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Why are there fats in our diets?
They provide energy, they store energy, insulation, protection, transport fat-soluble vitamins. Help satisfy hunger and make food taste good.
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What are lipids?
There are three types of lipids: Triglycerides, Phospholipids, and sterols (cheolesterol). They are not ready to dissolve in water. They are a fat which is solid and oil that is liquid also are macronutrients that provide energy. 9kcal 1gm
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Emulsifier
A compound that can suspend fat in water by isolating individual fat droplets, using a shell of water molecules or substances to prevent the fat from coalescing. Example. Salad dressing- oil and water separate but when agitated (shaking the bottle) the contenants in the bottle emulsify with the fatty acid with the oil in the center surrounded by a water shell.
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What is a fatty acid?
Fatty acids are found in our food (triglycerides). Saturated fatty acids are in solid form. Unsaturated fatty acids are in liquid form.
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What are essential fatty acids and their functions?
- Omega-3 fatty acids (alpha-linolenic acid) an 18 carbon, 3 double bonds.
- Omega-6 fatty acids (linoleic acid)an 18 carbon, 2 double bonds- body can only make the db after the 9th carbon from the omega end
- Function
- Immune function, vision, cell membrane, and production of hormone-like compounds
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What are triglycerides?
The most common forms of fats and oils. The fatty acid attaches to the glycerol.
Glyerol + 3 Fatty Acids turns to Triglycerie + 3 h2O
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Where are phospholipids found, what are there functions and in what foods?
- Located- cell membranes, the body, synthesized as needed, are similar to TG's but phosphate is on 3rd glycerol carbon
- Function- Bile acid, lecithins, improves food products
- Foods- wheat germ, peanuts, yolks, soy beans, organ meat
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What are sterols?
multi-ringed structure, no glycerol backbone, cholesterol is a sterols, waxy substance, found only in animal foods, and like other lipid, they do not readily dissolve in water
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What is cholesterol?
It is produced by the liver, found only in animal products, essential to cell membrane, it forms important hormones: estrogen, testosterone, vitamin D and it a precursor to bile acids.
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Sources of fats?
- Animal based: Butter, Lard, Tallow, Fish oil
- Plant based: Oils- seeds, olives, Products made from oils- margarine, spread, Avocado, Nuts and nut butters
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What are fat substitutes?
- Water- diet margarine and spreads
- Starch derivatives- Z-trim, modified food starch
- Fiber cellulose-maltrin, stellar, oatrim
- Dairy-Lo- Protein globules
- Olestra or Olean (links FA to sucrose)- not digested, FDA approved, fat-soluble vitamin issue
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Rancidity- what is it and how do you control it?
- it is decomposed oils, it is the breakdown of the C=C bonds by UV light and or O2, it has an unpleasant odor and flavor, PUFA more susceptible, it has a limited shelf life.
- control it by hydrogenation, addition of antioxidants- vitamin E, butlated hydroxyanisol (BHA) and butylated hydroxytolune(BHT), ascorbic acid, other preservatives
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What is hydrogenation?
It is the process used to solidify an oil. It is the addition of an H to the C=C db that makes PUFA FA more SFA. It increases the shelf life. Helps in the formation of trans fatty acids (shape is simiar to the SFA)
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