Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/270

 fying 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.

RICE (Oryza sativa).

Rice is one of the most important food cereals. It furnishes a large part of the food of the inhabitants of China and Japan. It is a food rich in starch and poor in protein, and furnishes, therefore, heat and energy, and is well adapted for the nourishment of those engaged in hard labor or who undergo extreme physical exertion. The cultivation of rice is rapidly extending in the United States, especially in Louisiana and Texas. The statistical data relating to the rice crop for 1906 are as follows:

Acreage,            575,014 acres Production,      17,854,768 bushels Yield per acre,          31.1 " Price per bushel,         90.3 cents Total value,      16,121,298 dollars

The adulteration of rice is confined to coating it with talc, paraffin, and glucose. The object of this treatment is to give a better appearance to the grain and to protect it from the ravages of insects. The use of indigestible substances such as talc and paraffin is scarcely justifiable. The starch granules of rice have distinctive properties which enable them to be readily recognized under the microscope, as shown in Fig. 30.

The rice starch grains are polygonal in form and have sharp angles. The