Carbohydrates

1
Carbohydrates

• Chapter 5

2
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

3
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

4
Carbohydrates

• Composed of carbon, hydrogen and oxygen
• Produced by plants via photosynthesis
• Simple carbohydrates
• Monosaccharides and Disaccharides
• Complex carbohydrates
• Polysaccharides, Glycogen and Fiber

5
Carbohydrates

• Sources of carbohydrates in the diet Plants
• Plants 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
  intake
• Desserts

6
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

7
Monosaccharides (simple Sugar)

• Each contains
• 6 Carbons
• 12 Hydrogen
• 6 Oxygen atoms
• but in different configurations

8
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

9
Disaccharides

• Sucrose
• Alpha bond
• Maltose
• Alpha bond
• Lactose
• Beta bond (harder to break down)

10
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

11
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

12
Digestible Polysaccharides

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

13
Digestible Polysaccharides

• 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)

14
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

15
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

16
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

17
Dietary Fiber
18
Indigestible Polysaccharides

• 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 benefitsincluding a lowered
  risk of heart disease and obesity
• Cant turn junk food into a health food

19
Indigestible Polysaccharides

• 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

20
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

21
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.

1997
22
Whole Grains

• 16 grams of whole grains 1 serving
• Recommend 3 servings or 48 grams daily
• Which cereals are whole grain?
• Total
• Special K
• corn flakes
• shredded wheat
• cream of wheat

23
Is this a good source of whole grains?

• 16 crackers - 2 gram fiber- 23 grams CHO
• 150 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.

24
Is this a good source of whole grains?

• 2 slices of bread- 4 gram fiber- 25 grams CHO
• 130 kcal
• Enriched 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.

25
Is this a good source of whole grains?

• 1 English muffin- 3 gram fiber- 23 grams CHO 120
  kcal
• Whole 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.

26
Is this a good source of whole grains?

• 2 waffles- 3 gram fiber- 21 grams CHO 140 kcal
• Ingredients 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.

27
Sweet
28
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

29
High fructose corn syrup?
HFCS
30
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

31
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

32
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

33
Alternative Sweeteners

• 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)

34
Alternative Sweeteners

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

35
Alternative Sweeteners

• 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

36
Alternative Sweeteners

• 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

37
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

38
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.

39
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.

40
Non-nutritive sweeteners Are they safe?

• 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.

41
Non-nutritive sweeteners Are they safe?

• 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.