SWEET CORN & ONIONS
click here for step-by-step
photos and instructions for roasting corn
by Jerry Parsons, Ph.D.
Horticulture Specialist, Texas Agricultural Extension Service
in San Antonio
This is the good-eating time of the year! All
of those sinfully good-to-eat items are abundantly available
in a face-slapping-fresh form. Of course, fresh tomatoes have
to occupy the number one position of taste lust but a close
second would have to be corn. Our very thoughts become covetous
as we remember that heap of freshly cooked corn steaming with
flowing rivers of melted butter streaming through the kernels.
Such thoughts beckon our salivary desires and arouse the primitive
instincts which we all possess to enjoy some good old down-home
eating! Such culinary extravaganzas border on being dietary
obscenities of over indulgence which have been banned in certain
parts of our society, i.e.,health spas and Weight Watchers.
All of the don't-be-fat propaganda that media-mind-molders
have to offer cannot persist against the lure of fresh corn.
There are two types of corn available. One
is referred to as field corn which is simply that corn which
is grown to be ultimately harvested in a dried form for use
as an animal feed or to make corn tortillas. This field corn
is sometimes harvested in an immature stage (before kernels
harden) and sold as field corn roasting ears.
Some folks wonder where that term "roasting
ear" originated since most of us boil and eat fresh corn.
The nomenclature of "roasting ears" is a carry-over
from the "good old days" when pioneers cooked ears
of corn by burying them in hot coals. In fact, the dictionary
definition of roast is "to cook over an open fire or
in hot ashes." This is something that you may want to
try, but you don't have to dig a pit in your yard and build
a fire - just use your barbecue grill. Place the corn, shuck
(the leaf-like structures which surround the cob and kernel)
and all, on the grill. If you want to slow cook it, don't
put them directly over the hot coals. Don't worry about burning
the shucks; most people (with the exception of Gerald Ford)
remove the shuck before eating the corn. The fun part is to
try shucking the corn, removing the silks and buttering the
kernels before your hands receive third degree burns from
the sultry ear. If your loved ones think that cooking corn
before removing shucks is barbaric and unsanitary, inquire
how many of these complainers have eaten tamales - they are
cooked in corn shucks too. The second classification of edible
corn available is sweet corn. Sweet corn is different from
field corn. The sweetness of sweet corn is genetically controlled
to be greater than that of field corn types. Some people actually
feel that sweet corn is too sweet but I think that if the
truth were admitted, most of those who prefer field corn rather
than sweet corn prefer the larger-size field corn ear and
the more-for-the-money buy. Field corn also offers an option
to those who need a diet containing extra roughage, i.e.,
the quality of the corn is such that you can eat cob, kernel
and all without noticing a discernable difference! Some people
don't even shuck it!
Almost all the sweet corn varieties developed
since the mid 1930's, when hybrid sweet corn was first introduced,
until the last few years, are of this type. These hybrids
have been called "normal," "standard,"
regular," "ordinary," or "common,"
but we'll call them "sugary." The reason for this
is that they get their sweetness from the sugary (su) gene.
Field corn seed doesn't have this gene and it stores energy
for the germinating embryo by depositing starch in the endosperm.
The starch in field corn is made from sugars, mainly sucrose,
that are manufactured in the leaves as a product of photosynthesis
and translocated to the seed during the grain filling stage.
All types of sweet corn disrupt this process of starch synthesis,
resulting in the accumulation of sugar in the endosperm that
isn't rapidly converted into starch. This is what makes sweet
corn sweet instead of starchy. Sugar molecules are shorter
than starch molecules which are actually long, complex chains
of sugar molecules. These shorter molecules pack more tightly
when corn is dried down and this is what gives sugary seed
its characteristic wrinkled, glassy appearance.
WATER SOLUBLE POLYSACCARIDES (WSP's). Another
unique characteristic of the sugary gene (su) is that it causes
water soluble polysaccharides (WSP's) to be deposited in the
endosperm. These are special molecules that give "sugary"
sweet corns their creamy flavor in addition to the sweetness
they get from the sugars. Without these WSP's, corn tastes
HOMOZYGOUS AND HETEROZYGOUS. To get these effects
from the sugary gene (su), a kernel has to receive the su
gene from both the male and female parents. If a seed gets
the same gene from both parents it is called homozygous; e.g.
su su. A kernel that is homozygous su su is sweet and creamy.
Why does some sweet corn taste better than
other? The answer lies in at what maturity the corn is harvested
and how the corn is stored after harvest. Once an ear of sweet
corn reaches its prime, the sugar in the kernels is converted
rapidly to starch. The rate of this conversion depends upon
temperature--the higher the temperature, the faster the conversion.
Sweet corn is best if harvested during the cool of the morning.
Store non-husked ears in plastic bags in the refrigerator.
Maturity of the corn also has an influence on sweetness. Sweet
corn will be ready to harvest from 20 to 28 days after the
silks first appear. Silks will turn from greenish to brown
and dry when the ear is mature. Maturity of the ear can be
tested by opening the husk, rupturing the kernel and examining
the endosperm. If the endosperm (juice of the kernel) is milky,
the corn is ideal. If the endosperm is doughy, you may have
waited a bit late. However, many people enjoy and prefer "mature"
corn; my grandparents prepared doughy corn by cutting off
the tips of the kernels with a knife which allowed the endosperm
to be easily removed when eating. Such a system also avoids
the corn-between-the-teeth syndrome!
Regardless of the kind of corn you purchase,
one variable which you encounter will be constant--the worm
that eats corn will eat both field corn and sweet corn. We
should all respect the worms which we find adorning the tips
of our corn. They are very special. As we carefully shuck
the ear of corn the worm we discover that has already begun
the corn feast without us is really a champion of the species.
It, along with hundreds of its kind, was deposited on the
corn silks during the dark of the night. The law of the corn
silks--survival of the fittest--prevailed and individuals
began devouring the closest relatives. When all of the silks
stopped shaking, only one remained--the Rambo of worms. To
the victor go the spoils--the mean-machine worm eased down
through the silks and enjoyed a few kernels. Why do people
get so upset when they discover this "hero". The
worm is the guardian of purity, i.e., if the corn was contaminated
the worm would be dead. The worm is the surefire indication
of freshness, i.e., if the corn was old the worm would be
pupated into a moth. Look for the worm! It is a hero! It is
the sign of freshness and purity!===========================
Ever since Pliny, the naturalist, some 1,900
years ago credited the onion with being the remedy for 28
maladies, including evil spirits, no other food has come down
to us with so many miraculous attributes. We may have disproved
a hundred old folk tales about onions, but in view of recent
medical and scientific experiments, perhaps we have been too
Onions and garlic oil has been used for many
remedies. Removing warts is one example. Rub them on the wart
every stinking night. Within a week the warts will dry up,
and within three weeks they will disappear entirely. Maybe!
They will never return. But neither will your friends. Garlic
has been used on boils.
Chewing raw onions will cure a sore throat
and cold. Recent medical experiments have proven that the
mouth is completely sterilized after chewing raw onions three
to eight minutes. Maybe onions can be used for birth control
Not all folklore, medical scientists believe,
can be, nor should be, easily dismissed. After all, malaria-stricken
Peruvians used to nibble on the bark of a certain tree - today,
we obtain quinine from that bark to combat malaria. More than
600 years ago victims of gout ate insignificant little purple
flowers from the fields. Today, we use an extract, colchicine,
from that very flower as a remedy for gout.
To those who are reluctant to place much curative
value in just plain foods, it is well to remember that the
lime isn't in the pharmacopeia, but it is a historical fact
that this tiny fruit stopped and held in check the dreaded
scurvy, the only force that threatened England's mastery of
the sea. If the British had used onions, also rich in vitamin
C, instead of lime, the vegetable would have been equally
effective and famous in checking the disease. In fact, the
onion served as a powerful antiseptic in the Dark Ages when
plague and pestilence threatened to decimate Europe.
During the Great Plague in the 14th century, the graves of
the dead were kept from becoming breeding places by being
sprinkled daily with garlic tips. During the First World War
epidemics of typhus and dysentery in Europe were fought with
garlic. Dr. Albert Schweitzer used garlic against typhus and
Medical scientists have finally come to recognize
the amazing germ killing powers of the onion. Doctors believe
that one of the reasons the Italians are seldom bothered by
digestive diseases such as colitis, is due to their habit
of eating plenty of onions and garlic.
During the last war, Russian experiments proved
that there is sound basis for some of the primitive insistence
on the healing power of the onion. In the American Review
of Soviet Medicine 1944, B. Tokin reported that after 15 years
study of the germ killing properties of 150 plants, onions
and garlic proved fatal to typhus, white staphylococci, and
other bacteria. After exposure to onion vapors for one to
three minutes all protozoa were killed.
To prove that onion vapors do have bactericidal
properties, two other scientists, Toroptsev and Filatova,
of the Tomsk State University in Russia, used the onion on
inflamed and often gangrenous soldiers, cases where the amputation
of arms and legs had occurred. They exposed the wounds to
the fumes of fresh onion paste, renewed at five-minute intervals.
After the first treatment all wounds became red instead of
the poisonous grey of infected flesh. After the second treatment,
purulence ceased and the wounds began to heal.
In the U.S., similar experiments have been
conducted. Dr. Carl C. Lindgren, with the University of Southern
California, confirmed the belief that the onion has healing
powers. His studies involved 16 years of experimentation with
the aromatic vegetable. From garlic, the Superman of the onion
family which differs from the onion only in being more powerful
in its effect, he extracted a substance he called crotonaldehyde
which showed favorable results in killing bacteria.
Food chemists have also found that onions possess
a strong germicide known as acrolein which is important in
preventing tooth decay. A dentist in Poland (Dental Abstracts:
April, 1959) had excellent results with the use of garlic
oil in treating dental root canals. Patients were called back
in 3-18 months, and no changes or occurrences of new symptoms
could be found. Garlic was given credit for possessing antiseptic
qualities that remain active for long periods of time.
The Glasgow Chronicle reports a case in 1953
of a boy who had dropsy. After an operation the water again
gathered. When visitors came to see the boy he indicated a
strong desire to eat onions. A friend immediately procured
some. A short while after eating them his swelling went down
and he began to discharge a great quantity of water. He continued
to eat onions every day and apparently was cured.
In the Medical Record, Praxis, German Pharmaceutical
Magazine and Review of Gastroenterology appear reports of
the beneficial effects of the use of garlic on stomach disorders,
especially in the elderly and those with high blood pressure.
The relief from nausea, vomiting, gas and after-meal discomfort
was sufficiently regular and marked for garlic to merit consideration
as a treatment. Using oil of garlic for three weeks, blood
pressure was lowered considerably in 40 percent of the patients;
and dizziness was cleared up in 80 percent of the cases. Modern
physicians have found and have reported that patients placed
on garlic dosage speak of a feeling of general well-being
and increased vitality after a short time. This possibly may
result from the ability of garlic to reduce blood pressure
as well as to effect dilation of the blood vessels and detoxification
of the entire organism. Patients also reported themselves
freed from apprehensions and neuroses previously felt. Garlic,
the evidence shows, is definitely a blood pressure regulator.
It also favorably influences nervous cardia manifestations,
and good results have been obtained in the menopause.
The entire digestive tract is acted upon favorably
by garlic...it tends to detoxify the entire organism, with
special influence upon the heart, blood vessels and blood
pressure, especially in the aged. This attribute may be responsible
for its successful use on excessive tobacco users in chronic
nicotine poisoning. The good effects of garlic also extend
to the micro-organisms, including intestinal worms.
While no claim is made that onions should be
used as a super germ-killing potion, nevertheless they do
possess great hygienic value. Paris physicians lately have
recommended the onion to relieve and temper the ills of high
living. They have found onions extremely effective in relieving
patients suffering from uric acid or whenever tired kidneys
need help or rest. They were not recommended as any specialized
fare, but only to be used in the daily diet.
Of course, no one should have an orgy of onions.
It is still recommended to call a doctor when ill. But as
a nutritive and protective food, the onion is one of the most
valuable vegetables in our diet. Texans have the opportunity
of enjoying the best onion varieties - - grown in Texas -
- in the world.
Today, there are many varieties of onions grown
commercially. These separate into two large groups, the Grano
and the Granex. Grano varieties have round, spherical bulbs,
while the bulbs of Granex varieties are flattened into more
of an oval shape.
Texas is the largest producer of both of these
types. Most of the Texas onions are yellow onions, although
there are a few red and white onions grown as well. The onions
are planted in the fall and grow during the winter for harvest
in May and June. All South Texas onions are sweet onions,
the most popular of which is the Texas 1015Y. This variety
gets its name from its ideal planting date, the 15th of October
and its yellow (Y) color. It was bred at Texas A&M University.
It tends to grow to much larger sizes than other onions. The
Texas 1015Y is much sweeter, too, and in 1985, the 1015Y won
the Sweet Onion Challenge as the sweetest raw onion in the
nation. Other major varieties grown in Texas are the Y33,
which is a Granex, and the 502, which is a Grano. For a complete
history of the development of sweet onion in Texas and, eventually,
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