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COTTONSEED AND ITS PRODUCTS



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



    © 2002 National Cottonseed Products Association. All rights reserved.