Milk is a white nutritious liquid produced by female mammals
for feeding their young. The milk most used in this world is that obtained from
cows. Goats’ milk and ewes’ milk can also be used.
Food value - Milk can make valuable contributions to our daily eating
pattern and can help to meet out nutritional needs as part of a balanced,
varied diet. Milk is one of the most nutritionally complete foods available,
containing a wide range of nutrients, which are essential for the proper
functioning of the body. In particular, milk is a good source of protein,
calcium and B group vitamins, and whole milk is a good source of vitamin A.
Storage
Milk is a perishable product and therefore must be stored
with care. It will keep for four to five days in refrigerator conditions. Milk
can easily be contaminated and therefore stringent precautions are taken to
ensure a safe and good-quality product for the consumer.
- Fresh milk should be kept in the container in which it is
delivered.
- Milk must be stored in the refrigerator (four to five days).
- Milk should be kept covered as it easily absorbs smells from
other foods, such as onions and fish.
- Fresh milk should be ordered daily.
- Tinned milk should be stored in a cool, dry, ventilated
rooms.
- Dried milk is packaged in airtight tins and should be kept
in a dry store.
- Sterilized milk will keep for two to three months if
unopened, but once opened must be treated in the same way as pasteurized milk.
- UHT (ultra-heat-treated) milk, always check the date stamp,
which expires six months after processing, and make sure to rotate stocks. Once
opened it must be refrigerated and will keep for four to five days.
Milk heat treatment and types of milk
Milk is heat in one of several ways to kill any harmful
bacteria that may be present. Approximately 99 per cent of milk sold in the world is heat
treated.
- Pasteurized milk - the milk is
heated to a temperature of at least 71.7°C (161°F) for 15 seconds and then
cooled quickly to less than 10°C (50°F).
- UHT (ultra-heat-treated) milk -
milk is homogenized (see below) and then heated to a temperature of at least
135°C for 1 second, the milk is then packed under sterile conditions.
- Sterilized milk - milk is
pre-heated to 50°C, separated and standardized to produce whole, semi-skimmed
or skimmed milk. Filled bottles are then passed through a steam pressure
chamber at temperatures of between 110°C and 130°C for 10-30 minutes, and then
cooled in a cold water tank.
- Homogenized milk - milk is forced
through a fine aperture that breaks up the fat globules to an even size so that
they stay evenly distributed throughout the milk and therefore do not form a
cream line.
- Whole milk (blue cap) - comes as
pasteurized or pasteurized homogenized, and has a fat content of an average 3.9
per cent.
- Semi-skimmed milk (green cap) -
comes as pasteurized and has a fat content of between 1.5 and 1.8 per cent.
- Skimmed milk (red cap) - comes as
pasteurized and UHT, and contains just 0.1 per cent fat.
- Channel Islands milk - milk that
comes from the Jersey and Guernsey breeds of cow, and has a particularly rich
and creamy taste and distinct cream line; it contains, on average, 5.1 per cent
fat.
- Evaporated milk - a concentrated
sterilized product with a final concentration about twice that of the original
milk.
- Condensed milk - concentrated in
the same way as evaporated milk but with the addition of sugar; this product is
not sterilized but is preserved by the high concentration of sugar it contains.
- Dried milk powder - milk produced
by the evaporation of water from the milk by heat, or other means, to produce
solids containing 5 per cent or less moisture; available as a whole or skimmed
product; dried milk is skimmed milk powder to which vegetable fat has been
added.
- Soya milk - can be offered as an
alternative to vegans and people with intolerance to cows’ milk.
- Goats’ milk - nutritionally
similar to cows’ milk and can be useful for people with lactose intolerance. Did
you know that Goat Milk is superior to Cow Milk? Its benefits include; it’s
easier to digest, it has fewer allergenic proteins and causes less
inflammation, it’s high in calcium and fatty acids but low in cholesterol, it
keeps skin looking good, and it absorbs nutrients and minerals better than
cows’ milk.
- Rice milk - an alternative to
dairy milk for vegans and those with an intolerance to lactose. It is heat
stable, which makes it a good replacement for cows’ milk in cooking although it
tends to have a sweeter taste.
- Coconut milk - is high in
saturated fat but low in calories. It can be served as a drink but is more
often used as a marinade and in cooking.
Milk is used in:
- Soups and sauces.
- The making of puddings, cakes and
sweet dishes.
- The cooking of fish and
vegetables.
- Hot and cold drinks.
Consumption of milk and dairy
products is associated with numerous health benefits. They include;
Bone health - Milk and dairy
products are providers of calcium, phosphorous, magnesium and protein which are
all essential for healthy bone growth and development. Adequate consumption of
milk and dairy from early childhood and throughout life can help to make the
bones strong and protect them against diseases like osteoporosis (a
debilitating, brittle bone disorder) in later life.
Teeth - The amounts of calcium and
phosphorous in milk and dairy products are also beneficial for the development
and maintenance of healthy teeth. The most abundant protein in milk is casein
and is protective as it forms a thin film on the enamel surface which prevents
loss of calcium and phosphate from the enamel when the teeth are exposed to
acids in the mouth. Studies have suggested that milk also reduces the effects
of cariogenic foods on teeth when consumed together with them in the diet. In
fact, dentists recommend that milk is the only safe drink to have between meals
(except for water) as it has been shown not to cause tooth decay even in
conditions perfect for damaging teeth!
Milk and blood pressure - An
increasing number of studies suggest that consuming 3 portions of dairy each
day, along with 5 portions of fruit and vegetables as part of a low salt diet
can reduce high blood pressure in both adults and children. Although the exact
mechanisms involved are not clear, it is thought that the calcium, potassium,
magnesium and proteins within milk are all likely to be involved.
Milk and cardiovascular disease - Several
studies have linked milk and dairy consumption with a reduced risk for
cardiovascular disease. A recent study in Welsh men found that those who drank
the most milk had fewer heart attacks than those who had little or no milk in
their diets. This connection could be due to many factors in milk, but
epidemiological studies have shown that higher intakes of calcium in particular
are linked to a reduced risk of cardiovascular disease. More specifically,
studies have shown that high calcium intakes may reduce high levels of bad
cholesterol in the blood, and increase low levels of good cholesterol both of
which are known risk factors for cardiovascular disease. In addition, it is
also thought that calcium may bind harmful fats together in the gut and prevent
their absorption, which in turn prevents levels in the blood increasing.
Obesity - Contrary to popular
belief, research has shown that people who consume milk and dairy foods are likely
to be slimmer than those who do not. Studies have also shown that consumption
of milk and dairy foods as part of a calorie controlled diet is associated with
increased weight loss, particularly form the abdomen. This is particularly
beneficial since excess fat around the trunk region of the body is associated
with greater risks to health. The precise mechanisms involved are unclear but
are likely to involve calcium which is found in milk and dairy foods.
Type 2 diabetes - Studies suggest
that regular consumption of low fat dairy products can help to reduce the risk
of type 2 diabetes, which has been a longstanding problem in adults, and is
becoming increasingly common in children and adolescents. A recent study of
more than 37,000 middle aged women found that those with the highest intakes of
dairy had a reduced risk of type 2 diabetes. The strongest association was
found with low fat dairy products.
Similarly a study of men in 2005
found a reduced risk of type 2 diabetes with increased consumption of low fat
dairy, interestingly, every extra portion of dairy consumed was associated with
increasingly lower risk.
It is thought that this effect may
be due to the combined effects of many beneficial nutrients found within dairy
foods including calcium and magnesium, or the fact that dairy foods have a low
glycaemic index, which helps to control blood sugar levels.
Cancer - There is considerable
evidence to suggest that milk has a protective effect on risk of both
colorectal and breast cancer with increased intakes. A recent study of 45,000
Swedish men reported that men who drank 1.5 glasses of milk per day or more,
had 35% lower risk of the disease than those who had a low milk intake of less
than 2 glasses per week.
Additionally a study of over
40,000 Norwegian women found that those who drank milk as children and
continued to do so as adults, had a lower risk of developing breast cancer. Calcium
and a naturally occurring fat in dairy products known as Conjugated Linoleic
Acid (CLA) have been suggested as protective components in colon cancer.
Hydration - In order to remain
adequately hydrated, it is recommended that we consume 6-8 cups of fluid each
day. If we become dehydrated, it can result in poor concentration and memory
function and leave you feeling irritable and unwell. Milk is an excellent
choice of fluid as it not only re-hydrates the body, but provides a host of
beneficial nutrients and protects the teeth at the same time! Re-hydration
after exercise is particularly important to replace lost fluids, and a recent
study in the USA found that chocolate milk helped the body to recover after
exhausting exercise!
