Transcript Dairy PowerPoint

• Worldwide, milk is collected
from animals such as:
– Cows
– Goats
– Sheep
– Yaks
– Water buffalo
• However the US Dairy industry focuses on
the milk produced by millions of cows.
• Water (87.7%) Human beings, as well as
animals require more water than any other
nutrient.
• Lactose (4.7%) Lactose is the main
carbohydrate in milk, also called sugar
though it is not sweet
enough to taste. It can
cause digestive problems
for people who are
lactose intolerant.
• Butterfat (3.7%) Butterfat is the fat portion of
the milk. The more butterfat in the milk, the
richer it tastes.
• Protein (3.2%) Milk proteins are crucial for
making cultured dairy
products and cheese.
• Minerals (0.7%) Milk
is an excellent source
of minerals needed
for growth such as
calcium and
phosphorus.
• Aside from making
milk taste rich,
butterfat is the most
coveted part of the
milk. Dairy products
are largely defined
by the amount of
butterfat they
contain.
Type of
Milk
Butterfat
Content
Whole Milk
Minimum of 3.5
percent
2% milk
(reduced
fat)
2 to 2.5 percent
1% milk (low
fat)
1 to 1.5 percent
Skim milk
(nonfat)
Less than 0.5
percent
• Once the fat levels in the milk are
adjusted, the milk is pasteurized.
• The process of pasteurization heats the
milk to specific length of time to kill
pathogens.
• For instance, milk can be
pasteurized by heating it to
161°F for 15 seconds or 275°F
for 2 to 4 seconds.
• Another type of pasteurization is called
ultra high temperature.
• Ultra high temperature (UHT) heats
milk to 280°F for 2 to 6 seconds,
and then it is sealed in sterilized
containers. As a results, UHT
dairy products do not need
refrigeration until they are
opened.
• Homogenizations permanently and evenly
distributes the butterfat in the milk.
• Milk that has not been homogenized has a
greenish tint and easily separates into a cream
layer that floats to the top of a thin watery
portion.
• During the homogenization process, the
butterfat is broken into very small droplets.
These droplets are so small that they are
no longer able to join together and rise to
the surface of the milk. Another result
of homogenization is that the color
of milk becomes bright white.
• The composition of milk can also be
changed by concentration. Concentration
refers to the process of removing water
from milk. As water is removed from the
milk, the levels of proteins, sugars, and
butterfat increases. The three most
common concentrated milk products are:
This milk has had 60 percent of the water
removed, which yields a thick, rich
product. It is sold canned.
This milk has had 60 percent of the water
removed and a large amount of sugar
added. Sweetened condensed milk is
thick, rich, and very sweet. It is sold
canned and is commonly used in baked
products.
This product is a skim milk that has had
nearly all of the water. The resulting white
powder does not require refrigeration and
has a long shelf life.
• Butter represents the dairy product with
the highest percentage of butterfat.
• Churning cream makes butter. (Churning
is another word for rapid mixing)
• As the cream is churned, lumps of
butterfat emerge and begin to stick
together to form larger and larger pieces of
butter.
• Eventually, a large mass of butter is
produced along with a small amount of
watery liquid. This watery liquid is referred
to as buttermilk.
• Salt is added to
butter to improve its
shelf life. Unsalted
butter does not have
any added salt and
has a short life.
• Individually wrapped, one-pound pieces of
butter typically called butter prints; packed
36 pounds to a case. This pack is popular
with foodservice.
• Individually wrapped, quarterpound sticks; packed four
sticks to a box and 36
boxes to a case. This
pack is commonly sold
in grocery stores.
• Individually portions, such as
cardboard backed patties, foil
wrapped chips and cups.
• Whipped butter is butter that
has been mixed with a gas
such as nitrogen. The added
gas makes the butter soft and
fluffy.
• Cultured dairy products have been made
for thousands of years and remain popular
today.
• They are easily recognized for their sour
taste and moderately thick texture.
• What separates fresh dairy products from
cultured dairy products is the addition of
“friendly” bacteria.
To make cultured dairy products, fresh milk is first
pasteurized to kill any harmful bacteria. Next,
specific strains of bacteria are added to the
warm milk. Milk is nutrient rich, high in moisture,
and has a neutral pH, which makes it a perfect
environment for bacterial growth. As the
bacteria reproduce, they consume the lactose
and produce lactic acid. Therefore, during the
incubation period, the dairy product becomes
less sweet and noticeably more acidic. The
increase in acid also thickens the dairy product.
Once the cultured dairy product reaches the
desired stage of thickness and acidity, it is
refrigerated. The colder temperature stop
bacterial growth, but does not kill the
bacteria. In fact, the labels of many
cultured dairy products indicate that the
cultures are live.
• Buttermilk
– The name buttermilk originally referred to the
watery liquid that remained after churning
butter.
– But now it is skim milk with strains of bacteria
added to make the milk more acidic and to
thicken the liquid.
– Buttermilk is used in baked products and
salad dressings.
• Yogurt
– Yogurt is a centuries old product.
– It is made by adding several strains of
bacteria to warm milk. Once the bacteria
have changed the flavor, texture and acidity
level of the milk, it is often sweetened and
flavored before sold.
– Adding thickeners such as gelatin or pectin to
the yogurt produces some thick varieties of
yogurt.
• Sour Cream
– Is a common product in baked goods and is
served as a condiment for savory dishes.
– Unlike buttermilk and yogurt, sour cream
starts with a high-fat dairy product– light
cream.
– Finished sour cream must have a minimum
butterfat content of 18 percent.
• Worldwide, there
are literally
thousands of
varieties of
cheese.
• Cheese varies
dramatically in
shape, color, and
flavor.
• What separates cheese from cultured dairy
products is the amount of moisture in the
finished product. Cultured dairy products have
the same amount of moisture as milk, while
cheese has less moisture than milk.
• Reducing moisture levels means that the cheese
is less likely to spoil.
• The more moisture removed
from the cheese, the longer it
will last.
• A very dry cheese can last for
years without spoiling.
• Every cheese begins as milk.
• In the U.S., most cheese is made from
cow’s milk; although cheese made from
goat’s and sheep’s milk is becoming more
popular .
• Before cheesemaking begins
the fat level is adjusted
(higher fat cheeses- fat is
added, lower fat cheeses
fat is removed from the milk)
• Bacteria is then added to the milk.
Bacteria increase the acidity, change the
flavor, and thicken the milk.
• A small amount of coagulant (an
ingredient that causes the milk to thicken
dramatically) is added to the milk. The
coagulant that is traditionally
added to the cheese is called
rennet.
The addition of bacteria and rennet turns the
milk into a semisolid mass. The thickened
milk is then cut into cubes. These cubes
which contain casein proteins (one of the
two types of protein in milk) are called
curds. As the curds are drained, mixed
and sometimes heated, they shrink and
whey is expelled. Whey is the watery
portion of the milk that contain the whey
proteins (the other type of protein in milk).
The more whey that is removed from
the curds, the firmer the cheese will
be. Salt is also added to the curds to
remove even more moisture. The
curds are then placed in a mold and
perhaps pressed. As this mass of
curds ages, it will knit together to form
cheese.
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Fresh Cheeses
Soft Cheeses
Medium Firm Cheeses
Hard Cheeses
Blue Cheese
Stretched Cheeses
Processed Cheese
• Are high in moisture and barely aged
• Slightly sweet and milky flavored.
• Since they are high moisture, they spoil
more easily than other cheeses (have a
short shelf life)
• Examples: cream
cheese, cottage
cheese, ricotta
• Have elastic or creamy textures
• When they are well
aged, they can even
become runny
• Examples: Brie,
Camembert and lightly
aged goat cheeses
• Have a drier and firmer texture
• Have a longer shelf life
• Made with curds that are cut
smaller, sometimes the curds are
lightly cooked
• The curds are placed in a mold
and pressed which removed the
whey.
• Medium firm cheeses are aged for
at least a month before being sold.
• Examples: Morbier, Monterey
Jack, Fontina, Colby
• The driest cheese and there for have very long
shelf lives
• Curd is cut into small pieces, cooked at high
temps, and firmly pressed into molds.
• Ages for months or even years.
• Sometimes referred to as
grating cheeses
• Examples: Parmesan,
Cheddar, Swiss, Manchego,
Gruyere
• The blue color in blue cheese is actually a type
of edible mold.
• The mold that grows inside the cheese
intensifies the flavor of the cheese.
• Not all blue cheeses are blue,
the mold can have varying
shades of green, grey
and blue.
• Examples: Stilton,
Gorgonzola, Maytag Blue
and Danish Blue
• Not many types, but the most
popular category of cheese
• To make stretched cheeses,
hot curds are repeatedly
stretched to produce strands of
cheese.
• Stretch cheeses are generally
eaten with little aging and have
an elastic, medium firm texture.
• Examples: mozzarella, string
cheese and provolone
• Vast quantities of processed cheese are eaten
daily in America.
• Most famous member of this
category? American cheese!
• Processed cheese begins with
medium firm or hard cheeses that
are grated and melted. As the cheese melts, it
is mixed with an emulsifier, water and possibly
additional fat.
• The resulting hot cheese paste is then rolled into
singles, formed into blocks or squirted into jars.