Can Food Lose Its Nutritional Value Over Time?
Some foods can lose their nutritional value others cannot, let's
take a look into this further.
You know if the label makes a claim on food value, let's say
they manufacture some nutritious drink product and on that drink
is some nutritional claim then let's say it has a shelf value of
two years then at the end of the shelf life that product still
needs to contain 100% of the vitamin C level.
It doesn't mean that when the product was manufactured it
contained 100% of vitamin C and at the end of the shelf life it
can contain half that level of vitamin C. What that means is
that the manufacturer has to put an overage of that vitamin in
the product because some of the vitamins will deteriorate over a
period of time. Depending on the temperature of the storage of
the product, usually the higher the temperature and the longer
the storage time affects the rate of deterioration.
Vitamin C happens to be one of the most sensitive. The
government does inspections on these products. They will
randomly and routinely visit the food manufacturing companies.
They will take samples and often times it is a surprise. What
the food companies will do and the food scientist would do it
when the product is formulated they will add an overage of
vitamins and minerals but usually it's the vitamins. It protects
the product during the shelf life.
What I am saying is that if they want the product to contain
100% of vitamin C at the end of the shelf life, then they may
have to put in 200% to begin with because they know that 2 years
later it will have lost half of its value.
Then what the food companies will do is have documentation on
other food products that they have manufactured so they can
protect the rate of loss. They can predict the rate of loss on
similar products so that when a nutritional beverage is
formulated they can base the level of any particular nutrient
against historical values for similar foods.
Then that is the starting point and what they will do is enter
the food into something called accelerated storage. That is a
higher level of temperature so they can monitor the level of
loss. They call that storage study. Most food companies will do
that on their own accord but they do that in case there is ever
a government inspection because they want to make sure they are
meeting their label claim.
Companies that manufacture vitamins and minerals do the same
thing. If it is a dry food like a vitamin tablet the rate of
deterioration is usually much slower because it is a dry
environment.
In a dry environment you don't get hydrolysis, which is the
break down of a dry product compared to a liquid. The nutrients
break down much faster in a liquid.
There is a whole host of different studies. When a product is
placed in a storage study like that, not only do they access the
nutritional properties of the food but also they have to know if
the food is stable in other ways.
Like fats can oxidize. If you have ever had a bag of cake flour
on your shelf in your kitchen and two or three years later it is
full of weevils and you smell it and it has an awful smell, it
is usually because the fat that is present in the flour has
oxidized. The fat will break down into pre-fatty acids, which is
not necessarily very good for you.