Topic 5: Part B Flashcards
Butyric acid
found in butter has 4 carbon atoms, single bonds and is saturated
Stearic acid
found in beef has 18 carbon atoms, single bonds and is saturated
Palmitic acid
found in palm oil an cocoa butter has 16 atoms, single bonds and is saturated
Oleic acid
found in olive and canola oil, has 18 carbon atoms, one double bond and is unsaturated (monounsaturated)
Polyunsaturated fatty acids contain more than..
1 double bond
Linoleic acid (omega-6)
has 18 carbon atoms and 2 double bonds. It is found in most foods especially oilseeds such as canola and soybeaN
Linolenic acid (omega-3)
has 18 carbon atoms but contains 3 double bonds and is found mostly in soybean, flaxseed and hempseed
Linoleic and linolenic acids are…
essential fatty acids
CIS trans configuration
- shape of fatty acids is changed by the presence of a double bond since the bond limits the rotation of the carbon atom
- shape that is produced is dependent upon the configuration of the bond
The cis configuration the H atoms are on the ..
same side of the double bond
In the trans confutation the H atoms are on the ..
opposite side of the double bond
Fatty acid shape affects the ..
melting point of the fat or triglyceride
Trans fatty acids have higher..
melting point than the cis fatty acids
Why do fatty acids have higher melting point
Because in the cis configuration the triglyceride molecules can not pack as closely together thus less energy is required to melt the fat
Conversely the trans configuration allows ..
more dense packing of the fatty acids and more energy is required to melt the fat
Evidence suggests that trans fatty acids behave similarly to..
saturated fatty acids in raising levels of body cholesterol and less consumption is recommended
Hydrogenation is the ..
forced addition of hydrogen atoms to the unsaturated bonds in an unsaturated fat
Hydrogenation raises the ..
melting point of the fat
Hydrogenation is use din food industry to harden..
liquid oils into semi solid fats
Hydrogenation makes oil more resistant to..
oxidative rancidity
Linoleic acid becomes biologically inactive when..
converted to the trans form
Trans fatty acids are formed mostly during..
process of hydrogenation
Hydrogenation of oils is carried out too..
- make the oil more solid at room temp (margarine)
- increase the stability (Smoke point) of these oils to thermal temps (frying temp)
Most margarines that are currently sold are not ..
hydrogenated but consist of careful blend of different oils and fats
The consumption of non hydrogenated margarine is..
recommended over hydrogenated type for painting a healthy status
Phospholipids
present in foods in relatively small amounts but play important roles as emulsifying agent
Lecithin is a ..
phospholipid used in various foods including margarine
What is a good source of phospholipids
egg yolk and soybean oil
Cholesterol is best known..
sterol found in animal foods
Sterol
essential component in the body cells but levels get too high in the blood it can lead to heart disease and prevent normal flow of blood (vitamin D)
Plants don’t manufacture what sterols.. but manufacture..
cholesterol; phytosterols
Phytosterols
not well absorbed from the gastrointestinal tract and interfere with absorption of cholesterol
Some types fo food (such as margarine) are fortified with phyosterols to…
help reduce amount of cholesterol absorbed into blood stream
Cholesterol LDL low density lipoprotein
carries cholesterol from liver to body tissues
Cholesterol VLDL: very low density lipoprotein
carries cholesterol and triglycerides from liver to body tissues
Cholesterol HDL: high density lipoprotein
carries cholesterol back to the liver for disposal
Factors that raise LDL and lower HDL should be avoided..
- high fat diet
- high saturated fat diet
- diet high in trans fatty acids
