nfsc 303 mccafferty

NFSC 303McCafferty

LIPIDS: Fats and Oils

Functions of lipids

Source of EFAs

linoleic acid

alpha-linolenic acid

Food:

Classification of Lipids

TriglyceridesPhospholipidsSterols

Triglycerides

“Fat”

90-95% lipid in the body

Glycerol: Fatty Acids:Hydrocarbon chains

with acid group at one end HONC rule Saturated: holds all the H’s it can (no

double bonds) Monounsaturated: Polyunsaturated:

Triglycerides can contain all 3 types of FAs

In food, fats that are mostly saturated

are ______________ at room temp.

Mostly unsaturated fats

Except

(pretty saturated!)

Hydrogenation

Chemical process of adding

hydrogen atoms to unsaturated fatty

acids to make them

_________________________

Hydrogenated fats:

Hydrogenation

But, hydrogenation trans fatty acids

Omega-3 Fatty Acids (3)

(Unsaturated 3 carbons in from “omega”

end)

Interest:

Societies (Japan, Alaska, Greenland) that

consume diets high in 3s have heart disease

blood TG levels

may b.p.

thromboxane levels (clotting factor)

Sources: cold water “fatty” fish Albacore tuna cod salmon halibut Shrimp

Also: flax (seed)

AHA recommends fish be a regular part of the diet: ______________

Fish oil capsules

Claims: cure arthritis prevent cancer reverse heart disease boost immune system

Potential Problems: 3FAs are extremely vulnerable to

oxidative damage

Overdoses can impair immune function

Even doses can LDLs—(so do large 7oz daily servings of fish – moderation)!

Potentially toxic levels of vitamins A&D

$$

Evidence:

Lipids

Triglycerides Glycerol Fatty Acids

Trans FAOmega 3 FA

• Fish oils• Flax

PhospholipidsSterols

Phospholipids

Soluble in water:

Soluble in fat: Hydrophilic end (__________________) and Hydrophobic end (___________________) Emulsifiers –

E.g. lecithin in eggoil & vinegar vs. mayonnaise dressing

Lipids

TriglyceridesPhospholipidsSterols

Cholesterol

“Sterol” = Complex alcohol with 4-ring structure

Necessary component of

Major part of plaque

Fat Substitutes

Read labels - kcals

benefit:

Starch derivatives, fibers and gums

Simplesse – frozen desserts – milk and egg white protein product

Olestra –

binds to fat-sol vitamins &

phytochemicals,

GI problems

Approved by the FDA with warning label

describing potential side effects