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