1. Lipids: Nature’s Flavor Enhancers

2. Lipids…
a category of organic compounds that are insoluble in water and have a greasy feel.

3. Pringles Regular Pringles 150 9 2.5 $1.00 Light Pringles 70 $2.58
Calories
Fat
Satur-ated Fat
Cost
Regular Pringles
150 9
2.5
$1.00
Light Pringles 70
$2.58

4. Terms used for lipids:
Fat
Oil
Shortening
Grease
Cholesterol

5. Lipids, like carbohydrates, contain carbon, hydrogen, and oxygen.
But lipids do not provide structure to food products and they cannot dissolve in water.

6. Three general types of lipids in foods and the human body…
Triglycerides
Phospholipids
Sterols

7. Most lipid molecules found in foods and the body have two basic parts.
The base or core is a glycerol molecule called glycerides.
The second part of most molecules is called a fatty acid.

8. Glycerides – 1st type of lipid
Monoglycerides – is a glycerol with one fatty acid attached at the site of a hydroxyl group.
Diglycerides – is a glycerol with two fatty acids attached.
Triglycerides – have a fatty acid joined at each of the three hydroxyl sites.

9. Fatty Acids… are organic molecules that consist
of a carbon chain with a carboxyl
group at one end.

10. Phospholipids- 2nd type of lipid
A second basic type of lipid that has a glycerol base with two fatty acids AND a phosphorus-containing acid attached.
The fatty acids are soluble in water.
This allows phospholipids to mix with both water-based and fat-based substances.

11. Phospholipids- 2nd type of lipid
Phospholipids help carry fats back and forth across cell membranes into the water-based fluids.
In food products, phospholipids keep foods like mayonnaise from separating.

12. Sterol – 3rd type of lipid
Complicated molecules derived or made from lipids.
Examples: cholesterol, vitamin D, steroid hormones.
Cholesterol is a part of every cell in the human body.

13. To understand the effects of lipids in food mixtures,
you need to understand
the ways lipids are categorized.

14. Lipids are grouped according to:
molecular structure
physical state at room temperature
dietary sources

15. Molecular Structure (category)
One way to categorize lipids is by how
saturated their carbon chains are
with hydrogen atoms.

16. Molecular Structure (category)
Each carbon atom is capable of forming 4 bonds.
A carbon atom can bond twice to another carbon atom. This is called a double bond.
Fatty acids will have 0, 1, or multiple double bonds.

17. Molecular Structure (category)
When fatty acids have the maximum number of hydrogen atoms, they are saturated.
Examples: butter, shortening, coconut oil

18. Molecular Structure (category)
Fatty acids that have one double bond in the carbon chain are called monounsaturated.
Examples: olive oil, almonds, walnuts, canola oil

19. Molecular Structure (category)
Polyunsaturated fatty acids have two or more double bonds in the carbon chain. Each double bond bends the fatty acid chain. Bends make it difficult for the molecules to pack together tightly.
Examples: safflower, sunflower, and corn oil

20. Physical State (category)
Lipids that are solid at room temperature are called fats.
Lipids that are liquid at room temperature are called oils.

21. Physical State (category)
Hydrogenation – adding hydrogen atoms to an unsaturated fat to increase its saturation level.

22. Physical State (category)
Advantages of hydrogenated vegetable oil:
Longer shelf life than oil
Greater stability than lard
Costs less than lard
Faster dissolving and setting properties in chocolate

23. Food Source (category)
Milk fats come from the milk of cows or goats.
Lauric acids come from palms of coconut.
Vegetable butters come from seeds of tropical plants.
Oleic-linoleic acids come from corn, peanuts, sunflowers, or olives

24. Food Source (category)
Linolenic acid comes from soybeans and wheat germ.
Animal fats are found in meat and poultry.
Marine oils come from fish.

25. Functions of Lipids in Food Preparation
Transfer heat
Tenderize
Aerate (add air to a batter)
Enhance flavor
Lubricates
Liquids in emulsions

26. Functions of Lipids in Food Preparation
Transfer heat – lipids will continue to increase as heat is added; every lipid has a smoke point and a flash point.
Smoke point – temperature at which the fatty acids begin to break apart and produce smoke.
Flash point – temperature at which lipids flame.

27. Functions of Lipids in Food Preparation
Tenderize – fats tend to shorten the long protein strands of flour of most baked goods, thereby, tenderizing the baked good.

28. Functions of Lipids in Food Preparation
Aerate (add air to a batter) – saturated fat has the ability to allow tiny air pockets to form when batters are beaten sufficiently. If over-beaten, fat could melt and then air pockets are lost.

29. Functions of Lipids in Food Preparation
Enhance flavor – fats add flavor, helps transfer and intensify flavor. Examples: Butter adds flavor to bread; onions and garlic cooked in fat will be stronger than if cooked in a broth base.

30. Functions of Lipids in Food Preparation
Lubricates – makes food seem moister and easier to chew.
Examples: Marbling in meat; mayonnaise spread on sandwiches

31. Functions of Lipids in Food Preparation
Liquids in emulsions – usually one of two liquids in an emulsion – a mixture that contains a lipid and a water-based liquid.
Examples: mayonnaise; bottle salad dressings

32. Lipids in Your Diet - Functions
Concentrated source of energy – 9 calories / gram
Cell production – cell walls made of lipids and proteins

33. Lipids in Your Diet - Functions
Temperature regulation – fatty tissue insulates and holds body warmth
Helps transport vitamins – some vitamins needs fat to be transported

34. Essential Fatty Acids Fatty acids that the body cannot produce:
Linoleic acid
Linolenic acid
Both of these are polyunsaturated
Both are found in most plants and fish oils
Essential for growth and development

35. Role of Cholesterol
Used to build cell membranes – it is a rigid molecule that helps solidify cell walls; adds stability to cell’s structure
Body makes cholesterol from lipids

36. Atherosclerosis
Results when there is too much cholesterol in the blood
Too much blood cholesterol causes deposits called plaque.
The rigidity of the cholesterol plaque deposits on the walls of arteries hardens the arteries. This hardening is called atherosclerosis.

37. Lipoproteins These are clusters of lipid and protein molecules.
Transports cholesterol throughout the body
LDL (Low-density lipoproteins) carry cholesterol from the liver
HDL (High-density lipoproteins) find unneeded cholesterol and return it to the liver.
LDL and HDL work together to keep cholesterol in balance.

38. Lipoproteins
Too much LDL can clog arteries, increasing risk of heart attack or stroke.
High levels of HDL seem to help protect against heart attack and stroke.
Important recommendation – eat a reasonable amount of the right kinds of lipids.