Constituents of crude cottonseed oil

Summary Crude cottonseed oil contains in addition to the constituents previously reported a lecithin type of phosphatide which gives an ether-soluble compound with cadmium chloride. This phosphatide can only be partially removed from the oil by extraction with alcohol. It has been found in the “settlings” from this oil. The treatment of the oil with water causes only a partial separation of this phosphatide. The phosphatides, resins, and presumably other substances present in small quantities in the crude oil have emulsifying properties and are undoubtedly the cause in part for the retention of oil in the soap stock when the oil is refined by caustic soda.     

Constituents of crude cottonseed oil

Summary The alcohol-soluble portion of the settlings which separate from clear crude cottonseed oil has been studied further. Although the oil had stood in the laboratory for about 3 years before the settlings were removed for the investigation, it was free from rancidity and in excellent condition. Palmitin, amounting to about 25 per cent, and di-palmitin, amounting to about 1 per cent of the total settlings, were isolated and identified. About 0.1 per cent of a phytosteroline, which gave an acetyl derivative melting at 166° to 167° C., was obtained. It appears from the results of this investigation that the dipalmitin, which was probably produced by the hydrolysis of a very small quantity of a tri-glyceride, accounts in part for the acetyl value obtained with cottonseed oil. As no investigation has succeeded in showing the presence of any hydroxy acids in cottonseed, or for that matter in many other oils giving a comparatively small acetyl value, the values noted may be largely due to the presence of small quantities of various di-glycerides.     

Refining method for crude cottonseed oil

Conclusion Acknowledgment is again given to Mr. Nelson W. Humbaugh who carried out the analytical work here recorded. A proposed revision of the refining method as at present written which is intended to embody all the points found desirable, is now in the hands of the members of the Refining Committee for consideration and test.     

Estimation of gossypol in crude cottonseed oil

Summary 1. Pyridine promotes the precipitation of gossypol by aniline from oil solutions. A quantitative method for the estimation of gossypol in crude hot pressed cottonseed oil is outlined, which involves the use of a pyridine-aniline (4:1) reagent. 2. Samples of crude oils from six different mills analyzed from 0.049 to 0.105 per cent gossypol. 3. Gossypol in crude oils is rendered non-precipitable by heating the oil to 150° C. for 30 minutes. Heating at lower temperatures decreases the yield. 4. Photomicrographs are presented which show the crystal form of dianiline gossypol precipitated in the presence of pyridine. This work was carried out under the direction of L. C. Haskell, to whom grateful acknowledgment is made. The writer is indebted to M. C. Kibler for assistance in conducting the analyses.     

Net loss in crude cottonseed oil refining

Reasons are given for failure to arrive at a satisfactory materials balance on the crude oil refining operations, and a simple laboratory method is proposed for evaluating the refinery foots which avoids the necessity of obtaining their amount or analysis.     

Refining crude cottonseed oil dissolved in hexane

Measurements were made of the surface tensions of mixtures of cottonseed oil and hexane and of their interfacial tensions against water and caustic soda solutions. Attempts were made to study the reaction rate between the two phases. The results show that in caustic refining of hexane miscellas the caustic is readily dispersed into the oil-hexane phase. Refining losses were found to be lower for miscellas containing less than 70% oil. Concentrations as low as 40% were refined successfully. The losses were inversely related to the viscosity of the solution. Sponsored by the Texas Engineering Experiment Station and the Cotton Research Committee of Texas, College Station, Texas.     

Gossypol content and refining losses on crude cottonseed oil

Summary 1. Gossypol has been found to be almost universally present in hot pressed crude cottonseed oils from all of the important cotton growing sections in the United States. 2. The average amount found in crude oils from 62 scattered mills was 0.05 per cent. The highest percentage found in a hot pressed oil was 0.210. Only 7 out of 124 oils failed to show the presence of gossypol. 3. Since gossypol content was not found to be proportional to deviation from average refining loss, it was concluded that at least a portion of the gossypol occurs in the oil in the bound state, associated with protein fragments.     

Continuous refining of crude cottonseed miscella

A simple, easily controlled process for continuous caustic refining of crude cottonseed miscella in a two-stage system is described. The effect of crude oil quality, oil: hexane ratios, temp, mixing conditions and chemical treatment are noted. The chemical reactions in the process are followed microscopically. The process yields a refined oil of less than: 1.0 bleach oil color, 0.03% free fatty acid and 15 ppm soap, and with 30~40% oil savings over Official Cup Loss. The by-product soap may be used advantageously in the meal from the extractor unit. Presented at the AOCS Meeting in Minneapolis, 1963.     

The pigments of crude cottonseed oils. I. The inhibition of color reversion in crude cottonseed oils

Summary Treatment of freshly prepared crude cottonseed oils withp-aminobenzoic acid and subsequent removal of the di-p-carboxyanilinogossypol formed makes it possible to store the oils at a relatively high temperature (37–38°C.) and for an extended period of time (30 days) without incurring any adverse changes in the refining and bleaching properties of the oils. In addition, a considerable decrease in the refining loss of the crude oil is obtained, and the stability of the bleached oil is not affected by the treatment. Spectrophotometric studies made during all phases of the chemical treatment and during the refining and bleaching procedures show that thep-aminobenzoic acid removes almost completely the gossypol-like pigments which are present in the crude oils and yields oils having the characteristic carotenoid spectrum. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

The effects of alkali cooking on the yields of crude and neutral oil from cottonseed meats

Summary Equal quantities of flaked cottonseed meats of identical composition were similarly cooked at high moisture conditions with and without alkali present. The cooked flakes were exhaustively extracted with commercial hexane, and the yields of crude oil, neutral oil, and meal were determined. The yields from an equal quantity of uncooked flakes were similarly determined, chiefly to serve as a neutral oil control. Analyses of the crude oils and meals were compared to determine the effects of the presence of alkali while cooking on the composition of the products. These experiments show that there was a reduction in the yields of both crude and neutral oil resulting from the admixture of alkali with cottonseed flakes while cooking. Assuming yields from flakes cooked with water as 100%, and average of 0.6% less crude oil was obtained from alkali-cooked than from watercooked flakes. A similar comparison of the yields of neutral oil shows that those from the alkali-cooked flakes averaged about 0.75% less than from the flakes cooked with water. The crude oils from alkali-cooked flakes contained only about one-fifth as much gossypol as those from the water-cooked flakes and were appreciably lower in free fatty acids. The crude oils from alkali-cooked flakes were significantly higher in phosphorus. The sodium content of the oils from alkali-cooked flakes indicated that their content of soaps ranged from 0.07% to 0.19%. Presented at the spring meeting, American Oil Chemists’ Society, New Orleans, La., April 28–May 1, 1957. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Solvent hydrogenation of cottonseed oil

Refined and bleached cottonseed oil was dissolved in a solvent (hexane, isopropyl alcohol, or di-isopropyl ether) and was then hydrogenated in a dead-end hydrogenator. Hydrogenation runs were conducted at temperatures from 115 to 145°C., at hydrogen partial pressures from 44 to 74 p.s.i.a., with catalyst concentrations varying from 0.05 to 0.40% nickel, and at high rates of agitation to climinate mass-transfer resistances. A series of hydrogenation runs was also made in which no solvent was used. The rates of hydrogenation for the various series of runs were in the same order of magnitude but decreased in the following order: nonsolvent, hexane, isopropyl alcohol, and di-isopropyl other runs. Selectivity and isomerization were low in all cases and essentially identical for solvent and nonsolvent runs. The rate of hydrogenation increased in all cases with higher catalyst concentrations. For the isopropanol runs, the reaction rate was maximum as a function of temperature at about 135°C. In the case of the other solvents, the rate of hydrogenation increased with increased temperature in the range from 115 to 145°C., but the rate increases of the solvent runs were less than those of the nonsolvent runs.