The Food Waste Solution That
You Might Not Know You Are Using
Some of the bagged bread options in a local grocery store
Do you buy bagged bread in the grocery store? There are usually several options
including bread made with whole grains or containing several different kinds of
grain. You have probably noticed that such breads stay nice and soft for quite
a while. Some people are even
suspicious about that imagining that the bread might be “loaded with
preservatives.” They are not. If you buy the freshly “baked in the
store” options like baguettes, or get those at a bakery, they are really tasty,
but they rather quickly become stale. They become candidates for making French Toast or maybe
croutons. That kind of short-lived
bread is amajor source of food waste and some have even found creative ways to
collect stale bread from bakeries and turn
it into beer.
Fresh bread from in-store bakery
The bagged bread on the other hand can remain good and
usable for a week or more. If you
don’t get through using the loaf for a long time it might get moldy, but in
general each loaf can keep a family fed with morning toast or lunch sandwiches
for quite a while. That didn’t used to be the case. Back in the 1960s the bread aisle was restocked almost every
day and you could buy “Day Old Bread” at a discount - but it wasn’t very
good.
So what changed?
It’s an interesting story that involves crystals and enzymes. We think of stale bread as being “dried
out,” but that isn’t the real issue. Staling occurs when the starch changes to
a crystalline form in the finished bread. The solution to the food waste
problem of stale bread is a type of enzyme called “amylase” that can modify the
bread’s starches during baking and keep that crystalline structure from forming
after the bread is baked. To unpack that, I’ll go into some background on
enzymes and on starch.
OK, flash back to high school biology class. Do you remember learning about
enzymes? Those are proteins and if
you do the 23andme analysis of your DNA, a good deal of it codes for the
enzymes that make your body function.
These very cool proteins “catalyze” chemical reactions, serving
functions like digesting our food, or turning it into the energy that keeps us
going. There are also enzymes in
our liver that protect of from certain toxins.
Bread is made from mostly wheat grains that contain
starch. Starch is a really big
molecule that is a long and branched chain built from many units of the simple
sugar glucose linked together. The reason that a wheat plant makes starch is so
the germinating seed can use it as a source of energy to start growing a new
wheat plant. About 10,000 years
ago, we humans started growing wheat as a crop and it has been a major source
of our food since then. We get
both energy and protein from eating wheat.
When we eat bread, there is an enzyme in our saliva called
amylase that starts breaking the starch into simple sugars and the process
continues in our digestive system.
There is a similar enzyme in the wheat itself because that seed needs to
be able to tap into the energy stored in the kernel when it starts to grow. The yeast we add to make bread also has
various enzymes including amylase and there are even more enzymes from various
organisms in something like sourdough bread. Bread “rises” because the wheat and yeast amylase enzymes
make some of the starch into simple sugars that the yeast then ferments to grow. In the process the yeast makes carbon
dioxide gas that makes bubbles in the dough that make the bread rise. So in the enjoyment of bread there are
already three different kinds of amylase enzymes involved- from the wheat, from
the yeast and later from ourselves.
But after the bread is baked, the
starch that is still mostly undigested can “re-crystalize” into forms that
make the bread taste “stale” to us.
We think of it as “dry” but that isn’t really the
issue. It’s a texture thing based on those starch crystals. What the baking
industry discovered in 1990 is that they could add a different kind of amylase
enzyme to the dough that would control the starch in baked bread and slow down the
formation of the crystalline structure that makes the bread taste/feel
stale.
So if you look at the ingredient list of the bread in the
store, it could list “enzymes.”
The one that keeps the starch from crystallizing is an amylase. Not only
does that reduce the amount of bread waste generated by stores and in
customer’s homes, it also has dramatically reduced the number of trips that
bread trucks need to make from the bakeries to the stores, thereby reducing the
amount of CO2 released into the atmosphere
Note the Enzymes" in this bread
ingredient label
When we eat the bread, that tiny amount of enzyme is just a
protein that our own digestive enzymes easily break down into the amino acids
that we need as a part of our diet.
So the next time that you pull a loaf of supermarket bread
out of your breadbox and find it still soft and tasty, you can appreciate this
robust, enzyme solution to the food waste issue of stale bread!
(Note: I am writing this article as part of a partnership
with the enzyme producing company, Novozymes. This gives me the time to delve
into the technical details about specific enzymes and then try to explain those
in ways that make sense to as many readers as possible)
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