NSD 115 Lecture 2: Food Science Notes con.

8 Pages

Nutrition Science & Dietetics
Course Code
NSD 115

This preview shows pages 1,2 and half of page 3. Sign up to view the full 8 pages of the document.
Food Science Notes 2 Hydrogenation o In order to protect fats from becoming rancid and to increase the shelf-life of foods containing fats, food manufacturers use a process know as hydrogenation o Hydrogenation—a process in which hydrogen atoms are added to the carbon-carbon double bonds of unsaturated fatty acids, making them more saturated o Trans Fatty Acids -- During the process of hydrogenation, trans fatty acids are created Good Sources of Fats -- Tree nuts, Avocados, Coconut oil, Walnut oil, Flaxseeds and flaxseed oils, Grass-fed beef and dairy, Wild-caught fish Phospholipids o Can mix in both water and fat o Present in small amounts in food and in the body o Lecithin is the most common phospholipid o Lecithin is made in the liver, therefore it’s nonessential o Lecithin is a major constituent of cell membranes o Lecithin in foods is used as an emulsifier Sterols In plants o Plant sterols o Help form the cell membrane of plants In animals o Cholesterol (found in animal products) o Made in the liver, therefore it is nonessential o Used to make: o Cell membranes o Myelin sheaths o Vitamin D o Bile acids o Cortisol, testosterone, estrogen Dietary Cholesterol Sources – animal products Lipid digestion, absorption and Transport Lipid Digestion o Fats are hydrophobic (afraid of water so don’t mix with water) o Digestive enzymes are hydrophilic (mix well with water) Goal of fat digestion o Dismantle (take apart) triglycerides o Monoglycerides, fatty acids, and glycerol backbone Digestion of Fat in the Stomach o Gastric lipase o Activated by an acidic environment o Acts on triglycerides containing short- and medium-chain fatty acids Digestion of Fat in the Small Intestine o Primary site of fat digestion o Bile acid released -- Emulsifies digested fat o Pancreatic lipase – enzyme used to break down fats o Fat is broken down o To monoglycerides and fatty acids Absorption of Fat o 95% of dietary fat is absorbed o Diffused into the absorptive cells o Short- and medium-chain (<12 C) fatty acids o Are water soluble o Enter the portal system o Long-chain fatty acids re-form into triglycerides o Not water soluble o Enter the lymphatic system Carrying Fat in the Bloodstream o Water (blood) and oil (fat) are incompatible o Unique system of fat transportation is needed -- Lipoproteins There are four types of lipoproteins o Chylomicrons o Very-low-density lipoproteins o Low-density lipopr
More Less
Unlock Document

Only pages 1,2 and half of page 3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

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

Sign up

Join to view


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.