Processing of cottonseed

Abstract

Summary The pigmentation of cooked cottonseed has been shown to depend principally upon the moisture content and period of heating of the seed. Several samples of crude hydraulic‐pressed and screw‐pressed oils produced under known processing conditions were found to differ markedly from each other with respect to their original colors and refining characteristics. The screw‐pressed crude oils were more deeply colored and contained one principal pigment, whereas the hydraulic‐pressed oils contained two principal pigments. The absence of significant amounts of gossypol in the crude oils has been demonstrated by means of a new technic for the quantitative isolation of gossypol. The crude oil pigments differed from gossypol, but like gossypol, they were removed during alkali refining. The pigmentation of the crude oils has been shown to depend principally upon the pigmentation of the original seed and the moisture content of the seed during cooking. On the basis of their absorption spectra it has been deduced that the alkali‐refined hydraulic‐pressed oils contain two to three pigments originally present in the crude oils whereas the alkali‐refined serewpressed oils contain these same pigments as well as a large number of decomposition products of the principal crude oil pigment.

Influence of condition of seed on the spectral properties of crude and processed hydraulic cottonseed oils

“…The cold hydraulic-pressed oils (Figures la, 2a, 4 maximum 374 m/~. This latter pigment is identical to that observed in the spectra of screw-pressed and commercial hexane-extracted cottonseed oils (1). As these cold-pressed hydraulic oils were obtained from the same lot of seed as the commercial hydraulicpressed samples, it would appear that there has been a modification of the pigments from gossypol with maximum at 368 m/~ and a gossypol-like pigment with maximum at 374 m/~ to two other gossypol-like pigments with maxima at 382 and 400 m/~ and furthermore this modification of the pigments appears to be an effect of heat in the commercial hydraulic extraction process.…”

“…In the spectral region between 480 to 640 mg those pigments responsible for the red color of cottonseed oils exhibit characteristic absorption. Principal among these is gossypurpurin (1). However absorption bands characteristic of gossypurpurin at 535 and 560 m~ are usually not detected in cottonseed oils except those extracted from seed stored at elevated temperatures (4) even though many cottonseed oils have a decided dark red color.…”

Gossypol, a Pigment of Cottonseed.

“…It is best to utilize cottonseed gums (177) or the "foots" from the alkali refining of solvent-extracted cottonseed oil (128) for the preparation of large quantities of gossypol. Extraction of intact pigment glands (36) or alkaline extraction of ethereal raw cottonseed extracts (35) are processes that may be used for the same purpose.…”

The reduction of free gossypol in cottonseed by pressure cooking

“…The genus Aesculus, because of the striking appearance and the abundance of the various species, has interested many investigators, and papers recording the results of their work have appeared since 1833 (7). Romanesi (8) in 1834 mentioned obtaining the oil by heating and pressing the nuts. Stillesen (11) in 1909 was the first person to carry out anything approximating a thorough investigation.…”

“…Also included in Figure 3 is a plot of data obtained by the Southern Regional Research Labora- tory (U.S.D.A.) on cooking raw cottonseed at a pressure of 10 to 12 p.s.i.g, and an initial moisture in the seed of 7.6% (8). For convenience of plotting the residual gossypols were corrected to an O.F.M.F.…”