Food oils Flashcards
(20 cards)
what is a triglyceride?
glycerol and 3 fatty acids
are vegetable oils liquid or solid at room temperature?
liquid
what is the composition of fatty acids in northern climates?
higher polyunsaturated fatty acid content
what is the composition of fatty acids in southern climates?
higher monounsaturated fatty acid contents
what forces hold the triglycerides together?
van der Waals forces
do longer chain fatty acids have a higher or lower boing point?
higher
do saturated fatty acids have higher or lower boing points?
higher
which has a higher boiling point, monounsaturated or polyunsaturated fatty acid?
monounsaturated
which oils dominate trade?
palm and coconut oil
is palm oil saturated or unsaturated?
saturated
where is the largest producer of edible oils?
Indonesia
what is hydrogenation?
hydrogen is added across the double bond in the presence of a nickel catalyst- makes margarine
what vitamins are found in oils but are lost when refined?
vitamin E- Tocopherols
dehulling seeds?
grater or friction removes the outer coat which is used for animal feed
mechanical extraction
seeds are crushed filtered and cold-pressed.- makes peanut and olive oil
chemical extraction
immersed in a solvent (hexane) and distilled at 85C to remove the solvent. - also removes the impurities
neutralization
add phosphoric acid and sodium hydroxide, spin in a centrifuge. wash and then filter
bleach
remove colour that would transfer to the food
steam
inject with steam at 270C
winterizing
oil cooled slowly to form crystals and remove triglycerides with high melting points
