Zusammenfassung der Ressource
Plant Oils and Their Uses - C1
- Many plants
produce useful oils
- can be converted into
consumer products
- e.g. processed food
- EMULSIONS
- can be made
and have a
number of uses
- oils don't dissolve in water
- they can be used
to produce
EMULSIONS
- = tiny droplets of oil suspended in water
- thicker than oil or water
- have many uses that depend on
their special properties
- provide better TEXTURE, COATING ABILITY and APPEARANCE
- e.g. in salad dressings, ice creams, cosmetics and paints
- emulsifiers have HYDROPHILIC
and HYDROPHOBIC properties
- EMULSIFIERS MAKE EMULSIONS STABLE
- they have these properties:
- HYDROPHILIC
= water loving
- HYDROPHOBIC
= water hating
- VEGETABLE OILS
- can be hardened to
make margarine
- biodiesel produce
from vegetable oils
- important foods and
fuels because they
provide a lot of energy
- higher
boiling points
than water
- so can be used to cook
foods at higher
temperatures than boiling
- produces quicker cooking and different flavours
- increases energy that the food produces when eaten
- some fruits,
seeds and nuts
are rich in oils
- can be extracted
- the plant material is
crushed and the oil is
removed by pressing
- or, the oils is dissolved in
a solvent e.g. hexane and
the solvent is then distilled
off leaving the oil behind
- water and
other impurities
are removed
- SATURATED and UNSATURATED OILS
- UNSATURATED
- contain
CARBON-CARBON
DOUBLE BONDS
- they are sometimes called
POLYUNSATURATED FATS
- can be detected by
REACTING with
BROMINE WATER
- BROMINE WATER TURNS FROM
ORANGE-BROWN TO
COLOURLESS WHEN IT REACTS
WITH UNSATURED FATS
- can be hardened to
make them spreadable
- by reacting them with
HYDROGEN in the presence
of a NICKEL CATALYST at
about 60°c
- HYDROGEN adds to
the carbon-carbon
double bonds
- HYDROGENATED OILS have
HIGHER MELTING POINTS
- SOLIDS at ROOM TEMP
- useful as spreads and
in cakes and pastries