Specific heats of cottonseed and its co-products

Most of the annual crop of cotton is harvested and stored for the entire crushing season until the new crop year begins. It is desirable to have specific heat data of agricultural materials so the engineer can manage the heat transfer problem associated with each crop during storage. Thermal properties of agricultural products, such as cottonseed and its oil mill co-products, are not commonly available. Partially because these materials are bulky and lack uniformity, their thermal properties are difficult to assess precisely. The highly sensitive and large-sample volume differential scanning calorimeter has made the precise determination of specific heat of agricultural material possible. This report describes a procedure used to obtain the specific heat of white cottonseed and its co-products as a function of temperature. The materials tested included cotton fiber, whole cottonseed, linters, hulls, meats, and meal. Specific heat values of these materials ranged from 0.32 to 0.6 cal/g/°C at 30°C and 0.42 to 0.72 cal/g/°C at 90°C. When these materials were dried, the values converged to 0.24 to 0.33 cal/g°C at 30°C.     

Relationships between moisture contents of cottonseed flakes and water in miscellas from extractions with acetone-cyclohexane azeotropes

A method for determining the composition of acetone, hexane and water mixtures was adapted for use with acetone, cyclohexane and water mixtures. Techniques for drying cottonseed flakes to different moisture contents for extraction with acetone-cyclohexane azeotropes were devised. Tests for possible gossypol binding occurring during the drying operation were made. Bench scale extractions yielded data which show the water resulting in miscellas when extracting cottonseed flakes at various moisture levels. It is envisioned that in a commercial process utilizing an acetone-cyclohexane-water mixture to produce cottonseed protein products for food uses, the water in the extracting mixture would be stablized at a level somewhere between the 0 and 3% by wt water levels of the two azeotropes used in these studies. Efforts are currently being devoted to defining the optimum practical water level that could be easily attained in commercial usage. Additional products evaluations will also be made. A laboratory of the Cotton Research Committee of Texas operated by the Texas Engineering Experiment Station.     

Variables affecting the yield of normal oleic acid produced by the catalytic hydrogenation of cottonseed and peanut oils

Summary 1. The effects of the following factors have been investigated in the hydrogenation of cottonseed and peanut oils: temperature, concentration of catalyst, pressure of the hydrogen, degree of agitation, and nature of the nickel catalyst. 2. The formation of stearic acid was found to be repressed and the formation of “iso-oleic” acid simultaneously favored by increasing the temperature, increasing the catalyst concentration, decreasing the pressure, and decreasing the agitation. 3. The nature of the nickel catalyst, as influenced by its method of preparation, may have a large effect on the composition of the hydrogenated product. One of the nickel catalysts investigated formed excessive amounts of iso-oleic acid without being correspondingly selective. 4. In the hydrogenation of cottonseed oil, within a comparatively wide range of conditions, the production of total solid acids with a given catalyst is relatively constant, since the conditions leading to the formation of stearic and iso-oleic acid are mutually exclusive. Extremes in either direction, however, lead to the production of excessive amounts of total solid acids. 5. Peanut oil is a more suitable raw material than cottonseed oil for the production of normal oleic acid, because of its initially greater content of this constituent and its lesser content of linoleic acid. 6. On the assumption that a quantitative separation could be made of the liquid acids from the solid acid fraction (saturated and iso-oleic) of the hydrogenated products, leaving minor amounts of unhydrogenated linoleic acid as an impurity in the separated normal oleic acid, the following maximum yields of “impure normal oleic acid” could be obtained: from cottonseed oil, 56 per cent of oleic acid of 85 per cent purity, 53 per cent of oleic acid of 90 per cent purity, and 48 per cent of oleic acid of 95 per cent purity; and from peanut oil, 70 per cent of oleic acid of 85 per cent purity, 68 per cent of oleic acid of 90 per cent purity, and 66 per cent of oleic acid of 95 per cent purity. Presented before the American Oil Chemists’ Society, Houston, Texas, April 30 to May 1, 1942.     

Gaseous ammonia as a refining agent for cottonseed oils

In this investigation the application of gaseous ammonia to cottonseed oil refining was explored. The ammonia reacted quantitatively with the free fatty acids in the oil; its solubility in coftonseed oil was determined as a function of pressure. In “degumming” it was more efficient in removing phosphatides than other agents. A reduction in refining loss resulted for oils refined with gaseous ammonia as outlined and compared with the standard AOCS cup loss analysis. However, the oil colors were substantially higher even though the ammonia treated oils were re-refined with caustic solution. Results using cottonseed oil-hexane “miscellas” containing less than 70% oil showed low refining losses, but the colors were estremely high. Above 70% oil content the losses were higher, but the colors were lower. The colors never equalled “standard cup” results. This study was sponsored by the Texas Engineering Experiment Station and the Cotton Research Committee of Texas.     

Plant scale comparisons of various refining methods for cottonseed oil

Three different refining processes were commercially compared by processing 15,148 metric tons of cottonseed with free fatty acid content varying between 7.1% and 8.9%. All of the seed was prepressed and solvent extracted in the Sanbra plant at Bauru, Brazil. The Ranchers Miscella refining process operating on seed averaging 8.8% F.F.A. yielded more oil of lighter color per ton of seed processed than either of the other processes compared, even though the average F.F.A. of the seed processed during the Ranchers Miscella Refining test averaged 1.7% higher than the seed used in the Sanbra process and 1.1% higher than the average F.F.A. for the seed used in the Low Loss Refining test. In another comparison, screw pressed oil, Modified Soda Ash refined was compared to Ranchers Miscella refining with seed containing about 0.5% F.F.A. The results showed 42% lower refining loss and a color of 3.5 Red Lovibond units less for Ranchers Miscella refined oil than for Modified Soda Ash refined oil. The average cost of converting crude cottonseed oil to prime bleachable summer yellow oil by the miscella refining process described is 20.8￠ per hundred weight of oil (not including refining loss). These costs include the prorated cost of control laboratory, plant labor and supervision, fuel, power, chemicals, depreciation, taxes and insurance.     

A simplified gas liquid chromatographic determination for vitamin E in vegetable oils

A simple and rapid procedure has been developed for the isolation, concentration, esterification, and gas liquid Chromatographic (GLC) quantitation for the Vitamin E content of vegetable oils. Vitamin E is determined by saponification of the oil, ether extraction of the saponified mixture, drying and evaporation of the extract, followed by closed tube esterification and quantitation of the butyrate ester using a gas Chromatograph equipped with a hydrogen flame ionization detector. This technique eliminates the conventional thin layer Chromatographie isolation of Vitamin E normally used prior to direct or trimethylsilyl (TMS) derivative GLC quantitations. Oils fortified with Vitamin E in the 5 to 40 milligrams per 100 grams range showed recoveries of 93.4 to 98.6%.     

Removal of chlorinated pesticides from crude vegetable oils by simulated commercial processing procedures

Crude soybean and cottonseed oil were processed using simulated commercial processing procedures to determine if oil processing would remove chlorinated pesticide contaminants of either natural or spiked origin. Two crude oil lots were spiked with endrin, DDT, DDE, aldrin, dieldrin, heptachlor and heptachlor epoxide before processing. Representative samples of crude oil and products following each processing step were analyzed for pesticide contamination. Results indicated that alkali-refining or subsequent bleaching did not reduce chlorinated pesticide contamination. Hydrogenation prior to deodorization reduced endrin contamination. Deodorization, with or without hydrogenation, eliminated chlorinated pesticides. The results of this study indicate that normal commercial processing of crude vegetable oils for human consumption effectively removes any chlorinated pesticides which may be present in crude oils. It is hypothesized that chlorinated pesticide removal is achieved by volatilization during deodroization, which is supported by known volatilization characteristics, similarity of behavior in pesticides studied, and absence of the pesticide or its conversion products in the finished oils, or both.     

Cottonseed and the southern regional research laboratory

Since many cotton farmers have borrowed to the limit on the lint portion of their crop, the cash income from the cottonseed is frequently the only money handled. Of vital interest to the cotton farmer and oil miller are efforts to increase the oil content of cottonseed, improve methods of extracting the oil in order to increase yields, and other research designed to improve the products from and raise the value of cottonseed. The commodities selected for initial study in the Southern Regional Research Laboratory are cotton, peanuts and sweetpotatoes, and in addition to research on cottonseed, such as enumerated above, studies will be carried out on cotton cellulose, the whole cotton plant, peanut oil and protein, sweetpotato starch and other products and byproducts of the assigned commodities.     

Color stability of glandless cottonseed oil

The color stability of oil extracted from glandless cottonseed contaminated with various levels of glanded cottonseed was studied. The rate of darkening in bleached color of cottonseed oil during storage was proportional to the original glanded cottonseed or gossypol content in the oil and to time and temperature of storage. Glandless cottonseed with 0–10% glanded seed contamination, as might be expected in commercial production of glandless cotton, yielded oil with equivalent or better color when conventionally refined and bleached after 30 days storage at 25 to 40 C than miscella refined oil from glanded cottonseed. This indicates that new oil mills for extracting glandless cottonseed need not invest in miscella-refining units in order to produce high quality oil.     

Confectionery fats. I. Preparation by interesterification and fractionation of pilot-plant scale

A cocoa butter-like fat has been prepared on a pilot plant scale by the interesterification of hydrogenated cottonseed oil and a triolein product or olive oil followed by fractional crystallization from acetone at two different temperatures. The coproducts—a fraction which consists primarily of trisaturates and is obtained by fractionation at 20 to 28°C., and a fraction which is primarily di- and triunsaturates and is obtained from the low temperature (0°C.) filtrate—are reused in the process. In five of the six pilot plant runs conducted, 100 pounds of 70∶30 or 75∶25 mixtures of the hard fat and liquid oil were used as starting materials. In the sixth run, 140 pounds were used. Yields varied from 25 to 35%. Characteristics of the cocoa butter-like fat products are discussed. Variations in the products were made by changing the ratio of starting materials to 75∶25 and by lowering the first crystallization temperature from about 28° to about 19°C. Operational data obtained show that the process has commerical feasibility. Solvent-to-fat ratio was only 4 to 1. Filtration rates based on production of dry solids were 9 to 44 pounds per hour per square foot of filter area, respectively, for the first and second crystallizations. Although time to attain crystallization temperature was about 4 hours in the pilot plant oeprations, laboratory data indicate that comparable products can be obtained for crystallization times as low as one-half hour. The shorter crystallization time would be more applicable for commercial consideration. The steps in the process are considered conventional in commercial processing.     

Cottonseed extraction with a new solvent system: Isohexane and alcohol mixtures

A solvent system, consisting of isohexane and 5 to 25% alcohol, either ethanol (EtOH) or isopropyl alcohol (IPA), was tested for extracting gossypol and oil from cottonseed. The test results indicate that this new solvent system not only is effective in removing free and total gossypol but also is as efficient as n-hexane when extracting oil. The amino acid analysis of cottonseed meal, produced by the new solvent system, is similar to that produced by commercial n-hexane. Present commercial cottonseed extraction and downstream processing of cottonseed oil refining may need little change to adopt this new solvent system. This new solvent system may lead to a solution to the gossypol problem of cottonseed extraction.     

The reaction of picric acid with epoxides I. A colorimetric method

A colorimetric method has been developed for the analysis of epoxides by reaction with picric acid. Picric acid was found to be the best of several acidic chromophores in its reaction with epoxides. Despite a nonquantitative reaction, the product concentration is proportional to the original concentration, i.e., it follows Beer’s Law. The reaction variables were studied with methyl mono- and diepoxystearates, epoxidized cottonseed oil andVernonia anthelmintica oil. The general applicability of the method was demonstrated by reaction with butyl epoxystearate, styrene oxide, a number of 3-substituted propylene oxides and two commercial epoxy resins. Presented in part at the First World Fat Congress, Hamburg, Germany, in October, 1964, and at the AOCS Meeting in Houston, Texas, April 1965.     

Dietary fat composition and tocopherol requirement: II. Nutritional status of heated and unheated vegetable oils of different ratios of unsaturated fatty acids and vitamin E

In studies conducted on male and female rats and involving evaluation of growth, reproductive and lactation performances and of lipid peroxidation, no evidence could be found for the need for added vitamin E (a-tocopherol) over and above that naturally present as tocopherols in the vegetable oils investigated. These oils are in common usage in industry, i.e., liquid nonhydrogenated cottonseed oil, a lightly hydrogenated cottonseed oil and a hydrogenated soybean oil shortening. The ratio of polyunsaturates to total tocopherol in the test oils varied from 640:1 to 9:1. Even those oils obtained from a commercial frying operation after a steady state had been attained contained sufficient vitamin E to meet dietary requirements. Results of in vitro peroxide hemolysis tests conducted on the red blood cells of the test animals did not correlate well with biological performance.     

A new method of detoxification of cottonseed by means of mixed solvent extraction

For several decades, scientists in the field of vegetable oils tried unsuccessfully to detoxify cottonseed by a practical method. By using 20-30% (by wt) of ethyl alcohol (90% in vol) with commercial hexane as a mixed solvent, we were able to extract effectively both gossypol and oil from cottonseed prepressed cake or flakes. Free gossypol in meal was reduced to ca. 0.013-0.04%; total gossypol was reduced to 0.32-0.55%; residual oil was reduced to ca. 0.5% or less. Any aflatoxin present also can be eliminated by this process. The detoxified cottonseed meal can be used as animal feed. Cottonseed protein can be used to substitute for soy protein. The extracted oil is of better quality than that obtained by the usual hexane extraction method, and gossypol is a valuable byproduct.     

A gas chromatographic method for measuring rancidity in vegetable oils

A simple gas chromatographic procedure was developed for measuring the degree of rancidity in cottonseed oil and other vegetable oils. The procedure employs and internal standard for quantitating the amount ofn-pentane in the oil samples and relates this quantity to organoleptic panel tests. The precision is good, and the results correlate well with panel tests. The procedure is very sensitive to detection and quantitation of oxidative changes in oils. Its use minimizes manipulation of the sample and thus avoids alteration of the rancidification products or the state of oxidation.     

Investigation of methods for determining the refining efficiency of crude oils

Conclusions Various methods for estimating the neutral oil content, or conversely the loss constituents of crude cottonseed oil and soybean oil, have been explored. Of those techniques studied the International Chemical Union chromatographic procedure seemed most appropriate because it was found to be reasonably accurate and most reproducible, was easy and rapid to carry out, and required no special, elaborate, or expensive equipment. The chromatographic method has been successfully applied to a variety of crude cottonseed and soybean oils and to a few vegetable oil residues containing high percentages of loss constituents. The results obtained with this technique would appear to be eminently suitable for evaluating the efficiency of plant refining processes. Indications are that the method might ultimately prove useful for establishing the value of the various lots of crude cottonseed oil and soybean oil which normally change hands in commercial channels. The last-mentioned application will probably have to wait for the development of a suitable companion, semimicro, or chromatographic bleach test and the adoption of an adequate acceptable standard spectrophotometric method for measuring oil color. Presented at annual fall meeting, American Oil Chemists' Society, Chicago, Oct. 31-Nov. 2, 1949     

Dietary fat composition and tocopherol requirement: I. Lack of correlation between nutritional indices and results of in vitro peroxide hemolysis tests

In general, the native tocopherols in polyunsaturated vegetable oils such as cottonseed oil, corn oil and their lightly hydrogenated products include sufficient vitamin E for growth, reproduction, lactation and normal lipid metabolism in the rat. The administration of vitamin E to animals fed diets deficient in essential fatty acids (e.g., a hydrogenated coconut oil or a fat-free diet) does not stimulate growth or reproductive performance per se, although testes development in the male rats is improved and some improvement in lipid metabolism is also noted. Hemolysis of the erythrocytes in vitro by hydrogen peroxide is increased in animals on diets rich (30%) in polyunsaturated vegetable oils or on diets providing no essential fatty acids at all. However, the conditions of the in vitro hemolysis test are not related to those in vivo and the in vitro test is not a measure of erythrocyte fragility. In addition, the in vitro hemolysis test does not necessarily reflect plasma tocopherol levels nor an abnormal nutritional state as a result of subsistence on high linoleate, low tocopherol intake, but rather measures the susceptibility to oxidation of a labile biological substrate and indicates the effective balance between potentially oxidizable lipids (polyunsaturates) in the stroma of the red blood cell and the antioxidant present (tocopherol or vitamin E). The labile lipid substrate may be either of exogenous origin (diet) or may be formed endogenously through tissue synthesis (as a result of an essential fatty acid deficiency). It is concluded that the in vitro hemolysis test may not be a valid indicator of vitamin E nutriture unless it is used in conjunction with other nutritional tests.     

Effect of antioxidants,individually and in combination,on stability of carotene in cottonseed oil

Summary and Conclusions By an accelerated test, l-ascorbyl palmitate, alphatocopherol, hydroquinone, and phospholipids from cottonseed and soybean oil have been evaluated singly and in combinations, for their antioxidant effect on carotene in mineral oil and cottonseed oil solutions. Their effects in retarding the formation of peroxides in the refined cottonseed oil were also determined, and similar studies were made on cottonseed oil after the addition of 1.2 mg. of carotene per gram of oil. In the refined cottonseed oil the formation of peroxides occurred concurrently with the destruction of carotene and was greatly accelerated as the carotene disappeared. In mineral oil solutions, no peroxides were found until after the carotene had become completely decolorized. Although alpha-tocopherol was very effective in stabilizing carotene when added to mineral oil solutions neither the naturally present nor added tocopherol was effective in a more unstable solvent such as refined cottonseed oil. To make the tocopherol effective in such a solvent it is necessary first to stabilize the solvent. When the combination of phospholipid and hydroquinone was added to the refined cottonseed oil, the oil was stabilized and a very marked increase in carotene stability was obtained. While the combinations AH, APH, TAH and TAPH did not stabilize the carotene during the early part of the storage tests, they did become effective after about 20 per cent of the carotene had been destroyed and were as effective as PH and TPH when measured at the 50 per cent point. The reason for this ineffectiveness during the preliminary period of storage is not apparent. This is one of four regional research laboratories operated by the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Consistency of mixtures of cottonseed and Paraguayan palm kernel oils

Summary A palm kernel oil, mbocaya, possessing a relatively high iodine value, approximately 30, is being produced in Paraguay. Production can be expanded. One possible use for the oil is as a component of shortenings. As expected, consistency measurements showed the oil to be unsuited for conversion to shortening of the all-hydrogenated type. Blends with hydrogenated cottonseed oil yielded products having acceptable consistency characteristics. However, for a given consistency, the proportion of hydrogenated cottonseed oil needed was greater than that needed for a comparable blend with cottonseed oil. The difference was attributed to the formation of solid solutions or mixed crystals in the latter blend. A mixture of hydrogenated palm kernel oil and cottonseed oil was prepared and found to possess consistency characteristics better than those of a typical shortening of the all-hydrogenated type. Presented at the 28th Fall Meeting of the American Oil Chemists’ Society, Minneapolis, Minn., Oct. 11–13, 1954. Formerly Chief Chemist, Coindu, Asuncion, Paraguay. Sponsored by Institute of Inter-American Affairs under Point IV program. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

The origin of the marine polyunsaturated fatty acids. Composition of some marine plankton

Summary and Conclusions Shrimp, crabs, the marine diatomNitzschia closterium, Platymonas sp., and the fresh water algaChlorella pyrenoidosa were maintained or cultured in the laboratory. The crustacea were fed low-fat, cottonseed oil, and menhaden oil rations. The fatty acid composition of all groups, as well as that of native phytoplankton and zooplankton catches, were determined as the extinction coeffcients, (E _1% ^1cm. ), at wavelengths of maximum absorption. It was found that both shrimp and crabs lost much of their polyunsaturated acids on the fat-free diet and regained it again by ingestion, as do fish. The shrimp however appeared to synthesize more highly unsaturated acids from cottonseed oil than did other aquatic animals. Phytoplankton do produce a high level of polyunsaturated fatty acids. The importance of the determination of the structure of aquatic plant and animal fatty acids in the problem of the origin of the acids and their mechan ism of synthesis was discussed. Contribution from the Departments of Oceanography and Meteorology and of Biochemistry and Nutrition of the Agricultural and Mechanical College System of Texas, Oceanography and Meteorology Series No. 137; supported in part by Grant No. A-777 from the National Institutes of Health and Grant No. A-020 from the Robert A. Welch Foundation.