Total Gossypol Research Articles

Determination of (+)‐, (−)‐, and total gossypol in cottonseed by high‐performance liquid chromatography

AbstractGossypol, a pigment in cottonseed, is a polyphenolic, binaphthyl dialdehyde. Due to steric hindrance between the functional groups of the molecule at the bond connecting the two naphthyl rings, gossypol exists as (+)‐ and (−)‐isomers. Gossypol is physiologically active with the (−)‐isomer appearing to be more active and causing temporary infertility in males. It is thus important to know the amounts of isomers in livestock feeds. A quantitative high‐performance liquid chromatography (HPLC) procedure was developed for the separation of (+)‐ and (−)‐gossypol contained in cottonseed. This method involves derivatization of gossypol with (R)‐(−)‐2‐amino‐1‐propanol followed by HPLC separation employing either a Phenomenex Prodigy (5 µ, ODS‐3, 100 × 3.2 mm) or a MetaChem Inertsil (5 µ, ODS‐3, 100 × 3.0 mm) reversed‐phase column eluted with 80% acetonitrile and 20% 10 mM KH2PO4 adjusted to pH 3.0 with H3PO4 at 1.0 mL/min. The (+)‐ and (−)‐gossypol‐2‐ amino‐1‐propanol complexes eluted at roughly 1.4 and 2.6 min, respectively. It was found that gossypol from Upland (Gossypium hirsutum) seed was rich in the (+)‐enantiomer, with the (+)‐ and (−)‐enantiomers in a ratio of about 65:35, respectively, while gossypol from the seed of a Pima (G. barbadense) cultivar (S‐6) was slightly richer in the (−)‐enantiomer (46.8:53.2).

The potential of soapstock‐derived film: Cottonseed and safflower

AbstractOilseed soapstock is seldom used today for the recovery of fatty acids, but it is often added to oilseed meal. The energy value of oilseed meal is marginally increased by the addition of soapstock. To find alternative uses for oilseed by‐products, cottonseed and safflower soapstock samples from industrial plants were characterized using American Oil Chemists’ Society recommended and modified methods. The characterization included moisture and volatiles, phosphorus and nitrogen, neutral oil, total fatty acid amount and individual fatty acid profile, and total gossypol for cottonseed soapstock samples. The characterization indicated that cottonseed soapstock samples contained a slightly larger amount of neutral oil than safflower. These soapstock samples were frozen to −40°C at 40 mm Hg for more than 8 h, thawed, and the low‐boiling compounds were removed by evaporation under reduced pressure. The freeze‐dried soapstocks were mechanically pulverized in an inert atmosphere until able to pass through a 50‐mesh screen. When these freeze‐dried soapstock particles were rehydrated with deionized water, the formation of a gel phase was observed. Casting of this gel phase onto a substrate and subsequent drying without heating resulted in a thin film, a liposomelike material, with a uniform thickness of about 0.01”. The lamination capability of freeze‐dried oilseed soapstocks by rehydration may be attributed to the formation of multiple bilayer lamellae by phospholipids from the oilseed soapstock. Due to its biodegradable nature, the use of soapstock‐derived film as a composite or by itself as an encapsulating agent is highly attractive. The potential of this liposome‐like material as a chemical carrier is discussed.

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

AbstractA 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.

Effects on performance, tissue integrity, and metabolism of vitamin E supplementation for beef heifers fed a diet that contains gossypol.

We conducted an experiment for 112 d with yearling beef heifers to evaluate the effects of cottonseed meal (CSM) fed with various concentrations of vitamin E on hematological and tissue components. Heifers were assigned randomly to four treatments, with eight heifers per treatment. The treatments consisted of the following dietary supplements: 1) CON, based on soybean meal with 30 IU vitamin E/kg; 2) GOS, based on CSM with 30 IU vitamin E/kg; 3) G+2E, based on CSM with 2,000 IU vitamin E x animal(-1) x d(-1); and 4) G+4E, based on CSM with 4,000 IU vitamin E x animal(-1) x d(-1). Supplements based on CSM provided 4.5 g of free and 50.5 g of total gossypol x animal(-1) x d(-1). The total gossypol present in the supplements was 29.1% of the negative isomer (-) and 70.9% of the positive isomer (+). Blood samples were collected at the start of the experiment and every 2 wk thereafter up to 16 wk. There was a time x treatment interaction (P<.01) for plasma alpha-tocopherol ( alpha-T) concentration; however, feeding gossypol did not decrease plasma alpha-T. Weight gain, retinol palmitate, retinol, beta-carotene (beta-C), hemoglobin, and hematocrit were not affected by treatment. Erythrocyte osmotic fragility (EOF) increased (P<.05) in gossypol-fed animals; however, vitamin E supplementation lowered EOF (P<.05). Heifers fed the supplements GOS, G+2E, and G+4E had greater (P<.01) plasma (-)-, (+)-, and total gossypol than heifers fed CON from Collection 2 to the end of the experiment. There was a treatment effect (P<.05) on vitamin E and gossypol concentrations in different tissues, with no effect (P>.05) for trace minerals (Cu, Zn, Fe, and Se). Vitamin E concentration in tissue increased with increased dietary supplementation of vitamin E. In heart and neck muscle, (-)-gossypol was greater (P<.05) than (+)-gossypol, but the reverse was true for liver. Gossypol decreased in vitro lipid peroxidation of liver homogenate in tissues. Gossypol deposition in tissue was liver > heart > muscle. In summary, gossypol from CSM did not decrease concentrations of antioxidant vitamins, including alpha-T, vitamin A, and beta-C, or have any detrimental effect on performance of beef heifers.

Some analytical characters of cottonseed varieties grown in Turkey

Sixteen cottonseed varieties grown in Turkey were analysed. The average oil content in varieties ranged from 309.7g Kg -1 to 379.5g Kg -1 whereas the range in values of gossypol content for glanded varieties was 7.4-12.8g Kg -1 . One glandless variety contained gossypol as 0.2g Kg -1 . The samples contained 337.2- 466.5g Kg -1 protein. Fatty acid composition of the oils obtained from cottonseed varieties were also determined. Generally total gossypol content of cottonseed varieties were below the limits established by the some nations for human food or animal feed.

Influence de l'humidité, des teneurs en coques et en gossypol total sur la couleur de la farine des amandes de graines de cotonnier

This study is a contribution on the knowledge on the nature of colour problems associated with cottonseed kernel flours in some technological treatments. The influence of total gossypol, shell and moisture content on the colour of experimental flours were measured in terms of Hunter L, a, b parameters. Total gossypol, shell and moisture content were positively correlated to the difference of colour (ΔE). The discolouration of flours by extracting colouring compounds with hydroalcoholic solvents has shown that this action is difficult to be achieved. Intrinsic colouring compounds of flours identified by thin layer chromatography were found to be gossypol and derivatives, flavonoids and phenolic acids.

Response of Lactating Dairy Cows to Mechanically Processed Whole Cottonseed

Twenty-four lactating Holstein cows averaging 142 ± 34 d in milk were used in a replicated 4 × 4 Latin square trial to determine the effect of processed whole cottonseed on milk yield and nutrient digestibility. Fifteen percent of the dry matter content of the experimental diets consisted of whole cottonseed, roasted whole cottonseed, a roasted and pelleted blend of whole cottonseed and soybean meal, or an extruded blend of whole cottonseed and soybeans. Apparent digestibilities of dry matter and neutral detergent fiber were higher, and total fatty acids were lower, for cows fed extruded cottonseed than for cows fed roasted cottonseed. No differences were observed among treatments for dry matter intake, milk yield, protein, lactose, SNF, energy-corrected milk, percentages of milk lactose, or percentages of SNF. Milk fat percentage was greatest for cows fed whole cottonseed and roasted whole cottonseed, intermediate for cows fed roasted and pelleted cottonseed, and lowest for cows fed extruded cottonseed. Yield of milk fat was lowest for cows fed extruded cottonseed. Milk protein percentage was lower for cows fed roasted and pelleted cottonseed than for cows fed roasted whole cottonseed. Cows fed extruded or roasted and pelleted cottonseed gained body weight, but cows fed whole or roasted cottonseed lost body weight. Total gossypol concentrations differed among treatments; the concentrations were greatest for cows fed the roasted cottonseed and lowest for cows fed the extruded cottonseed. Processing of cottonseed appears to alter nutrient digestibility and milk composition.

Caloric Analyses of the Distribution of Energy in Ripened Cotton (Gossypium hirsutum L.)

Caloric analyses of the distribution of energy were carried out for Suregrow 125 and DPL-50 cotton plants 40, 101, and 115 days after emergence and for ripened cotton. For these analyses, plants were harvested, dried, weighed, and subsequently analyzed for protein, crude fat, lignin, cellulose, hemicellulose, nitrogen-free solubles, and total gossypol according to standard AOAC methods. In ripened cotton, approximately twice as much caloric energy was found to be released in the combustion of seed in comparison with lint. About half of the caloric content was constituted in lint and seed, the remainder apportioned to vegetative tissues. With 40-day-old plants, the content of nitrogen-free solubles was high and decreased steadily through the 101st and 115th days after emergence with a concomitant increase in cellulose, hemicellulose, and lignin. Keywords: Caloric analysis; Gossypium hirsutum L.; ripened cotton; energy distribution

Compositional characterization of cottonseed soapstocks

AbstractCottonseed soapstock samples, collected during the 1993–1994 crushing season from oilseed extraction mills throughout the United States Cotton Belt, were analyzed by chemical and chromatographic methods. Volatiles averaged 48.7±10.6% (mean±SD,n=39). On a dry basis, the samples averaged 33.3±7.3% fatty acids, 26.3±6.9% phospholipids, 8.4±6.4% triglycerides, and 7.5±3.0% gossypol. The analytical techniques accounted for 93.3±8.6% of the dry soapstock matter. The AOCS method for total fatty acids in soapstock yielded values in agreement with the chromatographic and phosphorus analyses. In contrast, the AOCS method for neutral oil in soapstock gave values that were significantly higher than those obtained by chromatography. The amount of nonlipid material in the samples correlated with the phosphorus content. Total gossypol and nitrogen levels were also related.

Studies on karkade ( Hibiscus sabdariffa): protease inhibitors, phytate, in vitro protein digestibility and gossypol content

Karkade defatted flour extract had chymotrypsin inhibitor activity almost half that of trypsin (21.8 and 40.5 enzyme inhibitor activity units/mg protein, respectively). The protein isolate had a weak chymotrypsin inhibitor activity compared to that of tryprin (4.9–28.3 enzyme inhibitor activity units/mg protein, respectively). The trypsin inhibitor activity of the protein isolate was 70% of that of the defatted flour extracts. Extraction of trypsin inhibitor by citrate buffer (pH 4.6) gave a higher specific activity of trypsin than by phosphate buffer (pH 7.6), Tris buffer (pH 9.0) or distilled water. Heating the extract in boiling water for 10 min destroyed 66.1% of the trypsin inhibitor activity. Karkade protein isolate had lower free and total gossypol than did the whole seed and defatted flour. The in vitro protein digestibility of karkade defatted flour and protein isolate was lower than that of casein. Phytic acid was higher in karkade defatted flour than in soybean defatted flour.

Seed Gossypol Variation within Gossypium barbadense L. Cotton

Gossypol, a triterpenoid aldehyde found in all species of the genus Gossypium, possesses insecticidal, antimicrobial, antifertility, and antitumor properties. Gossypol content in cotton seed varies among cultivated species and among cultivars within species. This investigation was conducted at the Texas Agricultural Research Center in San Angelo, TX, in 1993 to determine the regional and geographic variability for seed gossypol content and isomer form in G. barbadense L. A set of 57 accessions (collected during 50 yr from 21 countries) representing five regions, and 26 cultivars were analyzed. Species′ variation for gossypol and isomer content exceeded previous reports. Total gossypol content in seed ranged from 3.0 to 34.0 g kg‐1 kernel weight. The more biologically active negative isomer ranged from 249 to 689 g kg‐1 total seed gossypol. Cotton accessions collected west of the Andes mountains in South America displayed the greatest variation in seed gossypol and gossypol isomer contents. Accessions from Central Americaa nd Argentina displayed the least variation. Subsets of accessions, possessing unique levels of seed gossypol or gossypol isomer, were identified within regional groups or cultivars. A low (r = 0.02) phenotypic correlation between gossypol content and isomer ratio suggested that simultaneous selection for the two traits is feasible.

Ethanol extraction of oil, gossypol and aflatoxin from cottonseed

AbstractCommercial processing of cottonseed requires hexane to extract and recover edible oil. Gossypol and aflatoxin are not removed from extracted meals. A bench‐top extraction process with 95% (vol/vol) aqueous ethanol (EtOH) solvent has been developed that extracts all three of the above materials with a much less volatile solvent. In this process, cottonseed is pretreated and extracted with ambient 95% EtOH to remove gossypol and then extracted with hot 95% EtOH to extract oil and aflatoxin. Membranes and adsorption columns are used to purify the various extract streams, so that they can be recycled directly. A representative extracted meal contained a total gossypol content of 0.47% (a 70% reduction) and 3 ppb aflatoxin (a 95% reduction). Residual oil content was approximately 2%. Although the process is technically feasible, it is presently not economical unless a mill has a continual, serious aflatoxin contamination problem. However, if a plant cannot meet the hexane emission standards under the Clean Air Act of 1990, this process could provide a safer solvent that may expand the use and increase the value of cottonseed meal as a feed for nonruminants.

Utilisation du tourteau de coton dans l'alimentation des volailles. II. Effets du gossypol sur les paramètres de la reproduction

Trois expériences mesurent les effets du gossypol, administré par voie alimentaire, sur la reproduction des coqs et de poules adultes de souche ponte ou chair. Le premier essai a porté sur 128 poules et 45 coqs pubères; il ne montre aucun effet de doses alimentaires inférieures ou égales à 400 ppm de gossypol libre sur la consommation alimentaire, la ponte, la production et la motilité du sperme, la fécondité et l'éclosabilité des oeufs incubés. Les deux essais suivants ont servi à tester l'effet d'une concentration alimentaire de 800 ppm de gossypol libre sur respectivement 10 coqs reproducteurs de souche chair âgés de 82 semaines et rationnés et 12 coqs reproducteurs de souche ponte âgés de 29 semaines nourris ad libitum. A cette dose (environ 20 mgkg PV/j) le glossypol libre a diminué la consommation alimentaire, le poids des animaux et des testicules des coqs de souche ponte et fait augmenter la proportion de spermatozoïdes anormaux dans les éjaculats des coqs de souche chair.

Acidic ethanol extraction of cottonseed

Ethanol (EtOH) is being evaluated as an alternate solvent to hexane for the extraction of glanded cottonseed. Hot EtOH, needed for efficient oil and aflatoxin extraction, binds gossypol to protein. However, this binding can be minimized by acidifying aqueous EtOH with a tribasic acid, such as phosphoric or citric. While this solvent extracts oil and gossypol, it does not affect EtOH’s ability to extract aflatoxin. The defatted cottonseed meals produced from this process contained 0.03% total gossypol (which is lower than meal prepared by most other processes) and the aflatoxin content was reduced from 69 to 2.9 ppb. These are preliminary results and additional research is needed to determine commercial feasibility. The removal of essentially all gossypol from an extracted meal has the potential to expand the use of cottonseed meal as a feed, increasing its value to both the cotton farmer and the seed processor.

Ion-pair, liquid chromatographic analysis of total gossypol in chicken liver

An ion-pair, liquid chromatographic method for the determination of total gossypol in chicken liver has been developed. It involves hydrolysis of bound gossypol in the presence of ascorbic acid, partitioning into chloroform and isocratic separation on Spherisorb ODS2, 10 μm, column with a methanol-water mobile phase containing octane-1-sulfonate. Precision data based on within-day and between-days variation suggested an overall relative standard deviation of 8.1%, while overall recovery was 81.1%±3.

Determination of Total Gossypol in Cottonseed and Cottonseed Meals by Derivative UV Spectrophotometry

A new method for the determination of total gossypol in cottonseed and cottonseed meals has been developed. The method involves oxalic acid hydrolysis of the bound gossypol in a methyl ethyl ketone-water azeotrope, partitioning the liberated gossypol into chloroform, and quantification by 2nd derivative UV spectrophotometry. The 2nd derivative transformation and measurement of the conventional analytical band around 300 nm permits direct quantification of all compounds containing naphthalene nuclei; chromogenic reaction is not required. The method was tested at concentration levels of total gossypol normally expected for cottonseed and cottonseed meal. Precision and accuracy data suggested an overall relative standard deviation of 4.0% and an overall recovery of 89.5%. Although results for cottonseed and solvent-extracted cottonseed meal analyses were comparable to those obtained by use of American Oil Chemists' Society methods, results were lower for screw-pressed meals. The lower results were attributed to the partial conversion of gossypol, during the cooking process of these meals, to compounds that differ in composition and structure from gossypol and which react with aniline to give false readings.

Determination of free and total gossypol by high performance liquid chromatography

AbstractExisting HPLC methods determine only pure gossypol whereas the official AOCS method determines both gossypol and other physiologically active gossypol‐like compounds that react with 3‐amino‐1‐propanol and aniline. The feed industry uses the official AOCS method, which is complex and produces results that do not correlate well among laboratories. HPLC methods were developed, using 3‐amino‐1‐propanol as a complexing agent, for the quantitative determination of free and total gossypol in cottonseed meal, oil, and ethanolic miscella. These methods are simple, sensitive, and provide reproducible results. In addition the use of toxic aniline is eliminated.

Effect of Feeding Gossypol in Cottonseed Meal on Growth, Semen Quality, and Spermatogenesis of Yearling Holstein Bulls

Yearling Holstein bulls were fed a corn silage ration supplemented with either cottonseed meal with gossypol or soybean meal in two trials to evaluate the effect of feeding gossypol on reproductive characteristics. In Trial 1, roughage to concentrate ratio was 88:12 and was fed for 60 d. In Trial 2, roughage to concentrate ratio was 50:50 and was fed for 42 d. Cottonseed meal concentrate had 3.03g total gossypol/kg DM. Cottonseed meal concentrate was fed to provide 6 and 30mg total gossypol/kg BW per d in Trials 1 and 2. Ejaculates were collected twice weekly via artificial vagina and critiqued for quantity and quality before and after thawing and after postthaw incubation. Leptotene spermatocytes to Sertoli cell ratio in stage 1 tubules was used to evaluate spermatogenesis. Growth characteristics and tissue total gossypol concentrations were also evaluated. No gossypol was found in plasma taken before, during, or after Trial 1 or from body organs or plasma taken during or after Trial 2. No signs of gossypol toxicity were observed, and growth characteristics were similar on both rations. Gossypol in cottonseed meal fed at low to moderate concentrations was not deleterious to seminal quantity or quality, and spermatogenesis was unaffected by treatment.

Determination of total gossypol at parts‐per‐million levels

AbstractThe official AOCS method Ba 8‐78 for total gossypol has been modified by introduction of two clean‐up steps. These steps reduce sample blanks and also substantially increase the concentration of dianilinogossypol available for spectrophotometric measurement. An improved method of correcting sample absorptions for blanks, which reduces the possibility of over or under compensation, and criteria for judging the quality of the results have been added. With these modifications, the method is more than adequate for grading glandless cottonseed under Rule 112 of the National Cottonseed Products Association. As little as 1 ppm can easily be measured in sound cottonseed samples. The method is not universally applicable to mixtures that may contain TG, but the criteria of quality should permit identification of samples to which it is not applicable and, hence, prevent reporting of inaccurate TG concentrations. Additional modifications for use with foods and other complex mixtures are suggested.

Spectrophotometric determination of total gossypol in cottonseeds and cottonseed meals.

Description d'une methode simple et rapide de dosage du gossypol apres reaction avec l'amino-3-propanol-1 et complexation avec le fer (III). Le complexe presente une couleur verte que l'on dose par absorption a 620 nm