http://www.wnyc.org/story/why-you-shouldnt-take-your-milks-three-week-shelf-life-for-granted/
Why You Shouldn't Take Your Milk's 3-Week Shelf Life For Granted
Aug 5, 2015 · by
From
Buy a jug of milk in the U.S. and, as long as it's in the fridge, you
shouldn't have to worry about it spoiling for about three weeks.
That's quite a luxury. Because it's not the case in many other parts
of the world where fresh milk has a much shorter shelf life.
Milk is highly perishable — a few hours out of the cow at room
temperature, and bacteria, some of which cause disease, start to
flourish.
In places like Uganda, milk typically lasts just one day. The cow gets
milked, and farmers, most of whom have just a few cows, rush to get
the milk directly to the consumer. If it doesn't arrive in time, it
will probably go to waste.
Why? Because three-quarters of Ugandan dairy producers don't have a
way to pasteurize the milk or keep it cool. The same goes for other
African countries, such as Ethiopia and Zambia.
But short shelf life isn't just a problem in Africa. Fresh milk in
Brazil lasts only three to eight days — depending on the availability
of refrigeration.
Unlike Uganda, fresh milk in Brazil typically undergoes
pasteurization, a heat process that kills off bacteria to make milk
last longer. (Editor's note: As several commenters have noted,
ultra-pasteurized milk in unrefrigerated cartons is another product
available in Brazil and other countries. Its shelf life can be several
months.)
But after it leaves the farm, it is often exposed to heat on its way
to the consumer, which cuts into the shelf life.
So what does the U.S. (and other developed nations) have that these
countries don't? A complex system to keep milk cold, says William
Kisaalita, an engineer at the University of Georgia. It's called the
cold chain, and it's a series of refrigerated tanks, trucks and
storage units that milk — and other foods — travel through from farmer
to distributor to consumer.
"Many people [in Uganda] don't have the means to cool milk," says
Kisaalita, who was born there. "Farmers [who produce milk] make $5 a
day. That's not enough to invest in a fridge, and if they did have
one, there's no electricity ... the cost here is so high for
electricity."
The problem peaks during the rainy season when cows are producing more
milk. During that season, Kisaalita estimates, Ugandan farmers lose up
to half of their milk (and profits) to spoilage.
Indeed, the Food and Agriculture Organization of the United Nations
found that 27 percent of all milk produced in Uganda is poured down
the drain each year. That's equivalent to $23 million worth of
profits.
According to Scott Rankin, a food scientist at the University of
Wisconsin, Madison, limited or nonexistent electricity is one of the
main reasons the cold chain isn't as reliable in many developing
countries. But refrigerators also require a big investment that many
farmers can't afford.
Despite the challenges, people are experimenting with all different
ways to extend the life of milk under these circumstances. For
instance, in Brazil, a company recently doubled the shelf life there —
from seven to 15 days — by applying nanotechnology to plastic milk jug
packaging.
To help Uganda's milk producers, Kisaalita is working on a device to
keep milk cool. The cooler runs on biogas, not electricity, so farmers
simply have to collect cow dung to get the machine working. Kisaalita
is currently testing the system with Ugandan farmers, and if it pans
out, milk could be stored overnight and sold fresh the next day.
Struggling milk producers can also form co-ops to share expenses and
invest in refrigeration and a means to adequately process and
transport milk. This method has been quite successful for small
producers in India; the country is currently considered the world's
largest milk producer.
These efforts won't just save money from going to waste. By making
milk last longer, more people could get their hands on a nutrient-rich
food. Milk contains important nutrients like calcium and magnesium —
especially important in developing countries where many suffer from
malnutrition.
But even with the three-week shelf life in the U.S. — all thanks to a
superb cold chain and pasteurization process — plenty of milk goes to
waste here.
Dairy is one of the top three foods wasted in the U.S., and some 17
billion pounds of milk, or 32 percent of the total supply, is lost a
year, according to 2010 U.S. Department of Agriculture data.
So next time you notice that gallon languishing at the back of the
fridge, think twice about letting it see the end of its shelf life.
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Received on Thu Aug 06 2015 - 21:55:57 EDT