Fats Flashcards
How many kilocalories do you get from 1g of each macronutrient?
9kcal for fat
3.75kcal for carbs
4kcal for protein
Meaning fat is a concentrated source of energy
What is a triglyceride?
Glycerol and three fatty acids.
Diglycerides are less common and have two fatty acids.
What is an unsaturated fatty acid?
A fatty acid with one or more double carbon bond. Monounsaturated or polyunsaturated. Olive oil has oleic acid. 2 double bonds: linoleic 3 double bonds: linolenic 4 double bonds: arachidonic
What is an essential fatty acid?
Essential fatty acids are polyunsaturated. Omega-3 and Omega-6. Nuts, seeds, oils, walnuts and fish.
What is a saturated fatty acid?
No double carbon bonds. All bonds saturated with hydrogen.
Palmitic acid, butryic acid and caprylic acid.
What is hydrogenation?
The process of artificially adding hydrogen to a product to make the fat harder. Can saturate originally UFAs. Destroys all double bonds. Bubbles the gas through. Nickel catalyst
What are trans fatty acids?
They are chemically-altered unsaturated fatty acids to have similar effects to SFAs with nutritional benefit.
Fried food, dairy and margarine have them.
Cow stomachs hydrogenate fatty acids naturally. Frying causes them to form.
What does fat contribute to?
Flavour Texture/Mouthfeel Colour Preservative Heat transfer (frying) Traps air -- aeration Emulsified with water
What is fat useful for in the body?
Insulation in body Protects organs Fat-soluble vitamins Essential fatty acids Satiety
What are the fat-soluble vitamins?
A
D
E
K
What is emulsification?
Using a substance to mix two substances that are immiscible.
Lecithin – soya and egg yolk
Mustard makes vinaigrette (oil and vinegar)
Hydrophilic head and hydrophobic tail.
Water-in-oil emulsion does not separate
What is white fat?
Trex, Cookeen and White Flora
Lard
Shortens food to add crumble
Texture
What problem do saturated fatty acids bring?
Easily deposited in arteries – unhealthy
Fried food, alcohol and smoking increase risk. Free radicals erode layers by oxidation and LDL.
Antioxidant vitamins A, C and E prevent this.
What is the alternative to hydrogenation in food production?
Alternative is rearrangement. Heat to 180* and control cooling. Not very hard finished product.
