Fats and Oils

1 Fats and Oils

Outline

Fats
- Structure, Classification, Properties

Energy

Olestra

2 Food Labels

FDA site explaining "new" Food Labels

3 Food Pyramid

4 Fats (Lipids)

Mostly insoluble in water


fatty acids	triglycerides	steroids

5 Lipid Functions

Uses
- Fuel ( ~ 3 month supply)
- Membranes
- Protective function
- Chemical signals, vitamins, and pigments

6 Fatty Acids

Saturated

Doesn't contain any C=C

Formula = CH₃(CH₂)_nCOOH

Unsaturated

Contains one or more C=C

Geometry about C=C is naturally cis

7 Partial Hydrogenation

Removes some (not all) C=C from compound

Purpose

Improve texture and shelf-life

Can produce trans-fatty acids, which may (or may not) lead to cancer

Argument claiming these fats are 'Safe'

Argument claiming these fats are 'Unsafe'

8 Stearic Acid

Stearic Acid has the formula: CH₃(CH₂)₁₆COOH

It is a saturated fatty acid.

9 Oleic Acid

Oleic Acid has the formula: CH₃(CH₂)₇CH=CH(CH₂)₇COOH

It is an unsaturated fatty acid.

Geometry around C=C is cis.

10 Good Fat?

Our bodies cannot synthesize all of the different types of required fats.

These are essential fatty acids.

Diets high in Omega-3 fatty acids appear to have significant health benefits.

Omega-3 fatty acids are unsaturated fatty acids.

For a short summary of health benefits, see About.com

11 Cholesterol

Cholesterol is composed of four fused rings.

All steroids have this same 4-ring core.

12 Good vs. Bad Cholesterol

Cholesterol is a single molecule. It does NOT have a ``good'' and a ``bad'' form. ``Good'' and ``Bad'' refer to the cholesterol carrier.

VLDL: Very Low-Density Lipoprotein - Bad
Transports cholesterol from liver to tissue.

LDL: Low-Density Lipoprotein - Bad
Further transport cholesterol to tissue.

HDL: High-Density Lipoprotein - Good
Transports cholesterol from tissue to liver for ``disposal''.

13 Membranes

This ``cartoon'' represents some of the important aspects of cellular membranes. The surface interacts well with water, but the interior is NOT water-soluble.

14 Lipid Bilayer

15 Fuel Value

The following are ``standard'' values for different classes of foods. Note that a Nutritional calorie is equal to 1000 ``scientific'' calories.

	Fuel Content	Average Supply

Carbohydrates	~ 4 Cal/gram	~ 1 day
Fats	~ 9 Cal/gram	~ 3 months
Proteins	~ 4 Cal/gram	?

16 Combustion

Sugars:

C₆H₁₂O₆ + 6 O₂ ® 6 CO₂ + 6 H₂O

6 O₂ / 6 carbons = 1 O₂ per C atom

Fats:

CH₃(CH₂)₁₆COOH + 26 O₂ ® 18 CO₂ + 18 H₂O

26 O₂ / 18 carbons @ 1.4 O₂ per C atom

17 Olestera

Dave Woodcock's (Okanagan University College) site

File translated from T_EX by T_TH, version 3.02.
On 31 Mar 2003, 16:44.