Download - CHAPTER 5 CARBOHYDRATES. LEARNING OUTCOMES Identify the major types of carbohydrates and give examples of food sources for each List alternative sweeteners.

CHAPTER 5

CARBOHYDRATES

LEARNING OUTCOMES

• Identify the major types of carbohydrates and give examples of food sources for each• List alternative sweeteners that can be used to

reduce sugar intake and know how they work• Describe recommendations for carbohydrate

intake and health risks caused by low or excessive intakes• List the functions of carbohydrates in the body

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LEARNING OUTCOMES

• Explain how carbohydrates are digested and absorbed• Identify the cause of, effects of and dietary

treatment for lactose intolerance• Describe the regulation of blood glucose,

conditions caused by blood glucose imbalance, types of diabetes, and dietary treatment for diabetes• Explain the basis of low carbohydrate diets and

low glycemic index diets and the pros and cons of following them

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CARBOHYDRATES

• Composed of carbon, hydrogen and oxygen• Produced by plants via

photosynthesis• Simple carbohydrates• Monosaccharides and

Disaccharides

• Complex carbohydrates• Polysaccharides,

Glycogen and Fiber

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CARBOHYDRATES

Sources of carbohydrates in the diet: PlantsPlants use carbon and oxygen from the CO2 in the air and hydrogen from H2O and energy from the sun to make glucose (carbs).•Pasta•Rice•Potatoes•Bread•Fruits•Veggies•Milk•Legumes

These foods should make up 45-65% of our daily intakeDesserts

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MONOSACCHARIDES

6 carbon, single units•Glucose• Blood sugar, corn syrup

• Fructose• Fruit sugar

•Galactose• Part of lactose

•Sugar Alcohols• Xylitol, mannitol and sorbitol

•Pentoses (5 carbon)• Ribose and Deoxyribose

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MONOSACCHARIDES (SIMPLE SUGAR)

Each contains 6 Carbons12 Hydrogen6 Oxygen atomsbut in different configurations

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DISACCHARIDES (SIMPLE SUGAR)

Two monosaccharides linked by a condensation reaction (loss of H20 molecule in this case.)

•Maltose• Glucose and Glucose-alpha

bond•Sucrose • Glucose and Fructose-alpha

bond•Lactose• Galactose and Glucose-

beta bond

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DISACCHARIDES

SucroseAlpha bond

MaltoseAlpha bond

LactoseBeta bond (harder to break down)

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OLIGOSACCHARIDES

• Oligo (means “few” and is 3-10 in this case)• Raffinose- • Stachyose (found in some vegetables, grains

and beans)

• Our bodies cannot break down oligosaccharides they get to our small intestines where the bacteria there metabolize them and turn them into gas.• Beano can break down these sugars for us

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DIGESTIBLE POLYSACCHARIDES

Polysaccharides• Contains many glucose molecules (hundreds to

thousands)• Alpha or beta bond determine digestibility

Starch • Amylose-straight chain• Amylopectin-branched

Glycogen- digestible• Storage form of glucose in human body

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Amylose (1-4 alpha bonds broken by amalase)

Amylopectin (1-4 and 1-6 alpha bonds- broken by alpha-dextrinase)

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Glycogen (alpha bonds) - Storage form of carbohydrates in animals

•The liver can store about 90 grams of CHO (360 kcals)•The muscles can store about 300 grams of CHO (about 1200kcal)

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INDIGESTIBLE POLYSACCHARIDES

Fiber

•These carb bonds are not digested by humans so they pass through the SI to the LI where they are metabolized by our gut bacteria and produce S-CFA and gas. •S-CFA provide kcals for gut flora

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TOTAL FIBER = DIETARY FIBER (SOLUBLE + INSOLUBLE) + FUNCTIONAL FIBER

Dietary Fiber (beta bonds)Soluble Fiber• Dissolves in water• Forms gel and can slow down

digestion- good for regulating blood glucose, weight, and can interfere with cholesterol reabsorption.

• Used commercially to thicken foods

• Found in oat bran, fruits, beans

• Pectins• Some hemicellulose• Gums and mucilages

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TOTAL FIBER = DIETARY FIBER (SOLUBLE + INSOLUBLE) + FUNCTIONAL FIBER

Dietary Fiber (beta bonds)

Insoluble Fiber•Good for treating constipation •Adds bulk to stool and increases transit time in large intestine•Found in whole grains

• Cellulose• Hemicellulose• Lignins

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DIETARY FIBER

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• Functional fiber also called “isolated” fibers. These are “faux” fibers added to foods for potential health

benefits and clever marketing. • Just like dietary fiber, these fiber additives pass undigested

through the gastrointestinal tract, so the FDA accepts them as the real deal.

• Yet no scientific studies link these artificial fibers to the health benefits—including a lowered risk of heart disease and obesity

Can’t turn junk food into a health food

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The most common isolated fibers manufacturers use to bulk up not-so-fibrous foods include:•Maltodextrin•Inulin (chicory root)•Polydextrose•Oat fiber•Resistant starch•Pectin•Gum

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WHOLE GRAINS

Whole grains, or foods made with whole grains contain all the essential (an naturally occurring) parts of the entire grain seed. •Amaranth•Barley•Buckwheat•Corn•Millet•Oats•Quinoa•Rice (brown)•Rye•Sorghum•Teff•Triticale•Wheat

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WHOLE GRAINS

Since whole grains lose so many nutrients, food manufacturer must add back iron and the B vitamins riboflavin, niacin thiamine (1973), and folic acid (1998) this called enriched flour.

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1997

WHOLE GRAINS

16 grams of whole grains = 1 serving•Recommend 3 servings or 48 grams daily•Which cereals are whole grain? (a)Total(b)Special K(c)corn flakes(d)shredded wheat(e)cream of wheat

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IS THIS A GOOD SOURCE OF WHOLE GRAINS?

16 crackers - 2 gram fiber- 23 grams CHO150 kcal

Ingredients: WHOLE GRAIN WHEAT FLOUR, UNBLEACHED ENRICHED FLOUR (WHEAT FLOUR, NIACIN, REDUCED IRON, THIAMINE MONONITRATE {VITAMIN B1}, RIBOFLAVIN {VITAMIN B2}, FOLIC ACID), SOYBEAN OIL, SUGAR, CORNSTARCH, MALT SYRUP (FROM BARLEY AND CORN), INVERT SUGAR, SALT, VEGETABLE COLOR (ANNATTO EXTRACT, TURMERIC OLEORESIN). BHT ADDED TO PACKAGING MATERIAL TO PRESERVE FRESHNESS.

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2 slices of bread- 4 gram fiber- 25 grams CHO130 kcalEnriched Wheat Flour [Flour, Barley Malt, Ferrous Sulfate (Iron), B Vitamins (Niacin, Thiamine Mononitrate (B1), Riboflavin (B2), Folic Acid)], Water, Whole Wheat Hour, High Fructose Corn Syrup or Sugar, Yeast, Wheat Gluten, Brown Rice Flour, Soy Fiber, Calcium Sulfate, Contains 2% or Less or Soybean Oil, Salt, Vinegar, Cornstarch, Wheat Starch, Soy Flour, Honey, Dough Conditioners (Sodium Stearoyl Lactylate, DATEM, Mono and Diglycerides, Ethoxylated Mono and Diglycerides, Dicalcium Phosphate, Calcium Dioxide and/or Azodicarbonamide), Yeast Nutrients (Ammonium Sulfate, Ammonium Chloride, Monocalcium Phosphate and/or Ammonium Phosphate), Enrichment [Vitamin E Acetate, Ferrous Sulfate (Iron), Zinc Oxide, Calcium Sulfate, Niacin, Vitamin D, Pyridoxine Hydrochloride (B6), Folic Acid, Thiamine Mononitrate (B1) and Vitamin B-12], Calcium Propionate (to Retain Freshness), Whey, Soy Lecithin.

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1 English muffin- 3 gram fiber- 23 grams CHO 120 kcalWhole Wheat Flour, Water, Yeast, Wheat Gluten, Honey, Farina, Cornmeal, Salt, Cracked Wheat, Preservatives (Calcium Propionate, Sorbic Acid), Grain Vinegar, Calcium Sulfate, Soybean Oil, Wheat Starch, Mono- and Diglycerides, Datem, Natural Flavor, Sodium Stearoyl Lactylate, Ethoxylated Mono- and Diglycerides, Wheat Sour, Dextrose, Calcium Carbonate, Guar Gum, Lactic Acid, Molasses, Fumaric Acid, Whey, Soy Flour (Trivial Amount of Soy Flour), Caramel Color, Acetic Acid, Sucralose, Citric Acid, Sodium Citrate, Natamycin (a Natural Mold Inhibitor), Potassium Sorbate (Preservative), Nonfat Milk.

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2 waffles- 3 gram fiber- 21 grams CHO 140 kcalIngredients: Water, Enriched Flour (Wheat Flour, Niacin, Reduced Iron, Thiamin Mononitrate [Vitamin B1], Riboflavin [Vitamin B2], Folic Acid), Whole Wheat Flour, Wheat Bran, Egg Whites, Sugar, Vegetable Oil (Soybean Oil, Palm Oil and Palm Kernel Oil with TBHQ and Citric Acid for Freshness), Contains Two Percent or Less of Leavening (Baking Soda, Sodium Aluminum Phosphate, Monocalcium Phosphate), Salt, Nonfat Dry Milk, Natural Flavors, Calcium Carbonate, Polyglycerol Esters of Fatty Acids, Malt Flavoring, Modified Cornstarch, Whey, Soy Lecithin, Vitamin A Palmitate, Guar Gum, Niacinamide, Reduced Iron, Thiamin Hydrochloride (Vitamin B1), Pyridoxine Hydrochloride (Vitamin B6), Riboflavin (Vitamin B2), Calcium Pantothenate, Folic Acid, Vitamin B12.

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SWEET

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HIGH FRUCTOSE CORN SYRUP?

• Starts out as cornstarch, which is enzymatically degraded to glucose and some short polymers of glucose and then again into fructose- now similar to sucrose

• Some believe that your body reacts differently to high-fructose corn syrup than it does to other types of sugar

• According to commercials “High-fructose corn syrup is made from corn, has no artificial ingredients, has the same calories as sugar and is okay to eat in moderation.”

• Can extend the shelf-life of foods• Subsidized commodity = In almost everything

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HIGH FRUCTOSE CORN SYRUP?

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HFCS

SUGAR ALCOHOLS

• Add energy (about 1.5- 3kcal/g) sorbitol, mannitol, xylitol• Caries• Sugar alcohols are usually incompletely absorbed into the blood

stream from the small intestine which generally results in a smaller change in blood glucose than "regular" sugar (sucrose).

• Popular sweeteners among diabetics and people on low-carbohydrate diets.

• Like many other incompletely digestible substances, overconsumption of sugar alcohols can lead to bloating, diarrhea and flatulence because they are not absorbed in the small intestine

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NON-NUTRITIVE SWEETENERS (ALTERNATIVE, ARTIFICIAL)

Yield no energy so are used to provide sweetness to a lot of products

•Saccharin•Cyclamate•Aspartame•Neotame•Sucralose•Acesulfame-K•Tagatose•Stevia

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ALTERNATIVE SWEETENERS

Saccharin•Oldest alternative sweetener•Cannot be used in cooking•300 times sweeter than sugar•Used to be thought to cause cancer in large amounts (bladder cancer in rats)•ADI (Acceptible daily intake: 5mg/kg (154#, 70 kg person this is three, 12 ounce cans of soda, or 9 packets)•Some fountain beverages

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Aspartame (Equal)•In diet sods•Contains phenyalanine (PKU)•Cannot be used in cooking, •Very sweet (180-200 times sweeter than sucrose) so only small amountsneeded (does provide 4kcal/g)•ADI for adult is 50mg/kg (18 cans of soda or 80 packets)

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ACE-K•Sunette•200 times sweeter than sucrose•0kcal/kg•Can be used in baking

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Sucralose (Splenda)•600 times sweeter than sucrose• Made from sucrose-can be used in cooking• Substitutes Chlorine for hydroxyl groups• Body cannot use it for energy• Can be used for cooking• Passed all safety tests• Splenda same ADI as sacharrin 3 x 12 oz diet

sodas or 7 packets/day

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Stevia• From a shrub in S. America, 100-300x sweeter

than sugar• Herbal supplement- only specific highly refined

and purified extracts of stevia have been approved for use in food products.• Concern it may cause infertility• ADI is 4mg/kg

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NON-NUTRITIVE SWEETENERS (ALTERNATIVE, ARTIFICIAL)

Are they safe?•Determined by the FDA•ADI are set at 100 x less than the level at which no harmful effects were seen in animals•Personal preference especially during pregnancy

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Non-nutritive sweeteners Are they safe?

Saccharin• Many studies on animals have shown that saccharin can

cause cancer of the urinary bladder. • In other rodent studies, saccharin has caused cancer of

the uterus, ovaries, skin, blood vessels, and other organs.

• Other studies have shown that saccharin increases the potency of other cancer-causing chemicals. And the best epidemiology study (done by the National Cancer Institute) found that the use of artificial sweeteners (saccharin and cyclamate) was associated with a higher incidence of bladder cancer.

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NON-NUTRITIVE SWEETENERS ARE THEY SAFE?

Aspartame (Equal, NutraSweet)•Might cause cancer or neurological problems such as dizziness or hallucinations.•A 1970s study suggested that aspartame caused brain tumors in rats. However, the Food and Drug Administration persuaded an independent review panel to reverse its conclusion that aspartame was unsafe.

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• The California Environmental Protection Agency and others have urged that independent scientists conduct new animal studies to resolve the cancer question.

• In 2005, researchers at the Ramazzini Foundation in Bologna, Italy, conducted the first such study. It indicated that rats first exposed to aspartame at eight weeks of age caused lymphomas and leukemias in females. However, the European Food Safety Authority reviewed the study and concluded that the tumors probably occurred just by chance.

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In 2007, the same Italian researchers published a follow-up study that began exposing rats to aspartame in utero. This study found that aspartame caused leukemias/lymphomas and mammary (breast) cancer. It is likely that the new studies found problems that earlier company-sponsored studies did not because the Italian researchers monitored the rats for three years instead of two. The Italian tests remain controversial, with the industry contending that they were flawed in several ways and with the FDA stating its scientists couldn't evaluate the studies because the researchers refused to provide their original data.

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