at room temperature Liquifies when heated – changes from clear to yellow to brown/black – Called carmelization A chemical process Can be used in many ways Fermenting Agent Plays a major role in the fermentation of wine, beer and yeast breads. Sugar is the food supply for the microorganisms involved in the process. Promotes carbon dioxide production in yeast Acts a a dehydrating agent in pectin gel formation (jam & jellies) Lowers freezing point of mixtures (ice cream) Increases boiling point of mixture (candy) Part 1 The End Part 2 Simple Sugars And your Health Refined Sugars Sugars can be divided into 2 groups Sugar that occurs naturally in foods * milk & fruit Sugars added to foods during processing or at the table. Called REFINED SUGARS Refined Sugars Are… Sweeteners separated from their natural sources for use as food additives. Comes from sugar cane, sugar beets & corn Used as sweeteners, to increase bulk or aid browning Refined Sugars Sources… Soft drinks, candy, cake, cookies, donuts Also… many processed foods such as catsup, cereal, potato chips and… Reduced fat or fat free products Added sugar increases the calories in food without increasing the nutrients. (“empty calories”) In other words… Sugar Eat too much – have problems Obesity Diabetes, Bad teeth Experts recommend keeping sugar intake to no more than 25% of your total calories. For example: 2000 calorie diet = 500 calories from sugar. Health Related Questions Is Sugar Bad for your teeth? Yes! Too much sugar = tooth decay (dental caries) Bacteria feed on the carbohydrate particles & form plaque that clings to teeth. As bacteria grow they form acid that eats away tooth enamel, forming pits which can deepen into cavities. Sticky foods like cookies, crackers, caramels etc. cling to teeth. They are more harmful than foods that are quickly swallowed. Carbohydrates eaten at meals are less damaging than between meal snacks because they are removed by beverages and other foods eaten with them. Do not allow a baby to sleep with a bottle in their mouth. The acids formed can destroy their teeth After feeding, clean gums and teeth with a soft, clean cloth Does sugar cause hyperactivity? Researchers have found no proof… However… Children who eat large amounts of sweets may be missing important nutrients. Eating a more nutritious diet can improve performance. Is sugar addictive? People are born with a preference for sweet- tasting foods. Researchers think that the need for sugar is psychological. We eat sweets because we like them – not because we are addicted to them. Does Too Much Sugar Cause Diabetes? Diabetes mellitus – and inability to use the hormone insulin. Insulin regulates blood glucose level by pulling glucose from the bloodstream. When the body does not make enough or does not use it correctly, glucose builds up in the bloodstream. Two Types of Diabetes Type I – insulin-dependent Pancreas does not make insulin Occurs mostly in children & young adults Must take injections to regulate Type II or noninsulin –dependent Body does not respond well to the insulin that the pancreas makes Usually occurs in adults over 40 People who are overweight People whose diets are high in refined sugar and low in fiber Can often be controlled with diet and physical activity Hypoglycemia (low blood sugar) Body produces too much insulin and causes blood sugar to drop sharply 2-4 hours after eating Avoid eating large amounts of sugar at one time. Eat at regular intervals Lactose Intolerance The inability to digest lactose – the carbohydrate enzyme in milk. Symptoms: gas, cramping, nausea & diarrhea Occurs most often among nonwhite populations Develops as people age May be able to eat milk products such as yogurt, cheese & buttermilk since the lactose is broken down during the culturing process. Will have to get calcium from other sources. So… Exactly what carbohydrates should I eat? Complex Carbohydrates Dividing carbohydrates into simple & complex makes sense on a chemical level But doesn’t explain what happens to different carbs inside the body. Starch in white bread & French fries qualifies as “Complex” – yet the body converts this starch to blood sugar almost as fast as it processes pure glucose Fructose is a simple carb, but has minimal effect on the blood sugar Other factors that influence how quickly the carbohydrates raise blood sugar include How much it has been processed Fiber content Ripeness – more ripe=more sugar Fat & acid content. Physical form – finely ground vs. coarsely ground For optimal health get your grains intact from Whole wheat bread Brown rice Whole grain pasta Old-fashioned rolled oats Beans (pinto, black, kidney, garbanzo etc) Fresh fruit Fresh vegetables Take good care of yourself You are the only “You” that you’ve got!!