A study of the proteids of the corn or maize kernel.

  • Russell Henry Chittenden
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: A study of the proteids of the corn or maize kernel. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    fruit must necessarily be complicated by possible ferment changes, through which new bodies may be formed. Our study of the subject has naturally divided itself into three main parts: ist, a study of the proteids soluble in salt solutions, but insoluble in water ; 2d, a study of the proteids soluble both in water and in dilute salt solutions ; 3d, a study of the proteid matter soluble in alcohol, but insoluble in water and salt solutions. I. Proteids Soluble in Salt Solutions, but Insoluble in Water. Finely ground corn meal1 extracted with a 10-per cent, solu- tion of sodium chloride yields a slightly opalescent fluid, moder- ately rich in globulin-like bodies. A simple aqueous extract of ground corn likewise contains more or less globulin held in solu- tion by the salts dissolved from the corn. From both solutions the globulins are slowly precipitated by dialysis of the salts, and partially so by addition of water. They are, moreover, com- pletely precipitated, mixed with other proteids, on saturation of their solutions with ammonium sulphate. a. Direct extraction of corn meal with 10-per cent, solution of sodium chloride, and separation of the globulin by dialysis. In view of the well known action of water, in the presence of possible ferments, on the globulins of some seeds, the first extrac- tions of the corn kernel were made with salt solutions, with a view to diminishing the possibility of cleavage or dissociation of the normal proteids of the kernel. 5 kilos, of finely ground corn meal were therefore soaked in 8 litres of 10-per cent, solution of sodium chloride, with frequent stirring, for 24 hours, after which the fluid was strained off and the residue placed in a screw-press and squeezed dry. A second extraction of the meal was made with 4 litres of fresh salt solution, and the two extracts united. The solution was then filtered through thick filter-paper, yielding an almost perfectly clear yellowish filtrate. Tested by fractional heat-coagulation a series of coagulums were obtained commencing at about 35°-40°, a final one making its appearance as the solution was boiled. Further, the clear filtrate from this precipitate gave on addition of acetic acid a ■All the corn used in these experiments was of one variety, known as White Dent, and was freshly ground to a fine powder prior to each experiment.
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