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/352

 pearance of this starch under the microscope is shown in Fig. 45. The product of commerce is obtained from the rhizome and tubers.

Bermuda Arrowroot.—The Bermuda arrowroot is obtained principally from the Maranta arundinacea. This arrowroot is also produced very largely in St. Vincent and other West Indian localities. The granules of the starch are very much smaller than in the two species just described. The hilum is prominent, and frequently takes the shape of a well defined slit instead of the usual round spot. These arrowroots and those of South African origin are very extensively used for invalid foods where starchy foods are indicated, which, however, is not very often the case. These starches form a firm and semitranslucent jelly-like body when heated to the boiling point in a small quantity of water. The term arrowroot is applied to starch from plants of the origin mentioned because the natives of the country producing them use the bruised rhizomes as a poultice for wounds caused by arrows.

(× 200).—(Courtesy Bureau of Chemistry.)

Canna edulis.—This species of Cannaceæ also furnishes a starch of commerce nearly allied to the Canna indica. The common commercial name of this variety of starch is "Tous le mois." The starch granules of this species are rather larger than those of the Canna indica, and the concentric markings are more delicate and regular.