The Corn Stalk
Corn
is an American success story. Nearly 8 billion bushels are grown in the
United
States every year. Now 8 billion is an impressive number but, since I
have
no idea what a bushel is, I am not immediately impressed. My helpful
dictionary
says a bushel is really 4 pecks. No help there. A little more
investigation
and a bushel proves to be a box a little more than a foot on a side. So
that’s about 10 billion cubic feet or roughly 864 ears of corn for
every
person in the US. I don’t know about you, but I don’t eat that
much corn. What’s done with it? Some of it is used to feed livestock.
Some of it is turned into whiskey. And, over a billion bushels are used
by
corn refiners to produce corn starch and corn syrup.
A grain of corn is nearly 70% starch in the form of
long strings of molecules
that can be straight like hay or branching like tree limbs. These
strings
are organized in spherical patterns forming starch granules. When
heated
in solution, the starch granules absorb water and eventually gelatinize
into
a paste. Starch gel temperature and character can be selected by
choosing
from among hundreds of strains of corn and further controlled by
manufacturing
steps. Food starches are produced that thicken soups, sauces, pie
fillings
and even yogurts. They help suspend fats and proteins in gravies, salad
dressings
and puddings. Industrial applications include a wide range of glues,
pastes
and coatings. It is said the Egyptians used a starch coating to improve
their
papyrus. Even today, paper and textiles are sized with starch to
improve
strength and appearance. Cornstarch powder is misted between sheets of
paper
during printing to prevent ink smear. And, that very same cornstarch is
patted
on a million baby bottoms every day.
Unfortunately,
the very first step in corn refining is a 2-day soak in hot water laced
with
sulfur dioxide. This is called steeping. Then the kernels are ground
into
a slurry, centrifuged and screened to separate the oil, protein and
starch.
The starch is washed and dried, looks pure and white, but carries
traces
of the original sulfur dioxide. The United Nations Codex Alimentarius
Commission
writes standards for the international food industry. Refined corn
products
are classified as food additives and are covered in a book called the
Food
Chemicals Codex. When I pulled a Codex off the shelf of a local
university
library, it looked and smelled brand new. I must have been its only
visitor
in many years. Codex rules state that a corn starch may contain up to
50
ppm (parts per million) of sulfur dioxide. This is a maximum, so it is
reasonable
that the effective SOx concentration listed in our Oxides of Sulfur
Ingredient
Table is about half that.
Starch strings are built of sugar-like molecules. If
the strings are broken
into smaller pieces by acids or enzymes, the starches become slightly
sweet.
Maltodextrin and polydextrose fall into this category of slightly sweet
starches.
The shorter the strings, the sweeter the starch until you finally get
pure
sugars in the form of glucose syrup, commonly known as corn syrup. If
the
corn syrup is crystallized, you get dextrose. If it is dried, you get
corn
syrup solids. All of these forms of corn syrup have effective sulfur
oxide
concentrations about half that of starch. The sulfur oxide is lowered
as
the processing continues. Corn syrup and dextrose are not quite as
sweet
as the sucrose in cane or beet sugar. This limited the appeal of
refined
corn until 1970 when high fructose corn syrup was born. Since fructose
is
slightly sweeter than sucrose, the cane and the beet had met their
match.
High fructose corn syrup is economically manufactured at 42%, 55% and
90%
fructose and further processing can produce pure crystalline fructose.
High
fructose corn syrup and fructose are so highly refined that much of the
sulfur
dioxide is left behind and the effective concentrations are usually low
enough
to be ignored. As a matter of fact, they are almost as low in sulfur as
cane
and beet sugar.
Corn
starches and syrups are the most common sulfured ingredients in modern
foods.
They are to be found in nearly every packaged product in your
supermarket.
This may be a slight exaggeration, but it sure seems that way when I am
shopping
for clean foods. Why should refined corn products be so popular? They
are
economical, easy to handle and available in a wide range of designer
styles.
Also, America’s corn crop is enormous and refined corn consumes only
a small part. This makes refined corn a stable, reliable product with
plenty
of room to grow. And, the uses of refined corn are seemingly endless.
In
addition to the traditional uses of cornstarch, the slightly sweet
starches
like maltodextrin are used as bulking and texturing agents. This is
extremely
important for the low sugar and fat free products that are currently so
popular.
When you take out sugar and fat, you have to put something back in or
things
just don’t taste and feel right. What better than a slightly sweet and
creamy starch that contributes zero sugar and zero fat to the food
label?
For
more than a year, I ate Smucker’s Light Strawberry Preserves to avoid
the high fructose corn syrup common in most other jams. Well, you just
can’t cheat the Brimstone Demons. Smucker’s Light Preserves
contain maltodextrin and polydextrose to make up for the missing corn
syrup.
Unfortunately, the sulfur in these starches is much worse than the high
fructose
corn syrup I was trying to avoid. The 100% fruit products are no help.
They
use grape juice concentrate instead of sugar or corn syrup. And, grapes
have
their own special sulfite problem. So do the sweeteners used by many
diabetics,
the alcohol sugars like sorbitol, malitol and xylitol. Unfortunately,
sorbitol
and its friends are usually made from good old corn starch just like
corn
syrup. And they have SOx ratings about the same as corn syrup. These
days,
I mostly use honey.
The big break for refined corn came in 1984, when
Coke and Pepsi decided
to switch from sugar to high fructose corn syrup. Cola bottle labels
declare
a mixture of "high fructose corn syrup and/or sugar". But guess what’s
in the bottle? That 1984 decision to switch to corn syrup contributed
to
riots in the Philippines where cane sugar production collapsed. And, it
put
corn refining on a growth curve that can only be matched by Microsoft
and
Google. Take a look at the graph of corn sweetener production from 1950
to
1995. This graph is a reflection of a fundamental shift in American
food
habits. In 1950, the corn syrup share of the US nutritive sweetener
market
was a paltry 10%. By 1995, this share was over 50%, bigger than cane
and
beet sugar combined. And it keeps on growing…like a giant blob of
sweet,
pulsating syrup.