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.