5- Lipids 1

7/30/2019 5- Lipids 1

1/3

Question

What are trans fats?

A. Cross-linked fatsB. Rancid fats

C. Fats with fewer double bonds

D. Fats with reconfigured double bonds

E. Cross-dressing fats

Lipids

Do not readily dissolve in water

Types of lipids: Triglycerides

Free Fatty Acids

Phospholipids

Sterols (Cholesterol)

Fats (solid) and oils (liquid) 9 kcal /gm

Triglycerides

Most common form of fats and oils

Fatty acids attached to a glycerol

Fatty Acids

Found in our body and foods

In triglycerides

Saturated fatty acids

Solid form

Unsaturated fatty acids

Liquid form

Fats are composed of both saturated andunsaturated

Fatty Acid Structureomega end

H H H H H H H H H H H H H H H H H O

H-C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C-C-OH

H H H H H H H H H H H H H H H H H

Fatty acids can differ in: Length of their carbon chain,Short-, medium-, or long-chain

Number of double bonds present no double bonds saturated

Carbon chain acid end

Monounsaturated Fatty AcidStructure

omega end

One double bond

H H H H H H H H H H H H H H H O

H-C--C--C--C--C--C--C--C--C=C--C--C--C--C--C--C--C--C-OH


7/30/2019 5- Lipids 1

2/3

Polyunsaturated Fatty AcidStructure

omega end

>2 double bonds

H H H H H H H H H H H H H O

H-C--C--C--C--C--C=C--C--C=C--C--C--C--C--C--C--C--C-OH


Composition of Common Fats and Oils

Hydrogenation of Fatty Acids

Process used to solidify an oil

Addition of H to C=C double bonds

Increases shelf life

Formation oftrans fatty acid

(similar to shape of saturated fatty acid)

Hydrogenation

Cis and Trans Fatty Acids Question

Why are trans fats referred to as badfats?

A. They taste good and thus must be bad

B. They cause cancer

C. They can increase risk for heart disease

D. They lead to obesity

E. They cause diabetes

7/30/2019 5- Lipids 1

3/3

Excessive Trans Fatty Acid Intake

Effects Similar to Saturated FAT

Raises LDL

Lowers HDL Increases risk for cardiovascular disease

Current intake is 3%-4% of total kcal

Text 2.6% (1999 publication)

Recommendation from Institute ofMedicine

Keep to an absolute minimum

On Food Labels

Trans fat in food

PARTIALLY HYDROGENATED VEGETABLE OIL SHORTENING

Typical Sources ofTrans FatQuestion

Which of these foods do you think wouldhave the most trans fat?

A. Butter (FDA data)

B. Whole milk (FDA data)

C. French fries (McDonalds data)

D. Big Mac (McDonalds data)

E. Doughnut (FDA data)

F. Deluxe Breakfast (McDonalds data)

McDonalds Nutrition Facts

Richest Source of Trans fat?

Food trans fat total fat serving

butter 0.3 10.8 1 Tdoughnut 5 18.2 1 each

whole milk 0.2 6.6 1 cup

french fries (McD) 5 20 1 med

french fries (FDA) 7.8 26.9 1 med

Big Mac (McD) 1.5 30 1 each

Deluxe Breakfast 11 61 1 each

Documents

5- Lipids 1