棉籽深加工技术新进展

在简要介绍国内外各种棉籽饼粕脱毒方法的基础上,概述了利用棉籽油等植物油脂制备生物柴油以及直接利用棉籽为原料制备生物柴油的技术,并对基于双液相萃取技术处理棉籽、联产无毒粗蛋白和生物柴油的新工艺进行了评述.     

The processing and storage characteristics of glandless cottonseed

Two consecutive storage tests of seven and six-months' duration were conducted to determine the relative effects of adverse storage conditions on glandless and glanded cottonseed and the products derived from each. The moisture conditions during storage resulted in extreme quality deterioration in both glandless and glanded seed. The damage sustained by glandless seed was not substantially different from damage occurring to glanded seed. Neither did glandless seed appear to deteriorate at a faster rate. Normal direct solvent extraction processing methods were followed to process seed for products quality evaluations as measured by nitrogen solubility, epsilon amino free lysine, and gossypol content for meals and FFA, cup refining loss, refined color, bleach color and gossypol content for oils. Oil from glandless seed refined and bleached to lower AOCS colors than corresponding glanded seed oils. Refining losses for oils from damaged seed were slightly higher for glandless seed oils. The meal quality from glandless seed was superior in all categories measured. A laboratory of the Cotton Research Committee of Texas operated by the Texas Engineering Experiment Station.     

Evaluation of cottonseed aflatoxin testing programs

A computer model was developed to simulate cottonseed aflatoxin testing programs. By use of the model, probabilities of obtaining certain aflatoxin test results for various lot concentrations and sample sizes were determined. Also, the effects of sample size and the definition of good and bad sample quality on the probability of lot acceptance were demonstrated. Paper number 5247 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, NC 27607.     

Evaluation of biodiesel obtained from cottonseed oil

Esters from vegetable oils have attracted a great deal of interest as substitutes for petrodiesel to reduce dependence on imported petroleum and provide a fuel with more benign environmental properties. In this work biodiesel was prepared from cottonseed oil by transesterification with methanol, using sodium hydroxide, potassium hydroxide, sodium methoxide and potassium methoxide as catalysts. A series of experiments were conducted in order to evaluate the effects of reaction variables such as methanol/oil molar ratio (3:1–15:1), catalyst concentration (0.25–1.50%), temperature (25–65 °C), and stirring intensity (180–600 rpm) to achieve the maximum yield and quality. The optimized variables of 6:1 methanol/oil molar ratio (mol/mol), 0.75% sodium methoxide concentration (wt.%), 65 °C reaction temperature, 600 rpm agitation speed and 90 min reaction time offered the maximum methyl ester yield (96.9%). The obtained fatty acid methyl esters (FAME) were analyzed by gas chromatography (GC) and ¹H NMR spectroscopy. The fuel properties of cottonseed oil methyl esters (COME), cetane number, kinematic viscosity, oxidative stability, lubricity, cloud point, pour point, cold filter plugging point, flash point, ash content, sulfur content, acid value, copper strip corrosion value, density, higher heating value, methanol content, free and bound glycerol were determined and are discussed in the light of biodiesel standards such as ASTM D6751 and EN 14214.     

Prepress-solvent extraction of cottonseed,processing conditions and characteristics of products

Summary A study has been made of the relation between processing conditions and the chemical characteristics of cottonseed meals and oils produced by prepressing-solvent extraction. Twenty-six complete sets of mill samples of known processing history and representative of the production at 11 mills were used in the investigation. Cooking conditions were the major factor influencing the distribution of the gossypol between the meal and oil. Reduction in free gossypol during cooking was due to binding with meal components while that occurring during prepressing and solvent extraction resulted mainly from removal of gossypol in the prepressed and solvent-extracted oils. Nitrogen solubility data, which have been suggested as a measure of protein damage, indicated that the major change or reduction in nitrogen solubility occurred during cooking. Very little reduction was noted for prepressing or solvent extraction. The reduction in nitrogen solubility during prepressing is much smaller than that previously reported for normal screw-pressing operations. Prepressed oils gave lower refining losses and lower refined and bleached color than did the solvent-extracted oils. Bleach color reversion, after storage of crude oils for 30 days at 100°F., was greater for solvent-extracted than for prepressed oils. A number of meals exhibited the desirable characteristics of low free gossypol content and high nitrogen solubility. Values calculated for chemical indexes of protein quality, as suggested by Lyman and associates (11), indicate that many of the meals should have good protein quality. Presented at the 45th Annual Meeting of the American Oil Chemists' Society, April 11–14, 1954, San Antonio, Tex. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

Evaluation of peanut and cottonseed oils for deep frying

A comparative study of cottonseed and peanut oils for frying of potato chips was undertaken. Industrial scale frying was conducted for 5 days with cottonseed and 5 days with peanut oil and frying oils and chips were sampled twice a day. Frying oils and oils extracted from stored chips were analyzed for ultraviolet absorption (A₂₃₂ and A₂₆₈), peroxide and acid values. Tocopherol and tertiary butylhydroquinone levels were determined by high performance liquid chromatography. Chips stored at room temperature for 12 weeks were organoleptically evaluated. During the first 20 hr frying the A₂₃₂, free acid and peroxide values of cottonseed oil increased rapidly, exceeding that of peanut oil, which increased moderately. For both oils, constant values were attained during the next 80 hr period, followed by moderate increases during the last 23 hr. Peanut frying oil lost 55% of its tocopherols and 54% of its tertiary butylhydroquinone during frying (103 hr), whereas cottonseed frying oil retained these compounds at the original levels. Tocopherols were also better retained in chips fried in cottonseed oil than in peanut oil. The fatty acid patterns of frying oils and oils extracted from chips did not show significant changes due to frying and storage, respectively. These results, therefore, suggest that cottonseed oil is sufficiently stable to be used as a substitute for peanut oil in deep frying.     

Evaluation of occupational dust control technology in cottonseed oil mills

Occupational cotton dust control technology was evaluated in 10 oil mills throughout the cotton belt of the U.S. This evaluation was restricted to mechanical portions of each mill: seed cleaning, delintering, hulling and separating, and linter baling. Based on the process machinery observed in these mills, a 500 ton/day model cottonseed oil mill was designed. The occupational dust control systems for this mill were based on current state-of-the-art technology observed during this project. Further improvements based on readily available air pollution control devices have been incorporated. In order to achieve minimal respirable dust concentrations in the mill, all dust emission points have been enclosed to the maximal extent consistent with efficient plant operations. The various processing areas in the mill were designed with negative pressure dust control systems separate from the general ventilation system. The dust control system includes coarse dust removal by high-efficiency cyclones whose effluent discharges into pulse-jet fabric filter bag-houses operated at an air-to-cloth ratio of 20:1. The emission control system for saw-type delinter systems were divided into small units to reduce the deleterious effects of fires. In order to conserve space, Figures 4, 5, 9, 10, 11, 12, 13, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 29 and 30 are not shown, even though they are referenced in the text. Readers desiring copies of these may obtain them at reproduction costs from the authors.     

Evaluation of cottonseed meals prepared by extraction with acetone-hexane-water mixtures

Eleven cottonseed meals have been prepared by batch extractions of a given lot of cottonseed with various acetone-hexane-water mixtures using several different extraction schedules. These meals, together with eight meals of commercial origin and a commercial soybean meal, have been subjected to chemical evaluation and assayed for protein quality using the growing chick as a test animal. In general the acetone-hexane-water meals were superior to the commercial cottonseed meals for promoting the growth of the chicks and, considering all the meals, a linear correlation was obtained between the logarithm of the weight gains and the available lysine contents of the meals. The free and total gossypol contents of the cottonseed meals appeared to have little or no influence on the growth rates. Presented at the 52nd Annual Meeting of the American Oil Chemists' Society, St. Louis, Missouri, May 1–3, 1961. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Characterization and processing of cottonseed oil obtained by extraction with supercritical carbon dioxide

Extraction of flaked cottonseed with supercritical carbon dioxide at temperatures of 50–80 C and pressures of 8,000–15,000 psi yields an improved crude cottonseed oil compared to those obtained by conventional solvent or expeller processes. Improvements include lighter initial color, less refining loss and lighter refined bleached colors. Crude cottonseed oils obtained by supercritical fluid extraction require less refining lye and show less tendency to undergo color fixation while in storage. Presented at the AOCS annual meeting, Chicago, May 1983.     

Evaluation of the food use potential of sixteen varieties of cottonseed

Sixteen new or experimental varieties of cotton-seed, eight glandless and eitht glanded, were extensively analyzed in this study. Ginned seed from each were studied and then kernel samples and finally oil and flour samples prepared from the kernels. Mean values determined for each attribute measured are presented for each type seed. These data are useful for (a) showing the magnitude of particular desirable properties presently being achieved in varieties of each type seed, (b) showing something of the variation of these properties among varieties within seed types, and (c) comparing glandless and glanded seed types for compositional differences.     

Selective fixation of deleterious phosphatidic and pigment materials in commercial processing to improve quality of cottonseed oil and meal

Summary Plant operating-procedures and laboratory controls were set up to evaluate the quality of meal and oil which could be produced through each stage of commercial, prepress-solvent-extraction processing. By altering conventional, prepress-solvent-processing conditions and by increasing moisture during cooking and adding granular soda ash after cooking meats, cottonseed meal rations can be produced which are comparable in feed efficiency to soybean meal rations and satisfactory for feeding laying hens in amounts up to 10% of the total weight of the ration with no egg-yolk discoloration and crude cottonseed oils with low F.F.A. and light color can be produced which refined to low Lovibond colors and with ferining losses approximating the chromatographic loss when miscella refined within minutes after separation from the source material with the exclusion of air and light. Presented at the 48th Annual Meeting of the American Oil Chemists' Society, New Orelans, La., April 29, 1957.     

The effect of processing conditions on the properties of screw-press cottonseed meal and oil

Summary Processing conditions, particularly cooking procedures, have a marked influence on the chemical properties of screw-pressed meal and oil. Cooking prepared meats at 240–250°F., as in normal mill practice, produced meals with low free gossypol content but at the expense of considerable protein damage. The resultant crude oils showed some color reversion upon storage at 95°F. Dry cooking (7% moisture) at temperatures not exceeding 200°F. gave meals of improved chemical properties, but the crude oils exhibited considerable color reversion on storage. Wet low-temperature cooking (200–210°F.), followed by evaporative cooling, yielded a meal intermediate in quality between that for normal mill practice and dry low-temperature cooking. The crude oils, which corresponded to hydraulic-pressed oil, did not exhibit any appreciable color reversion upon storage at elevated temperatures. The selection of processing conditions, notably cooking, enables wide variations in the distribution of gossypol between meal and oil. The increase in the bleach color of crude oils stored at 95–100°F. was found to be directly related to the initial gossypol content of the crude oils. Presented at 44th Annual Meeting of the American Oil Chemists’ Society, New Orleans, La., May 4–6, 1953. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Service, U. S. Department of Agriculture.     

Application of the antimony trichloride-spectrophotometric method to the determination of gossypol in cottonseed and cottonseed products

Summary A method is described which permits application of the antimony trichloride spectrophotometric method to the determination of gossypol in a variety of cottonseed products. Gossypol is determined by means of the following series of operations: 1. extraction of gossypol from cottonseed or cottonseed products by use of chloroform or aqueous ethanol; 2. isolation of gossypol from the extracts by use of aqueous alkali; and 3. application of the antimony trichloride-spectrophotometric test. Data are presented to show the results obtained by application of this procedure to the determination of gossypol in pigment glands, raw cottonseed meats, cooked cottonseed meats, hydraulic- and screw-pressed meals, solvent-extracted meals, gland-free meals, and oils, both expressed and solvent-extracted. Presented at the 39th Annual meeting of the American Oil Chemists' Society in New Orleans, May 4–6, 1948. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Use of ferric chloride to decolorize cottonseed oil

Cottonseed miscella was treated with FeCl₃ to form an iron-gossypol complex. The treated miscella was then extracted with alkaline water. The supernatant lipid filtered through bleaching clay produced an oil containing virtually no light-absorbing color bodies and a product that compared favorably, colorwise, with commercial oil. So. Utiliz. Res. Dev. Div., ARS, USDA.