FATS

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FATS

• The good and the bad
• Lecture 5
• February 7, 2008
• Dr. Quadro

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Six Classes of Nutrients

• Carbohydrate
• Protein
• Fat
• Vitamins
• Minerals
• Water

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• Satiety the feeling of fullness or satisfaction
  that people feel after meals.
• Fats slow the rate at which the stomach empties.

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Fat in cells

• After eating, the body stores some fat as an
  energy reserve.
• The body has unlimited potential to store fat.
• Excess carbohydrate and protein can be converted
  to fat, but they cannot be made from fat.
• One pound of body fat is worth 3,500 calories.

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Adipocytes Fat Cells

• Store triglycerides
• Distribution - to some extent sex-dependent
• Female Male
• ? lower body ? intra-abdominal
• ? back side and thighs ? around waist and
  shoulders
• ? around mammary glands
• The fatty acid composition dependent on the fat
  composition of the average food intake
• Can test adipocytes to get accurate impression of
  average dietary fat intake of the last six months

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• Lipids a family of compounds that includes
• Triglycerides (fats and oils)
• Phospholipids (lecithin)
• Sterols (cholesterol)
• Obvious sources of fat are oil, butter, margarine
  and shortening.
• Other foods contributing fat include meat, nuts,
  mayonnaise, salad dressings, eggs, bacon, gravy,
  cheese, ice cream and whole milk.

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Fat Structure - Triglycerides
H
C
OH
H
OH
C
H
C
OH
H
H
Glycerol
Diglyceride
Monoglyceride
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Fatty Acids

• A class of compounds with a long hydrocarbon
  chain and a terminal carboxyl group

Terminal Carboxyl
Terminal Carboxyl
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Naming Fatty Acids

• Length of chain ( carbons usually even)
• 16 and 18 are most common
• Number of double bonds
• degree of saturation (monounsaturates,
  polyunsaturates)
• the exact position of these double bonds
• Configuration isomerization
• Cis
• Trans

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• Saturated fatty acid a fatty acid carrying the
  maximum possible number of hydrogen atoms (having
  no points of unsaturation). Saturated fats are
  found in animal foods like meat, poultry, and
  full-fat dairy products, and in tropical oils
  such as palm and coconut.

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• Unsaturated fatty acid a fatty acid with one or
  more points of unsaturation. Unsaturated fats are
  found in foods from both plant and animal
  sources. Unsaturated fatty acids are further
  divided into monounsaturated fatty acids and
  polyunsaturated fatty acids.

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The Types of Fatty Acids

• Monounsaturated fatty acid a fatty acid
  containing one point of unsaturation, found
  mostly in vegetable oils such as olive, canola,
  and peanut.
• Polyunsaturated fatty acid (sometimes
  abbreviated PUFA) a fatty acid in which two or
  more points of unsaturation occur, found in nuts
  and vegetable oils such as safflower, sunflower,
  and soybean, and in fatty fish.

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Naming Fatty Acids

• Length of chain ( carbons usually even)
• Number of double bonds

Docosahexaenoic acid
226 w-3
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Further classification of the PUFA
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Essential Fatty Acids

• Must be supplied by the diet
• we need them and cannot make them
• Linoleic Acid 182
• Linolenic Acid 183

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Essential - omega fatty acids

• Omega-3 fatty acids, found in fish oils, offer a
  protective effect on health.

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Omega 3 (w-3) Fatty Acids

• Eicosapentanoic acid (EPA) 205
• Docosahexaenoic acid (DHA) 226

http//lansbury.bwh.harvard.edu/polyunsaturated_fa
tty_acids.htm
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Sources of Omega 3s

• Animal Sources Fatty fish and fish oil
• Grams/3.5 oz. Serving
• SARDINES, NORWAY 5.1
• SALMON, CHINOOK 3.0
• PINK SALMON 1.9
• ALBACORE TUNA 1.7
• RAINBOW TROUT (U.S) 1.1
• Plant sources
• Flaxseed
• Canola oil
• Walnuts (3.8g in 1.5oz.)

The National Academy of Sciences recommends
a daily intake of 1.6g (men) and 1.1 (women)
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Omega 3 Labeling - Qualified Health Claim

• Supportive but not conclusive research shows that
  consumption of EPA and DHA omega-3 fatty acids
  may reduce the risk of coronary heart disease.
  One serving of name of food provides X grams
  of EPA and DHA omega-3 fatty acids. See
  nutrition information for total fat, saturated
  fat and cholesterol content.

For Foods Sept. 2004
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Structure Function Claim w-3

• No minimum level of omega-3 fatty acids required
• Foods do not have to meet any specific criteria
• Examples of some structure/function claims
• Omega-3s support cardiovascular health
• Omega-3s support healthy brain function
• Omega-3s support healthy brain and eye
  development
• Omega-3s support a healthy immune system
• Omega-3s are beneficial for health maintenance
• In using a structure/function claim the
  manufacturer is responsible for ensuring the
  accuracy and truthfulness of the claims the FDA
  does not pre-approve the claims, however, they
  must be truthful and not misleading

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Omega 3 Products
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Omega 3 Ingredients BusinessFood and
Supplements

• According to Frost Sullivan, the US omega-3 and
  omega-6 poly-unsaturated fatty acid (PUFA)
  ingredients market is valued at 204.5 million
• The market is forecast to grow to 524 million by
  2011 at a compound annual growth rate of 14.4 per
  cent
• Marine oils comprise more than 65 of the total
  market in terms of revenues
• According to Ocean Nutrition, the US fish oil
  supplements ingredients market is worth more than
  300 million and is growing at up to 25 per cent
  a year

http//www.ffnmag.com/NH/ASP/strArticleID/778/strS
ite/FFNSite/articleDisplay.asp
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Triglyceride
95 of the lipids in foods and our body
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Triglycerides

• OIL Liquid a Room Temperature
• FAT Solid at Room Temperature
• DEGREES OF HARDNESS
• WITH FA LENGTH
• WITH SATURATION OF FA
• The more unsaturated, the more liquid is at room
  temperature      

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Characteristics of Fats in Foods

• Unsaturated fats are more likely to react with
  oxygen and become rancid.
• Food manufacturers may alter fats and oils by
• hydrogenation (high-droh-gen-AY-shun) the
  process of adding hydrogen to unsaturated fat to
  make it more solid and more resistant to chemical
  change. margarine
• antioxidant (anti-OX-ih-dant) a compound that
  protects other compounds from oxygen by itself
  reacting with oxygen.
• Emulsifier a substance that mixes with both fat
  and water and can break fat globules into small
  droplets, thereby suspending fat in water.

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Hydrogenation Stability

• Conversion of liquid oils into semisolid fats
• Improves oxidative stability
• Improves thermal stability
• Increases flavor stability

Trans Fats invented as scientists began to
"hydrogenate" liquid oils so that they can
withstand better in food production process and
provide a better shelf life
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The Trans Fatty Acid

• Trans fatty acid a type of fatty acid created
  when an unsaturated fat is hydrogenated.
• Found primarily in margarines, shortenings,
  commercial frying fats, and baked goods.
• Trans fatty acids have been implicated in
  research as culprits in heart disease.

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Trans Fats

• Associated with increased risk of coronary heart
  disease
• metabolic studies a 1994 estimated 30,000
  premature CHD deaths annually could be
  attributable to consumption of trans fatty acids
• A 1995 review sponsored by the food industry
  concluded that the evidence was insufficient to
  take action and that further research was needed
• Because of the weight of the evidence, the FDA
  now requires including trans fatty acid content
  on the food label

Willett WC, Ascherio A. Trans fatty acids Are
the effects only marginal? Am J Public Health
1994 84722-724.
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Trans Fat in Diet
Processed foods and oils provide approximately
80 of trans fats in the diet, compared to 20
that occur naturally in food from animal sources.
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McDonalds forced to change
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New York City - NO trans fats in
restaurantshttp//www.nyc.gov/html/doh/html/cardi
o/cardio-transfat.shtml
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Fatty Acids in Dietary Fats Oils
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Other Lipid Family Compounds

• Important components of cell membranes.
• Can serve as emulsifiers in the body, joining
  with both water and fat.
• Also used in foods such as margarine, chocolate,
  salad dressings, and frozen desserts to keep the
  fats dispersed.
• Widespread in foods.

P-compound
Phospholipid
e.g. Lecithin Phosphatidyl Choline
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Other Lipid Family Compounds

• Sterols such as cholesterol
• Incorporated as an integral part of the structure
  of cell membranes.
• Used to make bile for digestion.
• Used to make sex hormones (estrogen and
  testosterone).
• Made into vitamin D
• Deposited in the artery walls, leading to plaque
  buildup and heart disease.

Sterols such as cholesterol have a
multiple-ring structure.
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Good Fats/Bad FatsThink Blood, Brain and Heart

• BAD
• raise LDL
• lower HDL "good cholesterol
• Saturated
• Sources Meat, dairy, eggs and seafood (Animal)
  coconut, palm oil (Plant)
• Trans
• Sources Fried foods, processed foods with
  hydrogenated oils

• ?GOOD
• lower total cholesterol
• lower LDL bad cholesterol
• Monounsaturated
• Sources Nuts, canola, olive oil
• Polyunsaturated
• Sources Seafood (Animal), Corn, soy, safflower,
  sunflower (Plant)
• Omega 3s polyunsaturates

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Health Benefits from Lipids

• Cardiovascular health
• Infant nutrition memory enhancement
• Body weight management
• Natural defense

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Lipids in Foods

• Visible
• Oils
• Salad dressings
• Spreads
• Butter
• Margarine
• Mayonnaise

• Invisible
• Meats (between muscle)
• Nuts
• Olives
• Seeds

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Fat Composition of Foods

• FOOD ITEMS OF FOODS
• Oils, Shortenings 100
• Butter, Margarines 80
• Nuts 60
• Peanut Butter, Bacon, Doughnuts 50
• Cheese, Beef, Roasts 35
• Lunch Meats, Hot Dogs 30
• Lean Pork, Ice Cream, Cakes, Pies 13
• Most Fish, Lean Lamb 8
• Milk, Shellfish 0-4
• Bread, Fruit, Vegetables 1

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Consumption

• Dietary Guidelines 2005 Recommended total fat
  intake between 20 and 35 of calories for
  adults.
• A HIGH intake of fats and oils (gt 35 of
  calories)
• generally means increased saturated fat intake
• makes it more difficult to avoid consuming excess
  calories
• A LOW intake of fats and oils (lt 20 of
  calories)
• increases risk of inadequate vitamin E and of
  essential FA
• may contribute to unfavorable changes in
  high-density lipoprotein (HDL) blood cholesterol
  and triglycerides

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Labeling of Fats

• NEW LAW into effect Jan. 1, 2006
• Food manufacturers required to list trans fat on
  the nutrition label
• Fat on label includes
• saturated fat
• trans fat
• cholesterol

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Choosing fats
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Functions of Lipids in Foods

• Texture
• Consistency and mouthfeel
• Viscosity
• Shortening of baked products
• Flavor (including aroma)
• Satiety
• Carrier for fat soluble vitamins
• Heat transfer medium (frying)

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Fat Replacer - Benefat
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Fat Replacer - Olestra

• Derived from vegetable oils and sugar
• Combined in such a way that the body cannot break
  them down
• Sold under the brand name Olean
• Does not contribute calories to food

Can prevent absorption of some nutrients. Thus,
the FDA requires all products made with it to be
fortified with fat-soluble vitamins
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