In the dry substance:
| Protein, | 16.77 | percent |
| Ether extract, | 8.08 | „ |
| Crude fiber, | 1.38 | „ |
| Ash, | 1.94 | „ |
| Starch and sugar, | 73.20 | „ |
| Calories, | 4,875 |
It is evident from the above average analysis that the products examined are made from the whole kernel without the removal of the germ but with a very careful removal of the hull and bran. The composition of these products compares very favorably with the typical composition of the kernel itself. These data show the high nutritive value of these oat products, both in respect of fat and protein.
Fig. 29.—Oat Starch. × 200.—(Courtesy of Bureau of Chemistry.)
Adulterations.
—There are very few adulterations of oatmeal. Fortunately the price of this cereal is such that the admixture of other cereals would not be profitable. Doubtless such admixtures have often been made but evidently, from the examination of the products upon the open market, they are not very frequent. The characteristic appearance of oat starch is shown in [Fig. 29].
Oat starch grains average about 10 microns in diameter. There are usually present some grains of somewhat oval shape, which assist in identifying oat products when present. The starch granules also have a tendency to agglutinate into masses of varying size, as shown in the [photograph].
Detection of Adulterations.
—The adulteration of oatmeal with the flour of other cereals can easily be detected by the use of the microscope. Oat starch when highly magnified presents a peculiar cellular structure of pentagonal character which might be compared to the effect produced by grinding a large number of faces upon a precious stone. This peculiar appearance is caused by the tendency of the starch granules in oats to become compacted in large masses. The appearance of the separate granules and also the compact aggregate are shown in the figure on the preceding page. The large aggregated masses are of different sizes, ranging from .02 to 1.2 millimeters in length. These masses are usually broken up by grinding or pressure and, therefore, are not found in very great abundance in the commercial oatmeal. When separated into single granules these are found to be irregular in outline, due to the compression to which they have been subjected, more or less pentagonal in structure, and from .015 to .02 millimeter in diameter. The starch granules do not show any very marked characteristics under polarized light and have neither lines nor hilum. The above statements can easily be verified by any one who can operate an ordinary microscope, but before attempting to detect adulteration a careful examination of starch granules, prepared by the investigator himself, should be made.