Vegetable Oils Flashcards
Plant lipids
- Fats and oils (liquid at room temp)
- Fatty acids FA on glycerol backbone
Glycerol
3 carbon alcohol
Fatty acid
Long hydrocarbon chain with carboxylic acid at end
Triglyceride
- 3 FA chains on glycerol
- How humans store fat
How many Fatty Acids are known in plants?
Over 300
The most common Fatty Acids have how many carbons>
- 16-18
What is the function of Fatty Acids in plants?
- Found in leaves, fruits, seeds
- Part of composition of cell membranes
- 6 FA’s account for 95% found in membranes
Where does most commercial cooking oil come from? Why is it concentrated there?
- Seeds
- Oil bodies found in seeds
- Likely due to providing energy for germinating plant
What are 2 ways seeds provide energy to germinating plants?
- Starch
- Oil and fatty acids
Saturation of FA’s
- Number of single carbon to carbon bonds
- Saturated with hydrogen
Unsaturated fats
- Double carbon bond
- Causes less hydrogens in FA
- Can be mono, or polyunsaturated
Chemical effect of saturation (unsaturation)
- Saturated FA has higher melting point
- Shortening, fat, coconut and palm ‘oil’, cocoa butter
Chemical effect of unsaturated FA
- Unsaturated FA molecule has bend at carbon double bond
- Lower melting point = fluid at lower temperature (i.e. oil)
Why is there different saturations in plants?
- Plants don’t maintain overall metabolic temperature
- Fluidity is important in membrane functions (cellular events)
- Plants vary in cold tolerance
- Plants have more unsaturated FA than animals
- Having membrane lipid fluids in a range of temperatures can meet different environmental conditions
What kind of fats are linked to heart disease?
- Saturated
What type of oil lowers blood cholesterol, in general?
- Polyunsaturated oils
What oil raises good HDL and lowers LDL?
- Mono-unsaturated oils
What are the essential FA’s widely present in diet?
- Linolenic, arachidonic, linoleic
What does the type of oil (sat vs. unsat) affect in the diet
- Affects ratio of high and low density lipoprotein in blood
Hydrogenation
- Artificial saturation of fatty acids
- Moved CIS Hydrogen configuration to Trans so bends less
- Convert liquid to solid
- Partial hydrogenation to achieve desired texture
Trans vs Cis configuration in fatty acids
- Trans FA linked to increased heart disease
Where do many cooking oils come from?
- plant seeds
- Corn, safflower, sunflower, peanut, soybean
Canola
- Brassica rapa, Brassicaceae, mustard family
- Selective breeding from rape seed for low content of bitter tasting FA erucic acid
Olive, how many varieties, and oldest tree
- Olea europa, Oleaceae, olive family
- 700 plus varieties
- 1600 year old tree dated in Croatia
- Most widely planted fruit tree
- Not frost tolerant
Olive Oil
- Pressed from olive flesh
- Harvest time critical for quality, degree of ripeness
- Quality controlled
How is the quality of olive oil tested? Extra Virgin designation?
- Acidity test
- Extra Virgin designation has < 0.7% free acids
- Absence of 16 official taste flaws determined by taste panel
How is so much Italian extra-virgin olive oil provided?
- Adulterating and ‘upgrading’ product
What are ways to adulter/upgrade Italian extra virgin olive oil?
- Mix in hazelnut oil and low quality olive oil
- Manipulate cheaper vegetable oils with colour and flavour additives
- Olive oil from other countries like Tunisia that are processed in Italy to be labelled Italian
- Other oils processed in Italian refineries and labelled as olive oil
What is an alternative to potentially less than ideal Italian olive oil?
- Spanish olive oil?
Palm and palm kernel oil, plant
- African oil palm, Elaies genesis, Palmaceae, a monocot, principle oil producer
- American oil palm, Eaies oleifera
- Oil from fleshy fruit part of fruit or seed kernel
What are specifics and uses of palm oils?
- Tolerate high temperature for frying
- Texture good for processed foods
- Used as carrier for cosmetic products
- Possible bio-fuel
Where is palm oil extensively cultivated?
- Indonesia and Malaysia
What did UNEP declare as the leading cause of rain forest destruction?
- Cultivation of palm oil
- Threatens habitats of endangered animals like Sumatran orang-utan (6300 left)
