Chapter 8 Flashcards
What are the functions of fats and oils in food
Flavor, texture and shortening agent
Fish oil and algae
Used as a dietary supplement of omega 3s
Shortening
Is made from 100 percent fat
Margarine
Contains less than 80 percent fat. A water in fat emulsion
Spread
Lowest in fat and contains mostly air and water usually 10 percent fat
Chain length
Longer the chain the higher the melting point
Degree of unsaturation
Lower melting point than saturated fat . Contains more double bonds
Cis vs trans double bonds
Cis double bonds have a lower melting point
Fatty acids are found in what form ?
Triglycerides. Fatty acids are rarely found free form
Plant food (oil) vs animal food (oil)
Plant food tend to have more saturated fat while animal food have more unsaturated fat
Exceptions : tropical plants and fish
Smoke point
Temperature where fat/oil first emit smoke. Usually do not boil but instead Triglycerides become unstable
Fats with low smoke points (not suitable for frying )
Butter (260 f) , lard (370f ), olive oil (375f ), coconut (350 f)
Flash point
Temperature at which volatile hydrolysis within superheated fat and oil can be ignited
Fat degradation (Hydrolysis)
Caused by water impurities and enzymes in food and results in frothy oil. Can be prevented from not constantly re using oil
Fat degradation (oxidation)
Caused by oxygen. (Unsaturated more vulnerable). Results in plasticky flavors. Can be prevented by adding chelators
Antioxidants
Chemicals that quench free radicals before they can damage other chemicals. Examples: vitamin a , e , c and Citric acid
Why is fat mixed with flour prior to adding ingredients for pastry ?
It prevents the formation of of gluten.
Flaky pastry
Layers separated by open spaces. Prepared by flatten with roller and melt by baking
Mealy pastry
Tender/crumby. The fat completely coats the flour. Minimal gluten formation.
Laminated pastries
Fat is layered into dough. Puff pastry
Drop method
Results in mealy tender product
Roll method
Results in laminated and flaky product
Why is it important to not overwork pastry
Gluten can form and create a gummy texture
Frying advantages
Cooks rapidly with high flavor development. Reaches higher temperature than water and has higher conductivity than air.
Ideal temp (350-400)
Disadvantages of frying
Higher calorie content
What happens when fryer is overcrowded
Temperature drops
Negative effect of oil being too hot or too cold
Cold : longer cooking time and too much oil gets absorbed
Hot: dark on outside before inside gets cooked
