Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper...
-
Upload
abner-poole -
Category
Documents
-
view
213 -
download
0
Transcript of Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper...
![Page 1: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/1.jpg)
Fats in FoodDietary recommendations:• Lower fat intake to 30% of daily calories • Consume “proper amount” of fatty acids
in diet • Have approximately 1:1.5:1 ratio of
saturated, monounsaturated and polyunsaturated fats
• Increase intake of Omega 3 Fatty Acids (may reduce blood cholesterol)
![Page 2: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/2.jpg)
Artificial Fats
Olestra: Substitute for fat. Not a triester or triglyceride. Made from 8 fatty acidsbonded to sucrose by eight ester bonds.
an "octo-ester" Some similarity in structure to fats. Some similar functions (taste, texture, etc.). Differences in structure - enzymes hydrolyzing fats do not hydrolyze
Olestra. Advantage: does not break down, enter bloodstream, & turn into fat. Disadvantage: remains in digestive tract, may reduce vitamin uptake, &
cause anal leakage (oily stool).
![Page 3: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/3.jpg)
Why trans-fats are so bad for us:Natural unsaturated fats usually in kinked "cis" form. Bubbling H2 through polyunsaturated oils makes "partially hydrogenated" fats. Hydrogenation process converts bent "cis" form to straightened "trans" form. Less vulnerable to becoming rancid - longer shelf life. Margarines and shortenings in baked goods & peanut butter.
Exposure to prolonged heat (as in deep fat frying) also creates trans fats by loosening double bond and allowing it to "flip" into the straight trans form.
![Page 4: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/4.jpg)
Partially hydrogenated fats continued:The body recognizes the chemical
structure as the same (isomer) Tries to use it in the same place(s)/ for
the same purposes Trans form stacks together just like
saturated fats, which sabotages the unsaturated oil properties: flexible, porous function
used in cell membranes
![Page 5: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/5.jpg)
Trans fats in Consumer Products:
![Page 6: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/6.jpg)
Chemical Reactions of Triacylglycerols
• Hydrolysis - reverse of esterification– Stepwise: enzyme controlled
• Saponificatioin - hydrolysis in basic sol’n• Hydrogenation
– UFA + H2 --> SFA– Side effect: Cis --> Trans double bonds
• Oxidation – Associated with rancidity– Counteracted by adding antioxidants
![Page 7: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/7.jpg)
Soap molecules will be attracted to non-polar oil and grease molecules on one end, and to polar water molecules on the other end
![Page 8: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/8.jpg)
Keep this structure in mindwhen we discuss cell membranes!
![Page 9: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/9.jpg)
![Page 10: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/10.jpg)
Dead bodies, especially
overweight people, often saponify in
moist environments.Forming
soap mummies!
When the fat of a corpse starts turning into a soap-like
substance it’s called adipocereAka "grave wax" or "corpse cheese".
![Page 11: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/11.jpg)
Major Types of
Lipids
![Page 12: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/12.jpg)
Phospholipids: cell membrane molecules
Three main types of membrane lipids:1.Phospholipids
• Glycerophospholipids• Sphingophospholipids
2.Glycolipids• Sphingoglycolipids
3.Cholesterol
•The Cell Membrane separates cell’s interior from the environment. •80% of a cell membrane is some type of lipid•Most abundant are the phospholipids
![Page 13: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/13.jpg)
Membrane lipids: All have 2 hydrocarbon tails and hydrophilic heads. In the sphingolipids (sphingomyelins and glycolipids) one of the two hydrocarbon tails is part of the alcohol sphingosine.
![Page 14: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/14.jpg)
Cross section of a lipid bilayer. Circles represent polar “heads” of the lipid
Wavy lines represent nonpolar “tails” of the lipid. The “heads” occupy surface positions, and the “tails” occupy internal positions.
phospholipid bilayer separates these 2 watery areas
![Page 15: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/15.jpg)
Cell Membranes: like a micelle but double thick. Double layer of phospholipids = a bilayer.
a “fat sandwich:” fatty acids are the filling, phosphate heads are the "bread.”
![Page 16: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/16.jpg)
Comparison of sphingomyelin & phosphatidylcholine
Both are membrane lipids
containing a ciscis double bond double bond
in one of their hydrophobic tails.
Both have a phosphate and choline in their polar head groups
![Page 17: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/17.jpg)
The kinks associated with cis double bonds in fatty acid chains prevent tight packing of the lipid
molecules at lower temperatures.
Essential to have a fluid membrane
so that nutrients move in and
wastes move out easily from the cell
![Page 18: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/18.jpg)
The cell membrane
Cholesterol, glycolipids, glycoproteins, and other proteinserve various functions:Stabilizing, cell recognition, transport, and attachment points
![Page 19: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/19.jpg)
Tetracyclic skeleton: 3 fused six-membered & one five-membered ring,
Rings are designated A, B, C & D Carbons are numbered as above.
Wide variety of functions in animals & plants.
![Page 20: Fats in Food Dietary recommendations: Lower fat intake to 30% of daily calories Consume “proper amount” of fatty acids in diet Have approximately 1:1.5:1.](https://reader035.fdocuments.in/reader035/viewer/2022062717/56649e2a5503460f94b17577/html5/thumbnails/20.jpg)
Greek chole- (bile) and stereos (solid) - 1st found in gallstones.Steroid derivative lipid, found in the cell membranes.
Transported in blood plasma. Most is produced internally, not dietary in origin.
Cells of liver, spinal cord, & brain have a lot of cholesterol.
Alcohol Group on
C #3
8 C branched chain on
C #17
C=C bond between
C #5 & C #6