TYPES OF FOOD
Fats and oils
Sources of fats and oils
Oils are fats that are liquid at room temperature, although the terms
are often used interchangeably (see p.29). Those that you get
through your food are called dietary fat. Although all fat contains the
same number of calories— 255kcal/oz (9kcal/g)—some sources are
better for you than others. Oils from fish and plants are generally
healthier than animal fats, because they contain more unsaturated
fatty acid chains. But not all unsaturated fatty acids are the same
either. Omega-3 fats are a type of polyunsaturate that tends to be
anti-inflammatory, while omega-6 fats have the opposite effect.
Fats and oils
Demonized in the public perception of healthy eating, the true story
of fats and oils is complex and contradictory; essential to life and
to good food, oils and fats can be superfoods if used properly. The
main types of fat found in food are saturated and unsaturated
fats. Most fats and oils contain both types.
Saturated fats
Saturated fats have been linked
for some time with a higher
risk of cardiovascular disease
(see pp.214–215), but this is
now considered controversial.
Coconut oil, butter, cheese,
and red meat all contain high
levels of saturated fat.
Milling
The olives
are crushed to
release oil. The
resulting paste is
“malaxed” or
mixed to allow oil
droplets to coalesce.
Olives
The riper the olive,
the more oil it will yield,
but flavor deteriorates, so
choosing when to harvest
is a compromise between
the two factors.
Polyunsaturated fats
Unsaturated fat is found mainly in
vegetable oils. Most popular oils,
including sunflower, sesame,
and corn oil, are dominated
by omega-6 fatty acids.
Linseed is a rare
exception that provides
plenty of omega-3.
Monounsaturated oils
Foods rich in monounsaturates
such as olive, canola, sesame,
and safflower oil are associated
with lower levels of bad
cholesterol and reduced risk of
stroke and heart disease.
Stone rollers
grind the olives
to a paste
WHY CAN’T
EXPERTS AGREE WHICH
FATS ARE GOOD OR BAD?
Science in this area rarely
offers clearcut answers; the
best advice is to eat a varied
diet rich in seafood, seeds,
and small amounts of
meat and dairy.
COCONUT OIL
1
2
SUNFLOWER OIL
Paste is collected
Olive press
US_136-137_Fats_and_Oils.indd 136 18/01/2017 09:45
136 137
TYPES OF FOOD
Fats and oils
Milling
The olives
are crushed to
release oil. The
resulting paste is
“malaxed” or
mixed to allow oil
droplets to coalesce.
Pressing
The paste is
spread onto fiber
disks, which are
stacked and
hydraulically
pressed.
Cooking with oil
Oils bring many important features to cooking:
making emulsions; tenderizing food by
permeating and weakening tough structures;
allowing foods to be cooked through frying at
heats greater than the boiling point of water; and
to allow browning reactions. Frying oil declines
in quality as components break down, however.
EXTRA VIRGIN
OLIVE OIL
OLIVE OIL
UNREFINED
SUNFLOWER
OIL
EXTRA VIRGIN OLIVE OIL
UNREFINED
PEANUT OIL
BUTTER
UNREFINED SOY OIL
REFINED
SUNFLOWER
OIL
REFINED PEANUT OIL
REFINED OLIVE OIL
GHEE
REFINED
SOY OIL
REFINED
CORN OIL
UNREFINED
CORN OIL
Heating pipes
Smoking point
Oils have differing smoking points (the temperature at which it
begins to smoke). Above this temperature, the oil degrades and
produces harmful combustion products. Unrefined oils smoke
at lower temperatures, because their impurities begin to burn.
3
Heating and
centrifuging
To extract the
maximum amount
of oil, the paste can
be heated, and the
oil decanted by
centrifugation.
3
Decanting
Pressing produces a
mix of oil and water, which
must be separated by
decanting. Today
centrifugation
is used to
separate
the t wo.
4
Refining
Acidic oils and pomace
extracts from the olives
may be refined through
physical or chemical
means to produce
a palatable oil.
4
In recent years, fat received such
bad press that people turned
to eating low-fat versions
of foods—including
yogurts, preprepared
meals, and salad
dressings. However,
the low-fat or zero-fat
versions often have
higher sugar
content, used to
make the food
palatable.
LOW FAT FOODS
SPAIN IS THE WORLD’S
LARGEST PRODUCER
OF OLIVE OIL
Vegetable
waters
Paste passes
through centrifuge
100˚C 150˚C 200˚C 250˚C 300˚C
200˚F 300˚F 400˚F 500˚F
˚C
˚F
Oil
US_136-137_Fats_and_Oils.indd 137 27/03/2017 11:43
136 137
TYPES OF FOOD
Fats and oils
Milling
The olives
are crushed to
release oil. The
resulting paste is
“malaxed” or
mixed to allow oil
droplets to coalesce.
Pressing
The paste is
spread onto fiber
disks, which are
stacked and
hydraulically
pressed.
Cooking with oil
Oils bring many important features to cooking:
making emulsions; tenderizing food by
permeating and weakening tough structures;
allowing foods to be cooked through frying at
heats greater than the boiling point of water; and
to allow browning reactions. Frying oil declines
in quality as components break down, however.
EXTRA VIRGIN
OLIVE OIL
OLIVE OIL
UNREFINED
SUNFLOWER
OIL
EXTRA VIRGIN OLIVE OIL
UNREFINED
PEANUT OIL
BUTTER
UNREFINED SOY OIL
REFINED
SUNFLOWER
OIL
REFINED PEANUT OIL
REFINED OLIVE OIL
GHEE
REFINED
SOY OIL
REFINED
CORN OIL
UNREFINED
CORN OIL
Heating pipes
Smoking point
Oils have differing smoking points (the temperature at which it
begins to smoke). Above this temperature, the oil degrades and
produces harmful combustion products. Unrefined oils smoke
at lower temperatures, because their impurities begin to burn.
3
Heating and
centrifuging
To extract the
maximum amount
of oil, the paste can
be heated, and the
oil decanted by
centrifugation.
3
Decanting
Pressing produces a
mix of oil and water, which
must be separated by
decanting. Today
centrifugation
is used to
separate
the t wo.
4
Refining
Acidic oils and pomace
extracts from the olives
may be refined through
physical or chemical
means to produce
a palatable oil.
4
In recent years, fat received such
bad press that people turned
to eating low-fat versions
of foods—including
yogurts, preprepared
meals, and salad
dressings. However,
the low-fat or zero-fat
versions often have
higher sugar
content, used to
make the food
palatable.
LOW FAT FOODS
SPAIN IS THE WORLD’S
LARGEST PRODUCER
OF OLIVE OIL
Vegetable
waters
Paste passes
through centrifuge
100˚C 150˚C 200˚C 250˚C 300˚C
200˚F 300˚F 400˚F 500˚F
˚C
˚F
Oil
US_136-137_Fats_and_Oils.indd 137 27/03/2017 11:43
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