Class Notes (835,926)
Canada (509,504)
HLTH 230 (50)
Lecture 4

Fatty Acids (week 4).docx

14 Pages
82 Views
Unlock Document

Department
Health Studies
Course
HLTH 230
Professor
Jeffery Lalonde
Semester
Fall

Description
Intro  Well balanced diet needs some fat  Fat provides mouth feel  Fat soluble vitamins  Fats are made from carbon, hydrogen, and oxy gen o Poor health  Too much fat  Too little fat  Too much of certain kinds of fat Lipids  Contain o Tryglycerides (fats and oils)  Contains 1 glercol molecule  3 fatty acids  fatty acids can be 4 – 24 carbons long  18 carbon fatty acids are most common in foods  o Phospholipids o Sterols  Characterized by insolubility in water  Being able to dissolve in water  Fats o Lipids that are solid at room temperature  Oils o Lipids that are liquid at room temperature Fatty Acids  Saturated (stronger, need less bonds) o Carries maximum number of hydrogen atoms o Composed of triglyercides o Most fatty acids are saturated  Coconut oil  Palm oil  Unsaturated (weaker, need more bonds)  Has a double bond  Lacks hydrogen atoms o Monounsaturated MONO – ONE DOUBLE BOND  Found in milk  Has one double bond  Lacks hydrogen atoms o Polyunsaturated MORE THAN 1 DOUBLE BOND  Fatt acids such as 0mega 3, 0mega 6  Linolenic (omega 3)  Has first double bond 3 carbons away from methyl end  Linoleic (omega 6)  Essential fatty acids  Has first double bond 6 atoms away from methyl end  Must be found in the diet  We cannot make these  Fatty acid that’s lacks 4 or more hydrogen atoms  2 or more double bonds between carbons  Fatty acids o Organic acid chain of carbon atoms  Acid group (COOH) at one end  Methyl group (CH3) ay the other end  Length of Fatty Acid Carbon Chain o Most naturally occurring fatty acids contain even numbers of carbons  18 carbon fatty acids are most common in food supply  stearic acid is simplest  18 carbon fatty acid  all bonds are the same between carbons o Long chain fatty acids are most common in the diet  12 – 24 carbon  Meat, seafood, vegetable oils o Medium chain  6 – 10 carbons o Short Chain  Less than 6 carbons  Mostly in dairy products o 95% of lipids in foods are triglycerides o 99% of the lipids in body are triglycerides o Lipids are usually in the form triglycerides Triglycerides  Formed by a series of condensation reactions o Hydrogen from glycerol joins with hydroxyl from a fatty acid o Molecule of water is formed  Bond formed between glycerol and fatty acid Degree of Unsaturation  Effects stability of fatty acid  Effects firmness of fatty acid o Unsaturated fatty acids lack hydrogen o Have atleast 1 double bond  Firmness o The more unsaturated, the less firm o Length of carbon chain  Smaller carbon chain  Less firm o Plants oils, cocoa butter, palm oil are softer than animals fats  Shorter chain lengths (8-14 carbon)  Stability o Oxidation  Substance combining with oxygen  Produced chemical compounds, rancid smell and taste o Which fats are prone to oxidation  Polyunsaturated  Spoil more easily  Decreased stability because of double bonds  Saturated fats are most resistant to oxidation  Protecting against oxidation o Protect against the environment  Sealed air tight containers o Refrigerate out of light o Add antioxidants  Antioxidants compete for oxygen and protect oil  Vitamin E, BHA, BHT o Hydrogenation  Saturate some or all points of unsaturation by adding hydrogen  Chemical process by which hydrogens are added to monounsaturated and polyunsaturated fatty acids  Reduces double bonds  Makes fats more saturated and solid  More resistant to oxidation  Increases shelf life  Alters texture of the food  Liquid vegetable oils more solid o Eg spreadable butter  Trans fats o Polyunsaturated fat is rarely hydrogenated completely  Some double bonds remain  Change formations  Cis formation  Trans formation o Small amounts of trans fats are found in milk and meat products  Conjugated linoleic acid o Cis double bonds  Most common double bonds  Hydrogens are beside each other on the double bond  Curved U shape o Trans fatty acids  Found naturally in small amounts  Hydrogens are on opposite sides of the double bond  Only partially hydrogenated  Hydrogen shifts around o Increased trans fats is linked to bad cholestrol  LDL o Also decreases HDL (good cholesterol o Limiting trans fats improve blood lipids  Lowers risk of heart disease Dietary Fats  Saturated fatty acids o Butter, lard, coconut oil, beef fat  Monounsaturated Fatty Acids o Olive oil, canola oil, peanut oil  Omega 6 polyunsaturated fatty acids o sunflower oil, corn oil, (seed oils)  Omega 3 polyunsaturated fatty acids o Fish oil, flax seed o Pills, good for your heart 3 Classes of Lipids  Triglycerides  Phospholipids  Sterols Role of Triglyceride  3 fatty acids and 1 glycerol  Provides energy o Come from diet or body stores  Insulate the body - fat is a poor conductor of heat  Natural shock absorbers providing a cushion for bones and organs Phospholipids  Lecithin o Eggs, liver, soybeans, wheat germ, peanuts  Similar to triglyceride o Contains a phosphate group o Nitrogen containing compound instead of one of the fatty acids  Soluable in water, and fat o Fatty acid makes it soluble in fat o Phosphate allows it to dissolve in water  Eg salad dressings  Used to mix fats with water o Mayo and chocolate bars  Part of the cell membrane o Helps lipids move across cell membraine o Enables fat soluble substances such as vitamins and hormones to move easily in and out of the cell o Emulsifier  Keep fats suspended in the blood and body fluids  Benefits o Lecithin is made by the liver o Hydrolyzed in the intestine by lecithinase o We break it down Sterols  Contains 4 ring carbon structure  Variety of any side chain attached o Cholesterol  Most foods derived from animals  Found in foods o Those that come from plants and animals  Phytosterols o Plant sterols o Plant derived compounds, similar to cholesterol o Lower blood cholesterol by competing with cholesterol for absorption  Sterols  Stanols  Sterols in the body o Bile acid – preparing fat for digestion o Sex hormones o Adrenal hormones o Vitamin D o Cholesterol  Cholesterol is a structural component of cell membranes  Can serve as a starting material for compounds  Body makes more cholesterol (endogenous) o Compared to what is eaten (exogenous)  Cholesterol is harmful when it forms deposits on the artery walls o Contributes to plaque formation o Plaque leads to atherosclerosis o Good cholesterol is HDL  A way the body transports cholesterol  Atherosclerosis o Artery disease o Plaque on the inner walls of arteries  Phytosterols lower cholesterol levels by 15% o 2 grams of phytosterol per day  Margarine  Yogurt drinks  Too many calories in diet to make up enough cholesterol Digestion of Lipids  GI Tract receives o 100g of triglycerides o 8g of phospholipids o 350mg of cholesterol  Lipids are hydrophobic o water fearing  Enzymes that digest fats are water loving o Keep fats mixed with watery fluids in GI tract o Break apart triglycerides into smaller molecules that the body can use  Monoglycerides, fatty acids, glycerol)  Hard fats melt at body temperature  Lingual Lipase o Released by salivary glands o Digest short and medium chains  Fatty acids in milk o Important for infants who need milk  Stomach o Strong muscle contractions prevent fat from floating on top of other things in the stomach o Churning grinds solid pieces into finer particles and disperse fats into small droplets o Lingual lipase is acid stable o Gastric lipase  Breaks down fat droplets  Works best in acidic environment in the stomach  Works on outside long chain fatty acid  Left with diglyceride and free fatty acid  Minor role in digestion  Small Intestine o Most of hydrolysis of triglyceride takes place here o Fat particles move from stomach to small intestine o Chyme in small intestine signals release of CCK  Triggers gallbladder to release bile o Bile  Contains bile acids made from the liver from cholesterol  Bile acts as emulsifier  Draws fats into water fluids  Fat digesting enzymes act on the suspended fat droplets  Bile is reabsorbed from the small intestine and recycled.. OR
More Less

Related notes for HLTH 230

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit