Kurma – Hi! I was wondering, do you have any opinions about
the pros and cons of pasteurisation and homogenisation of milk?
Craig Archer, Mosman Park, Western Australia
Craig. Pasteurisation, as you know, goes a long way in protecting
humans from any infections and bacteria that might be inadvertently
passed on from milk that has been procured from infected animals
and unwashed udders and containers. Some of these infections include
strep throat, staphylococcal food poisoning, salmonella, tuberculosis,
brucellosis and diphtheria.
Although pasteurisation does protect you against these infections,
it can also lead to a reduction of the nutrients present in the
milk, depending on what method of pasteurisation is used.
For instance, the vitamins B1 and C may be affected by as much
as 10 – 20 percent, and B2, B3, B5, B6 to a lesser extent.
The concentration of vitamin E in the milk can also vary markedly
between raw and pasteurised milk.
Another process that the majority of Australian milk goes through
is homogenisation. This process does nothing to preserve milk at
all, but is merely a physical means of creating a more uniform product.
In homogenisation, the fat globules found in the milk are blasted
through an atomiser to form tiny particles so that the fat is dispersed
evenly throughout the milk, and there is no cream plug lying on
the top of the carton.
The process is called homogenisation because it produces a milk
which does not separate the cream and thus appears to be homogenous.
Remember when the milkman delivered glass bottles, and there was
always a cream layer sitting on the top of the milk which could
be poured off and used as cream, or was easy to shake up into the
rest of the milk? Today, manufacturers claim that the milk looks
better, and is easier to use if it has been homogenised.
Unlike pasteurisation, homogenisation is not required by law, but
was taken up as a standard practice for mainly aesthetic reasons.
It was previously thought that homogenisation in no way altered
the structure of milk, yet researchers now claim, that the homogenisation
process allows the absorption of an enzyme called xanthine oxidase
into the bloodstream. This enzyme, usually present in the cream,
is excreted harmlessly through the bowel when present in unhomogenised
milk, yet when it is absorbed through homogenised milk, some
researchers say it attacks the tissue of our heart and arteries,
encouraging an increase in cholesterol levels.
I hope that sheds some light on the subject.
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