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INTRODUCTION
The American economic system has enabled the
United States farmer and workman to become the most productive in the
world, giving freedom to all Americans along with the highest standard of
living ever known. The cottonseed industry is proud to be a part of this
system.
Converting raw materials from their natural form into
products useful to man is the central purpose of industry. The cottonseed
industry’s unique contribution to the American economy is the ability to
add value to a by-product of cotton production. This is a brief
description of that industry. Cottonseed—a raw agricultural product
which was once largely wasted—is now converted into food for people;
feed for livestock; fertilizer and mulch for plants; fiber for furniture
padding; and cellulose for a wide range of products from explosives to
computer chip boards.
Cotton is indeed nature’s food and fiber plant.
Although lint is the most valuable product from a field of cotton, it is
very
important to keep in mind that this versatile plant is
also one of our country’s important vegetable oil sources. From this
point of view, cotton is a food crop. How cottonseed oil and the other
products of cottonseed are derived from the raw material is a classic
story of America’s basic agricultural and industrial strength.
COTTON
Early History
Cotton has been grown for its fiber for several
thousand years. Its cultivation and manufacture into cloth developed
independently in both the Eastern and Western Hemispheres. One of the
oldest records of cotton textiles, dating back about 5,000 years, was
found in the Indus River Valley in what is now Pakistan. Excavations in
Peru and Mexico have uncovered cotton cloth identified as being 4,500 to
7,000 years old. Cotton fabrics have also been found in the remains of
some of the ancient civilizations of Egypt and in the ruins of Indian
pueblos of the Southwestern United States, dating back hundreds of years
before Christ. The desire for cotton and cotton fabrics was one of the
factors that led to European explorations during the 15th and 16th
centuries. When he reached the West Indies, Columbus found cotton growing
and the natives wearing cotton cloth. This was part of the evidence that
led him to believe he had reached India. A short time later, Cortez found
cotton production and utilization widespread in Mexico.
Cotton in the United States
Cotton cultivation and use declined in America
following the Spanish conquests, and it was nearly 300 years before the
crop became a major factor in American life. Europeans, who settled what
is now the Southeastern United States, found that cotton was not generally
grown in that area. It is reported that colonists planted cotton in
Florida in the 16th century and in Virginia and the Carolinas during the
17th and 18th centuries. These efforts appear to have had limited success,
and production in the area developed slowly. Varieties of cotton grown in
Central and South America were not suited to the soil and climate of
eastern North America, and time was required to develop acceptable
varieties. In the type that was developed, seed and fiber clung so closely
together that separation was extremely slow and costly. Also, the British
discouraged production of textiles in the colonies since it would compete
with their home textile industry. Under these conditions, tobacco, rice,
and indigo were more profitable crops for the settlers.
The American Revolution brought a marked change. It
lifted many burdensome governmental restrictions from both agriculture and
industry and gave individuals the opportunity to develop to the extent of
their initiative and ability. Two important events in the cotton industry
may be credited, at least in part, to this new freedom. One was in 1790
when Samuel Slater established the first successful textile mill in the
United States at Pawtucket, Rhode Island. The other was in the invention
of the cotton gin by Eli Whitney in 1793 on the General Nathaniel Green
Plantation near Savannah, Georgia. Whitney's gin made possible the rapid
separation of fiber and seed, thereby making it economically feasible to
greatly increase cotton production.
Cotton Production Moves Westward
The 19th century was marked by the steady expansion of
American cotton production, interrupted only by the Civil War. From a
limited area along the Atlantic coast, cotton moved westward to the
Mississippi River and on into the virgin lands of Arkansas, Louisiana, and
Texas. During the twentieth century, it has also become a major crop in
Oklahoma, southern Kansas, southern Missouri, and the western states of
Arizona, California, and New Mexico. In recent years, about eighty percent
of the American cotton crop has been produced west of the Mississippi
River, with about half of the entire U.S. crop being produced in Texas and
California. With eradication of the boll weevil, a devastating cotton
pest, cotton has returned to the southeastern states.
Mechanization Cuts Labor Needs
American cotton production today is almost totally
mechanized. After harvest in the fall, stalks are cut and plowed under the
soil where they rot during the winter. Planting of the new crop begins in
the lower Rio Grande Valley of Texas during February and continues to
spread to the Southeastern states and westward to Arizona and California
as the weather warms. The latest planting is about mid May to early June
in the Texas and Oklahoma High Plains. In the late winter and spring, land
is formed into rows. Mechanical planters are used to seed several rows at
a time. Fertilizer and herbicides may be applied before, during, or after planting. Mechanization has reduced
man-hours required to produce and harvest a 480 pound bale of cotton from
approximately 150 hours in the early 1940's to less than four hours today.
COTTONSEED
History of The Cottonseed Crushing Industry
With each 100 pounds of fiber, the cotton plant
produces approximately 155 pounds of cottonseed. At present production
levels the national average is around 990 pounds of cottonseed produced
per acre of cotton grown. Less than five percent of the seed must be set
aside to plant the following year's crop. The remaining seed is used as
raw material for the cottonseed processing industry or is fed to cattle,
while a small amount is exported.
Although cotton has been grown for its fiber for
several thousand years, the use of cottonseed on a commercial scale is of
relatively recent origin. In ancient times, it is reported that the Hindus
and the Chinese developed crude methods for obtaining oil from cottonseed,
using the principle of the mortar and pestle. They used the oil in lamps
and fed the remainder of the pressed seed to cattle. For many centuries,
however, the use of cottonseed did not develop much beyond that crude
stage and was confined to local areas.
During the first part of the 19th century, plants in
Europe began to crush small quantities of Egyptian cottonseed. These seed
had little or none of the linters (short fibers) that remain on American
upland varieties of seed after the longer cotton lint is removed at
ginning. These fibers, plus the tough hull, made the development of
practical methods for processing American cottonseed a difficult
undertaking.
The first cottonseed oil known to have been produced in
America was exhibited before the American Philosophical Society in 1768.
It was produced experimentally on a very small scale and was generally
regarded as a curiosity. Little effort appears to have been made to
produce additional oil until after the invention of the cotton gin in
1793. The increase in cotton production that followed that invention made
the use of increasing quantities of cottonseed a challenge.
Early Efforts to Crush Cottonseed
During the first half of the 19th century, many efforts
were made to use cottonseed. Several patents on processing machinery were
obtained; a few cottonseed crushing mills were established and newspapers
and magazines contained many glowing predictions of the wealth that could
be obtained from cottonseed. Some of these predictions were premature.
While there are reports of the earlier processing of
small quantities of cottonseed at several points in the South, what is
believed to be the first commercial undertaking to crush cottonseed on a
large scale was the establishment of a mill at Natchez, Mississippi in
1834. Several other mills--at Raleigh, North Carolina; Florence, Georgia;
and Mobile, Alabama--were established about the same time. All of these
failed.
Failure of these early mills was due to several
factors. As noted above, seed of the principal varieties of American
cotton are covered with short fibers or fuzz known as linters. These
fibers are not removed at the gin. Early attempts to use American
cottonseed involved crushing the whole seed without removing the linters
and hulls. Much of the oil was taken up by the very absorbent linters and
hulls resulting in low oil production and an oily feed residue.
Despite these problems and the failure of the early
mills, a number of individuals continued to risk their capital in an
effort to use cottonseed commercially. New mills were built; the 1860
Census reported seven in operation. Three of these were at New Orleans.
Others were at Memphis, Tennessee; St. Louis, Missouri; New York, New
York; and Providence, Rhode Island. Each mill was located so seed could be
delivered by water to take advantage of economical transportation.
Growth of The Cottonseed Crushing Industry
Growth of the new industry ceased entirely from 1861
through 1865 while the nation was at war. In fact, only three mills
survived the conflict. In 1857, just before the Civil War, machinery was
developed by William Fee of Cincinnati that effectively removed linters
and hulls from seed kernels. This equipment--though considerably below
today's standards--overcame the major technical problems that had faced
the early mills, and it made the processing of cottonseed economically
feasible. A significant expansion followed.
The 1870 Census reported 26 cottonseed crushing mills
in operation. This number increased to 45 in 1880 and to 119 in 1890. The
number of mills in the U.S. rose to a peak of about 900 just prior to
World War I. Since that time there has been a steady consolidation. At the
present time there are less than 30 mills in operation. This reduction in
number of plants, similar to that which has occurred in other agricultural
processing industries, is the result of several factors. With limited
transportation facilities during the early growth of the industry, seed
could not readily be brought to centrally located plants. A large number
of small plants were therefore built close to the seed. Machinery
manufacturers were active in promoting the establishment of mills to sell
their equipment. Also, with cottonseed processing as one of the first
industries in a cotton producing area, every town wanted a gin and an oil
mill and these businesses played an important role in the economic
development of the region.
With the development of good transportation, each mill
sought to extend the area within which it purchased seed from gins. The
industry became highly competitive. Mills that were poorly located or
designed, and those that had inadequate capital or poor management went
out of business. Shifts in cotton producing areas left some mills with
insufficient supplies of seed. This also contributed to a reduction in the
number of operating plants. While the number of oil mills has greatly
declined, the volume of seed crushed per mill has significantly increased.
Value of Cottonseed
Until the crushing industry developed, cottonseed had
no cash value except the small sums that might be obtained from the sale
of planting seed. Small quantities of seed were used for fertilizer, and
some were fed to livestock. Most seed were left at the gins for gin
operators to dispose of as best they could. Disposal was a serious problem
that led some states to pass laws prohibiting gins from accumulating large
quantities on their premises or from dumping seed into streams. Cottonseed
was an unwanted commodity whose potential could not be realized.
As mills began operation, cottonseed acquired a cash
value. This was small at first--$5.00 per ton was reported in 1860. This
price was paid only at a few Mississippi River points from which seed
could be readily transported to the mills then operating. It was many
years before farmers in all parts of the Cotton Belt could sell their seed
for cash. In fact, it was not until the turn of the century (1899) that
more than half the cottonseed crop was crushed.
As markets were developed for cottonseed products and
the number of mills increased, the quantity and value of seed crushed rose
substantially. Cottonseed became one of the leading sources of cash income
on Cotton Belt farms. During recent years, the farm value of cottonseed
has averaged about 15 percent of the total farm value of the cotton crop.
Harvesting Cottonseed
Cotton harvesting begins in South Texas soon after the
4th of July and spreads northward, eastward, and westward as the season
advances. In the northern portions of the Cotton Belt, harvesting usually
begins by mid October. Completion of harvest varies from about December 1
in areas east of Central Texas-Oklahoma to as late as mid January in areas
west of there. The harvest period has become much shorter than it was in
the days of hand picking the crop. As mechanical harvesting replaced hand
picking, the beginning of harvest could be delayed since machines are more
effective when at least 75 percent of the bolls are open at first picking
by spindle type harvesters. Spindle harvesters have many horizontal,
barbed, rotating spindles which pick cotton out of the bolls. For stripper
harvesters, all bolls should be open at first picking since stripper
harvesters have rotating brushes or steel rollers which clean the plant of
small stems, leaves, burrs, seed, and cotton. Freshly picked cotton that
has not been ginned is called seed cotton.
From Field to the Gin
Cotton bolls are made up of 4 to 5 locks. Each lock
contains approximately 7 seeds to which the lint is tightly attached. When
fully mature these bolls dry out and fluff open to give the characteristic
look of a field of white cotton ready to pick. According to United States
Department of Agriculture., it takes about 1470 pounds of freshly picked
seed cotton from spindle pickers to produce a 480 pound bale of lint, 740
pounds of seed and 210 pounds of gin trash. It takes about 2350 pounds of
seed cotton from stripper harvesters to produce the same amount of lint
and seed since strippers gather more stems, leaves, burrs, etc. than
spindle pickers. At harvest, most seed cotton is compressed into large
free standing modules where it is stored at the side of the field or on
the gin yard to await ginning. This system improves the efficiency of
harvesters and gins. Harvesters can operate full-time when the weather is
suitable without having to wait for trailers to be returned from the gin,
and the ginning season can be spread over a longer period. The farmer
transports seed cotton to the gin on trailers or module haulers where it
is separated from trash and the lint is removed from seed. There are about
1,500 gins in the cotton growing areas of the United States.
Cottonseed are bulky and, under certain conditions, can
deteriorate rapidly. For these reasons the storage of large quantities of
seed must be done in facilities which are equipped for maintaining quality
by keeping the seed cool and dry.
Grading Cottonseed
Seed may be bought by cotton oil mills from gins either
on a grade basis or "as is." In the former case, a sample is
taken from each shipment of seed as it reaches the mill. A sample is sent
to an independent, government certified laboratory where it is analyzed
and the grade reported to the mill. Grades are based on the quantity and
quality of products which analysis shows can be obtained from the seed.
Cottonseed that contain a designated quantity of products of a specified
quality are classed as "basis" and graded 100. In buying seed on
grade, the mill offers a base price for 100 grade seed. Premiums are paid
for seed grading above 100 and discounts charged for seed grading below
100.
When seed are bought "as is," the price is
based upon average quality, rather than the quality of each individual
lot. A uniform price is paid for all seed delivered to the mill at any
particular time. Seed are regularly sampled and analyzed by the mills
and/or independent laboratories (and sometimes by the seed sellers) so
that they are currently informed of changes in average quality.
The publishing of seed grade standards and trading
rules that serve as the basis for commerce in cottonseed and cottonseed
products is one of the key functions of the National Cottonseed Products
Association. As well as publishing trading rules for seed to be crushed,
the Association has also published rules for feed grade cottonseed which
can be applied to seed being used in the dairy feed industry.
Determining the Value of Cottonseed
Cottonseed prices are quoted in dollars per ton. A mill
determines the price it will offer for seed by first computing the total
value of the products (oil, meal, linters, and hulls) it can obtain from a
ton of seed. From this total value, it subtracts its costs, including such
items as wages and salaries of employees, fuel and power, repair and
replacement of machinery and buildings, freight, supplies, interest,
insurance and taxes to Federal, state and local governments. It will also
subtract an amount for profit it hopes to earn on capital investment. What
remains is, in theory, the price the mill will offer for a ton of seed. In
practice, however, competition among mills and other handlers for
available seed frequently forces them to pay prices above such a
theoretical level.
Regardless of theory or paper calculations, in the
market a mill must meet its competitors' prices or it will not be able to
buy seed. The competitive market for cottonseed benefits farmers and
consumers alike. It establishes top price for cottonseed and lowest cost
for consumer products.
Year-round Processing
Like most industries that process agricultural
commodities, the operations of the cottonseed industry are somewhat
seasonal. Nearly one-third of the year's supply of seed reaches the
crushing mills within one month during peak harvest time. From September
through December mills receive 83 percent of the year's supply of seed; by
the end of January 94 percent of the year's crop is in storage. With
mechanical harvesting and with the extensive use of high speed, large
volume gins, seed moves to the mills much more rapidly than it did just a
few years ago. Because of this rapid movement and the fact that the high
moisture level in recently picked cottonseed makes it a perishable
commodity, most mills operate 24 hours a day. Round-the-clock operation
makes it possible to process most seed which contain high moisture before
it deteriorates; it also reduces the amount of seed storage capacity that
mills must maintain and enables them to meet peak demand for feed
products.
About 40 percent of the year's seed is processed during
the four months of October, November, December, and January. In contrast
to the shortened period of seed receipts, the crushing period has
lengthened in recent years as a smaller number of mills process larger
quantities of seed per mill. Most processors now operate year-round.
To use their capital and labor more effectively, some
mills engage in activities other than cottonseed processing. Where
supplies are available, these mills process other oilseeds, such as
peanuts, sunflower and safflower. Other supplements to cottonseed
processing include the manufacture of fertilizer and mixed feeds, the
distribution of planting seed, feed, and farm supplies and the storage of
grain.
Delivering Cottonseed to the Mill
Most cottonseed reach the crushing mills by truck.
Three methods of unloading--gravity flow, truck dumper, and pneumatic
unloader--are used. A pneumatic unloader uses air suction to draw seed
from the truck and transfer it to conveyors which move it to storage. When
gravity flow is used, a specially designed truck is usually parked over a
large pit that is covered with heavy steel grates. The sideboards of the
truck are removed and the seed falls into a pit where conveyors move them
to storage. This method of handling cottonseed is popular in the West.
The truck dump raises the front end of the truck,
causing the seed to slide out into a pit. While involving somewhat higher
original cost than the other two methods of unloading, the truck dump
requires less labor and can unload seed more quickly.
As seed are received at the mill, samples are taken and
analyzed, especially for moisture and free fatty acid content, which are
indicative of storage life and oil quality. On the basis of such analyses,
seed are placed in storage in accordance with their keeping quality. Seed
that are most likely to spoil are processed first. Seed storage houses at
the mills are equipped with large fans and a series of air ducts which
draw air downward through the seed to keep them cool and prevent spoilage.
Storage and Handling
Cottonseed for Feeding
Cottonseed that is to be used for dairy cattle feeding
is handled and stored just like seed destined to be crushed. This is
important because cottonseed can deteriorate rapidly if not stored at
proper moisture and temperature levels. The huge covered storage
facilities, drying fans, and temperature control equipment present at an
oil mill are ideal for maintaining the quality of cottonseed which must be
fed or crushed many months after it is harvested. Many cottonseed oil
mills market whole seed to dairymen who value the seed for its high
energy, protein, and roughage content. Feeding raw oilseeds, and
especially cottonseed, are one way that dairymen provide concentrated
nutrients, particularly energy, to very high producing dairy cows. Some
oil mills also provide delinted cottonseed for the dairy trade. When
linters are removed (see below) the nutritive value of remaining seed is
slightly improved for the dairy cow and the increase in bulk density and
ease of flowability and handling are advantages in modern dairy feeding
operations.
First Steps in Processing
In the first step of processing, seed are cleaned to
remove any leaves, twigs, pieces of boils or sand picked up in the fields
or in handling. Various combinations of revolving screens, shaker screens,
and pneumatic equipment are used for this purpose. After cleaning, seed
are conveyed to the lint room where the short fibers, known as linters,
are removed. The delinting machines, employing the principle of the cotton
gin, consist of a series of circular saws on a horizontal revolving shaft.
These saws project through a set of steel ribs. As seed fall on the
closely spaced ribs, the saws revolve, cutting off the short fibers. The
linters are removed from the saws by brushes or air and are collected and
pressed into bales. A type of delinting known as abrasive delinting is
used by a few mills. This process uses a physical rubbing action to remove
the linters.
Seed may be run through the delinting machines once, in
which case the linters produced are known as "millrun." Most
mills run the seed through twice and produce "first-cut" and
"second-cut" linters. First cuts consist of the longer, more
resilient fibers; while second cuts are made up of short fibers or fuzz.
The proportion of firstcut and second-cut linters may be varied within
limits. Recently, industry wide production of the three types of linters
has been: first-cut 17 percent, second-cut 70 percent, and mill run 13
percent.
Removing the Hulls
After the linters are removed, seed move to the
hullers. The protective hull which surrounds the cottonseed kernel is
relatively tough. Hulling is accomplished by a machine employing a series
of knives which cut the hulls and thereby loosen them from the kernel.
Seed are then passed through a series of shakers and separators which
separate hulls and kernels. Good separation is necessary for the efficient
production of quality oil and meal. After separation, hulls are ready for
marketing--in bags or in bulk. The kernels, or meats, are now ready for
oil extraction.
Extracting the Oil
In the last 50 years major changes have been made in
methods of removing oil from cottonseed. Up through World War II, this
processing step was usually performed by a hydraulic press. Since that
time rising labor costs have caused the industry to shift to processes
requiring less labor. Today, oil is removed from the seed primarily by
mechanical screw presses, by solvent extraction, or by a combination of
both. For both processes, meats (kernels) pass from the huller through a
series of heavy cast iron rollers arranged one above the other which
revolve at high speed. The rolls reduce meats to thin flakes.
For screw pressing the flakes move from the rolls to a
cooker or conditioner where they are "cooked" and the moisture
reduced to a low level. From the cooker they flow directly into the press
which has a screw or worm revolving inside a horizontal steel barrel. The
screw press operates much like a large meat grinder. Flakes enter one end
of the barrel where they are exposed to very high pressure--as much as 10
to 12 tons per square inch--created by the revolving screw. Oil is forced
from the meats and flows through small openings in the barrel of the press
to a receiving chamber below. From there it is piped through a filter,
which removes fine particles of meats, and on to storage tanks. The
extracted flakes in a ribbon of cake move out the other end of the barrel.
After cooling, they are ground into meal which is sometimes further
processed into pellets. The meal produced by the screw press process has
about 3-4% residual oil remaining.
The newest technology uses an expander which helps
release the oil and prepare the kernels for oil extraction. After the
preparation step, the expanded collets are exposed to an organic solvent
that dissolves out the oil. The mixture of oil and solvent is then put
through a series of evaporators and stills to remove all solvent from the
oil. The solvent is recovered and re-used. Extracted kernels are put
through a desolventizer to remove and recover the last traces of solvent.
They may then be toasted and ground into meal or processed into pellets.
Meal produced by solvent processes usually contains 1-3% residual fat.
Large, efficient processing plants of today employ the expander-solvent
method to produce highest quality products at lowest cost.
Cottonseed processing plants using solvent extraction
can employ a combination of screw pressing followed by solvent extraction
that is known as the "prepress" process. In this operation the
flakes are first put through screw presses under medium pressure. This
step reduces the oil content from 33-35 percent down to 18-20 percent. The
partially defatted residue is then subjected to solvent extraction to
remove the remainder of the oil. Residual oil remaining in meal from this
process is about 1% or less. Since this method is not as efficient as an
expander, it is no longer used in the U.S.
COTTONSEED PRODUCTS
Oil From Cottonseed
In recent years, industry-wide yields of products per
ton of seed have averaged about 320 pounds of oil, 910 pounds of meal, 540
pounds of hulls, and 167 pounds of linters, with manufacturing loss of 63
pounds per ton. These average yields vary from area to area, year to year
and mill to mill, depending upon the character of the seed, the type of
process used, and market conditions. Of the four primary products produced
by cottonseed processing plants, oil is the most valuable. On the average
it accounts for about 40-50 percent of the total value of all four
products. Cottonseed oil is used almost entirely as a food for man.
Fats and oils play a highly important role in the human
diet. Fats are the most concentrated form of energy, supplying over twice
the calories of energy per unit of weight than is provided by proteins or
carbohydrates. Besides furnishing energy, fats are the only sources of
certain essential fatty acids that are not made by the body but are needed
for growth and proper function. They are good carriers of several of the
vitamin groups--A, D, E, and K--and they assist the body in absorbing
certain other vital food elements. In addition to their direct food value,
fats and oils improve the flavor of other foods and thereby contribute to
enjoyment and digestion.
Up until World War II cottonseed oil was the major
vegetable oil produced in the U.S. It now ranks third in volume behind
soybean oil and corn oil.
Food Oil Requires Further Processing
Crude cottonseed oil from the mill requires further
processing before it is used in food. The first step in this process is
refining, which is carried out by warming the oil and adding sodium
hydroxide. This alkali combines with a portion of the oil to form what is
known as soapstock or foots. The soapstock, together with impurities that
may be present, is then separated from the oil by means of a high-speed
centrifuge. (See Guide to Edible Oils for more detail on vegetable oil
refining)
The refining process also removes darker coloring
materials present, leaving a clear yellow oil.
For most purposes cottonseed oil is bleached. This
process involves warming and adding a special bleaching clay. The clay
combines with coloring materials remaining in the oil after refining and
is then separated from the oil by filtration. The degree of bleaching
varies, depending upon the type of finished product in which the oil is to
be used. For use in shortening a very clear oil is preferred. Most
margarine manufacturers also prefer a clear oil so they can more closely
control the color of their finished product. For cooking oil, salad
dressings, snack foods, and similar products the oil may be either clear
or a light golden color.
Refined cottonseed cooking oil turns cloudy at 40-50°F
and becomes solid at a little below 32°F. To control this
characteristic the oil is winterized. This is accomplished by reducing its
temperature to 38-40°. A portion of the oil, known as stearine,
crystallizes or solidifies and is separated from the liquid oil by a
filter process. The stearine is used in shortening and margarine products.
All cottonseed oil, whether winterized or not, is
finally deodorized by exposing it to steam under a partial vacuum to
remove unwanted flavors and to further purify it before use. Refined and
deodorized cottonseed oil is one of the purest food products available.
Few foods can be as highly cleaned and refined as vegetable oils and still
maintain their nutritional quality. In salad oil, mayonnaise, salad
dressing, and similar products cottonseed oil is a favorite because of its
superior flavor stability. This quality has been, to a large degree,
responsible for the increased use of such foods in the American diet.
Flavor stability is also important since considerable time may elapse
between production and consumption of foods, and they may be subject to a
variety of storage conditions during this period.
In addition to flavor stability, cottonseed oil also
has superior nutritive qualities. Cottonseed oil has no cholesterol. Since
cholesterol is only produced by animals, products like butter, lard and
tallow contain cholesterol, but none of the oils from plants contain
cholesterol. All vegetable oils contain fatty acids that can be either
harmful or helpful to our health. Oils high in saturated fatty acids have
been shown to raise blood serum cholesterol levels, which may lead to
heart attacks. Polyunsaturated oils have been shown to reduce serum
cholesterol levels. All the domestically grown vegetable oils, including
cottonseed oil, have one thing in common -they are high in
polyunsaturates, moderate in monounsaturates, and low in saturated fat.
Cottonseed oil has a 3:1 ratio of unsaturated to saturated fatty acids.
This meets the recommendations of many health professionals and allows
cottonseed oil to be used without further processing.
About 70% of the cottonseed oil used in the United
States is consumed as salad or cooking oil. About one-fifth is used in the
production of baking and frying fats, commonly referred to as shortening
and a small amount is consumed in margarine.
Cottonseed salad oil is ideal for use in dressings and
marinades. It enhances vegetable and meat flavors. Many chefs prefer it
for their "house" dressings. Also, cottonseed oil's light
non-oily consistency and high smoke point make it most desirable for
cooking oriental dishes and stir-fry vegetables. In fact many chefs use
cottonseed oil in dishes where oil flavor interference is not desirable.
Sesame, olive and peanut oils can be used to add flavor to a dish.
For use in shortening or margarine, cottonseed oil must
be solidified. This process involves the addition of pure hydrogen to the
oil at an elevated temperature in the presence of an inert catalyst. The
hydrogen combines with the oil which is then pumped through a filter press
to remove the catalyst so it can be cleaned and reused. The oil becomes
solid upon cooling. Careful control enables the processor to vary the
degree of hydrogenation to obtain the melting point and consistency
desired in the finished product. After hydrogenation the oil is deodorized
to improve freshness and extend shelf life.
Oil to be used in shortening is put through a finishing
process that involves chilling and aeration under pressure. Certain minor
ingredients may be added to improve creaming or other specific qualities.
The finished products are then packaged in cans, jars, cartons, or drums.
Very high melting point products such as "flakes" can be
packaged in bags. This product is used as an ingredient in shortenings,
cake icings, and other products where specific creaming properties are
needed.
For margarine production the oil is hydrogenated, as it
is for shortening, but to a different melting point and consistency. It is
then mixed with cultured pasteurized skim milk in the ratio of about four
parts of oil to one of milk. Salt, vitamins, color, and some minor
ingredients are added. The mixture is then thoroughly blended and chilled
under pressure. The result is a wholesome, nutritious, cholesterol free
tablespread that is similar to butter but substantially lower in price.
Non-Food Uses for Cottonseed Oil
While most cottonseed oil is used for food, limited
quantities enter the production of inedible products. Usually, these
consist of off-grade oil or of the soapstock that is a by-product of the
refining process. Both crude oil and soapstock are used to produce fatty
acids which in turn enter livestock feed and a wide range of industrial
products such as soaps, emulsifiers, pharmaceuticals, insecticides,
fungicides, cosmetics, rubber, plastics, and finishes for leather, paper,
and textiles. With advances in science and technology, such uses may be
expected to expand. The use of cottonseed oil for agricultural pesticide
applications instead of water or petroleum based oils has created a modest
new market for cottonseed oil. This has been partially the result of
improvements in spray nozzle design. Low volume and ultra low volume spray
technology involves the uniform application of only a few pints of
pesticide over an entire acre of land. The oil helps the chemical adhere
to the target. This allows for less total use of chemicals and thereby
reduces environmental concerns regarding pesticide applications. Another
use of the crude oil is as an insect attractant in specialty insect baits
such as mole cricket bait.
Since cottonseed oil is an edible product it is ideal
for use in dust control applications in the food, feed and bedding
industries.
Cottonseed Meal
Cottonseed meal is the second most valuable product of
cottonseed, usually accounting for over one-third of total product value.
It may be sold in the form of meal, cake, flakes, or pellets. Cottonseed
meal is used principally as feed for livestock and is usually sold at a
41% protein level. Its major value is as a protein concentrate. One of the
essentials of a ration is good quality protein which is necessary to build
muscles, nerves, blood, internal organs, hair, and skin. Meat, milk, and
wool--the major products of the livestock industry--are all rich in
protein.
Most farm grains and roughages are deficient in the
protein necessary for animal maintenance, growth and development.
Cottonseed meal, a leading protein supplement, provides the protein
necessary to overcome this deficiency and also conserves available
supplies of grain and roughages. It furnishes three to six times the
protein of most grains and 10 to 20 times that of the lower quality
roughages. When used only in the amount necessary to balance a ration, one
pound of meal will save two and a half to three pounds of grain. In
addition to its high protein content and high energy value, cottonseed
meal is higher in phosphorous than any of the other vegetable proteins.
Cottonseed meal may be used to some extent in the
rations of all classes of livestock. It is sufficient as a sole source of
protein for mature ruminants such as beef cattle and sheep and can provide
much of the protein for dairy cows. Since it is a natural protein source
its nitrogen is effectively utilized and there is little danger of excess
ammonia being produced in the rumen or stomach of these cud-chewing
animals as sometimes occurs when feeding synthetic protein materials. High
quality cottonseed meal, used correctly as an ingredient of properly
formulated swine and poultry rations, improves economy and efficiency.
Cottonseed meal usage depends on conditions under which
livestock are being fed. On the farm and in the feedlot, meal may be mixed
with grains, roughages, and other feed ingredients that are available. For
cattle or sheep on the range or on pasture, meal is commonly fed in
pelleted form as the only supplement to grass. Where forage is inadequate,
a meal and roughage mixture is often fed as a supplement. Most swine and
poultry rations used today are complete, manufactured feeds. Cottonseed
meal is used by many feed manufacturers as one of the sources of protein
in such feeds. The National Cottonseed Products Association maintains an
extensive file on current knowledge of feeding cottonseed meal to all
classes of livestock.
Research has been done to determine the potential for
cottonseed protein in industrial markets where proteins are used in
coatings, sizings, adhesives, emulsifiers, and water-based putties and
paints.
A limited quantity of cottonseed meal is used directly
as fertilizer--either alone or in mixtures with other ingredients.
Cottonseed meal is an excellent organic source of nitrogen, phosphorus,
potash, and many minor plant food elements. Its nutrients are released
slowly which prevents waste and ensures long-lasting growth and beauty.
Its organic matter improves soil texture and reduces watering costs. It is
safe to use in liberal amounts without danger of burning and improves soil
acidity required by many plants. Cottonseed meal is especially favored for
use on lawns, flower beds, and gardens. It is also used in the growth
media recipes of many commercial mushroom producers. (See Beautiful
Gardens with Cottonseed Meal)
Cottonseed Hulls
Cottonseed hulls are used primarily as feed for
livestock. Hulls differ from meal, however, in that they are a roughage
rather than a protein supplement. In feeding value, hulls are comparable
to good quality grass hay and can serve as a practical supplement to
pastures. Hulls are easy to store and handle, require no grinding, and can
be fed with less waste than hay. They are an excellent carrier for
cottonseed meal and grain. In feedlots, especially when used with
high-concentrate rations, they effectively prevent digestive disturbances.
Some cottonseed processing mills market a mixture of meal and hulls as an
excellent winter cattle feed supplement. It is usually referred to as
80:20 hull meal mix (80% hulls, 20% meal). Throughout the cotton producing
area hulls are commonly more economical than alternative roughages. They
are seldom shipped outside that area because their bulk, relative to
value, makes long shipments too costly unless the hulls have been pelleted
to increase the bulk density.
Several industrial uses for cottonseed hulls have been
developed. A plastic, containing hulls as a major ingredient, has been
used in producing several small parts of textile machinery. Hulls are
often incorporated in the mud used in drilling oil wells. They can also be
used in the production of furfural, which is a selective solvent used in
making synthetic rubber, in petroleum refining, and in the manufacture of
certain types of plastics.
Industrial use of raw materials such as hulls requires
a reasonably stable supply at a relatively low cost. The supply of hulls
has varied quite widely with changes in government programs controlling
cotton acreage. Demand for hulls also varies considerably with changes in
the availability of other roughage feeds, resulting in wide price
variations. For this reason industrial use of hulls has not been as great
as the potential indicated by their physical and chemical characteristics.
Cottonseed Linters
Cottonseed linters, the short fibers removed from seed
as the first step in processing, are sometimes referred to as "the
fabulous fuzz." Through mechanical or chemical conversion, they enter
a wider variety of end use products than any of the other products of
cottonseed.
Markets for linters fall into two broad
classes--chemical and non-chemical. At the present time, chemical
applications account for approximately three-fourths of total volume.
Generally, first-cut linters--fibers removed the first time seed are run
through the delinting machinery--are longer and find non-chemical uses.
Second-cut linters, those removed in subsequent delinting passes usually
enter chemical products. Mill-run linters, the one-pass "run of the
mill fiber", move into both markets.
Limited quantities of the highest grades of first-cut
linters are used in manufacturing absorbent cotton, medical pads, gauze,
twine, wicks, and carpet yarns. A much greater quantity is put through a
process known as "garnetting" to produce felts or batting for
use in mattresses, other bedding products, and in cushioning for furniture
and automobiles.
As batting leaves the garnetting machine it is sprayed
with a compound which greatly improves its resilience, cohesion, and
stability; it also reduces flammability and dusting. This product, called
"cotton flote", is a highly desirable cushioning material due to
its absorbency and breathability properties and resulting comfort.
Linters are composed principally of pure cellulose and
are, therefore, an important raw material to the chemical industry.
Linters are purified in a chemical treatment consisting of digesting,
bleaching, washing, and drying. The resulting linter pulp may be bulk
baled or formed into large continuous sheets. Sheets can be wound into
rolls or cut and packaged flat in bales for shipment.
Today's health and calorie-conscious consumer is
seeking a wide variety of low calorie, high fiber food products and a
recently developed linter product is meeting that need. Increasing dietary
fiber is now recommended by many health professionals. Edible grades of
cottonseed linter fiber contain more than 99% total fiber. The product is
a pure white, flavorless, odorless flour that is chemically stable so it
will not react with other ingredients to form objectionable flavors,
colors or odors in foods. It is used in many food products including baked
goods, dressings, snacks and processed meats. Linter fiber is also used to
improve the viscosity of dressings and is commonly used to bind solids in
pharmaceutical preparations such as tablets. It helps retain moisture and
extends the shelf life of baked goods. Since linter fiber is white and is
one of the purest forms of fiber, it has obvious advantages over other
sources of edible fiber such as wood pulp.
Linter pulp has many other applications. One of the
earliest uses was in making smokeless gun powder. Still today, selected
small arms ammunition, air-to-air and air-to-ground rocket propellants,
and large solid-fuel rockets utilize nitrocellulose derived from cotton
linter pulp.
A large quantity of linter pulp is also used in
photographic film and in the production of molding plastics and lacquers.
Plastics are used in many molded products such as instrument panels,
steering wheels, radio cases, signs, toys, flexible pipe, and handles for
toothbrushes and tools. A substantial volume of linter pulp is also used
in the manufacture of high grade bond paper. Cotton rags and clippings
were traditionally used for this purpose, but many of the rags and
clippings generated today contain synthetic, thermo-plastic fibers not
suitable for paper making. Therefore, manufacturers are turning
increasingly to linter pulps to obtain the strength and fold resistance
they desire in fine high cotton content papers.
Linter pulp is also used in the production of such
diverse items as sausage casings, cellulose lacquers for use on furniture,
metal, and in fingernail polishes, decorative laminates, industrial and
automotive filters, battery separators, and printed electrical circuit
boards for use in the computer and electronics industry.
Linter pulp is higher in price than competing products,
but in each of the markets it serves, it is preferred on the basis of
superior quality and performance.
COMPETITIVE MARKET
Cottonseed products enter markets that are highly
competitive. Domestically, soybean oil, corn oil, peanut oil, sunflower,
and safflower, and some of the animal fats are competitors of cottonseed
oil. Since the United States is a substantial exporter of fats and oils,
cottonseed oil must compete with coconut oil from Southeast Asia, palm oil
from Malaysia, African peanut oil, olive oil from the Mediterranean basin,
European sunflower oil and Canadian Canola oil as well as other
commodities of the same type. When made into shortening or margarine,
cottonseed oil competes with lard and butter. The prices of all these
commodities are closely related and one of them usually does not get far
out of line with the price of the others. Buyers of fats and oils usually
can shift to a less costly substitute quite easily.
Cottonseed meal encounters a similar degree of
competition from other protein concentrates like peanut meal and sunflower
meal but especially soybean meal. Synthetic sources of nitrogen, such as
urea and the ammoniated feeds, are also of competitive importance.
Cottonseed meal is normally used as a supplement to feed-grains. However,
if meal becomes high-priced relative to grains, feeders will increase
grain use and reduce meal.
Cottonseed hulls meet competition from various types of
hay and from such feeds as corn and sorghum silage. Since hulls are bulky,
it is frequently not economical to transport them great distances for feed
purposes. Therefore, the market is restricted geographically, and the
value of hulls is determined largely by the supply and demand for hay and
other roughages produced in the area.
Like the other cottonseed products, linters meet a
great many competitors in their struggle for markets. Cotton waste, a
by-product of the textile industry, is linters' major competitor in the
bedding, automotive, and furniture industries. Foam rubber and
polyurethane foam also compete for these markets. Wood pulp is the
principal competitor of linters in the chemical products market. While
inter pulp is preferred for quality, wood pulp quality has been improving,
sells at a lower price and has been able to increase its share of the
chemical market.
Competition which cottonseed products meet in the
market place is a central feature of American business. Under that system,
which has proved far superior to any other, each product must stand on its
merits or yield to competitors that serve the consumer more effectively or
at lower cost. It is in this type of business environment that cottonseed
processors use ingenuity, technology, and management skills to keep all of
their many products competitive.
The National Cottonseed Products Association (NCPA) is
the national organization of firms and individuals engaged in the
processing of cottonseed and the marketing of cottonseed products. Among
its major services are:
- Serves as a medium for the exchange of information on mutual
problems and for unified effort on industry wide opportunities.
Publishes uniform trading rules covering product standards and
trading procedures, with arbitration facilities to settle disputes.
Provides members with information on legislation, administrative
rulings, federal regulations, court decisions, and market developments
affecting their business.
Encourages the use of cottonseed products.
Provides the public with information on cottonseed, cottonseed
products, and the processing industry.
ACKNOWLEDGEMENT
We appreciate those who have helped obtain photographs and edit the
manuscript for this booklet. This publication is the result of a team
effort. Contributors to this project are listed in the printed ninth
edition of this brochure.
CSIP 10th Edition
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