CHAPTER XIV.

ARROWROOT AND ITS ADULTERATIONS.

DEFINITION OF ADULTERATION.

Any other starch or farina than that indicated by the name under which it is sold, or any added vegetable or mineral substance. Arrowroot should be distinguished rather by the name of the plant from which it is derived than by that of the locality in which it is grown. Mixtures of more than one kind of arrowroot to be sold as mixtures.

THE term 'arrowroot' was originally applied to the rhizome or root of Maranta arundinacea, in consequence of its supposed efficacy in counteracting the effects of wounds inflicted by poisoned arrows.

Of late years the signification of the term has been much extended, and it is now employed to designate almost every fecula which bears any resemblance to true or Maranta arrowroot, no matter how dissimilar the plants may be from which it is obtained."

Attending this enlarged use of the word arrowroot are certain disadvantages. Many persons consider that all arrowroots constitute one and the same article, varying only in quality, and according to the place from which they are procured; while but few persons are aware that there are several distinct kinds of arrowroot, the produce of different plants, great uncertainty and confusion being thus created.

To increase this confusion, the word 'genuine' is often prefixed to the term 'arrowroot,' and as there are several kinds of arrowroot, so must there be several genuine arrowroots. These vary in value from a few pence to two or three shillings the pound-from, in fact, the value of genuine Maranta arrowroot to that of genuine potato arrowroot. With these particulars the public at large are but ill acquainted.

The difficulty and confusion are still further enhanced by applying to the arrowroot, as is generally done, the name of the place from which it is obtained; thus we have genuine West Indian, Jamaica, Demerara, Bermuda, St. Vincent, East Indian, Brazilian, African, Guinea, Sierra Leone, Portland, British, and a variety of other arrowroots. Some persons suppose that each of these names represents a different kind of arrowroot; others imagine that they all indicate one and the same production; while the fact is, that in some cases, as in that of East India arrowroot, one name may be indiscriminately applied to two distinct kinds of arrowroot, and in others, six

or eight names all signify but a single kind or species, as is the case with West India arrowroot. This great variety of names is objectionable, not merely because it tends to confuse the public, but because it offers to the fraudulent great facilities for adulteration and imposition, of which, as we shall see hereafter, they have not failed to avail themselves.

The remedy for this state of things is simple; each really distinct arrowroot, that is, every arrowroot which is the product of a distinct plant, should be designated by the name of the species from which it is derived, as Maranta, Curcuma, Tacca, Manihot, Arum, Potato Arrowroot, &c.

The employment of these terms should not be optional, but compulsory, for the better protection of the public against fraud in this article of food. The propriety of this suggestion will become still more evident as we proceed.

We shall now describe each kind of arrowroot separately, observing of them all, that when pure they are non-nitrogenised substances, and therefore adapted to the formation of the fat of the body, and to the maintenance of respiration and temperature.

MARANTA ARROWROOT.

Maranta arrowroot is obtained from the rhizomes of Maranta arundinacea, one of the family of the Marantacea.

A rhizome is an underground jointed stem placed horizontally in the earth, giving off from its upper surface branches, and from the lower radicles or roots; the starch or fecula is contained in the joints of the rhizome, being deposited in innumerable minute cells.

The following account of its preparation is given by Dr. Pereira in his Materia Medica':

'The starch, or fecula, is extracted from the roots (tubers), when these are about ten or twelve months old. The process is entirely a mechanical one, and is performed either by hand or by machine.

In Jamaica it is procured as follows:-The tubers are dug up, well washed in water, and then beaten in large, deep, wooden mortars to a pulp. This is thrown into a large tub of clean water. The whole is then well stirred, and the fibrous part wrung out by the hands and thrown away. The milky liquor being passed through a hair sieve, or coarse cloth, is suffered to settle, and the clear water is drained off. At the bottom of the vessel is a white mass, which is again mixed with clean water, and drained; lastly, the mass is dried on sheets in the sun, and is pure starch.

In Bermuda the roots are first deprived of their paper-like scales, and then rasped by a kind of wheel rasp, and the fecula well washed through sieves and carefully dried.

Upon the Hopewell estate, in the island of St. Vincent, the carefully skinned tubers are washed, then ground in a mill, and the pulp

washed in tinned copper cylindrical washing-machines. The fecula is subsequently dried in drying houses. In order to obtain the fecula free from impurity pure water must be used, and great care and attention paid in every step of the process. The skinning or peeling of the tubers must be performed with great nicety, as the cuticle contains a resinous matter, which imparts colour and a disagreeable flavour to the starch. German silver palettes are used for skimming the deposited fecula, and shovels of the same metal for packing the dried fecula. Th drying is effected in pans covered by white gauze, to exclude dust and insects.'

Fig. 110.

Starch granules of MARANTA arrowroot, called commonly West India arrowroot. Drawn with the Camera Lucida, and magnified 240 diameters.

The root furnishes, according to Benzon, about 26 per cent. of starch.

Pure and unadulterated Maranta arrowroot should be of a dull and opaque white colour, crepitating or crackling when pressed between the fingers, and treated with about twice its weight of concentrated hydrochloric acid it should yield an opaque paste.

The above characters and appearances may all, however, be assumed by certain of the other arrowroots; the microscope, therefore, affords

the only ready and certain means of distinguishing this arrowroot from all other species, and these again from each other.

Characters of the starch corpuscles.-Examined with that instrument the granules or particles of Maranta arrowroot are found to be usually more or less oblong and ovate, but sometimes they are musselshaped or even almost triangular; they vary considerably in size, but each of the larger granules is marked by a number of delicate concentric lines; at the broad or large extremity of each a distinct spot is visible, ordinarily considered to be a cavity, and denominated the 'hilum;' this spot is sometimes circular, but most frequently it is seen as a short, sharp line, running transversely across the granule; it furnishes a most distinctive feature by which Maranta arrowroot may be at all times very readily identified (fig. 110).

When boiling water is added to Maranta or any other arrowroot, its physical condition undergoes a great and surprising alteration, the nature of which may be clearly traced by means of the microscope. A tablespoonful of arrowroot, on which a pint of boiling water is poured, immediately loses its whiteness and opacity, becomes transparent, and the entire of the water is as it were converted into a thick and jellylike substance. If a little of this be diffused through cold water, and examined with the microscope, it will be seen that the starch granules are altered amazingly: they have increased to twenty or thirty times their original volume; they are more or less rounded; the concentric lines and the hilum are obliterated; the membrane of each granule is ruptured, and a granular matter has escaped from its interior.

The appellations which have been bestowed upon Maranta arrowroot are very numerous; their use ought to be wholly discontinued, for the reasons already assigned: thus it is sometimes called West India arrowroot, Jamaica, Demerara, Bermuda, Berbice, St. Vincent arrowroot, &c. The impropriety of denominating it West India arrowroot is shown by the circumstance that the Maranta plant is cultivated in the East as well as in the West Indies.

CANNA, OR TOUS LES MOIS ARROWROOT.

Canna edulis, the plant from the tubers of which the starch known as Tous les Mois is obtained, belongs to the natural order Marantaceæ, which includes Maranta arundinacea, or West India arrowroot.

The starch is obtained much in the same manner as that of the other arrowroots; that is, the tubers are rasped, and the fecula separated from the pulp by washing, straining, decantation of the supernatant liquor, and desiccation of the deposited starch. It is imported from

St. Kitts.

The jelly yielded by it is said to be more tenacious, but less clear and translucent, than that of other arrowroots.

Owing to their large size, the starch granules exhibit a glistening or

satiny appearance; they differ from other dietetic starches not only in their much greater dimensions, but in certain other particulars.

Characters of the starch corpuscles.-The granules or corpuscles are nearly all very large, flat, broad, but ovate; sometimes, like those of East India arrowroot, pointed at the narrow end. The hilum is situated in the narrow extremity of the granule, and the rings are exceedingly fine, regular, and crowded (fig. 111).

The only starch with which they are at all likely to be confounded is that of the potato; the granules are, however, larger, of a different shape, being flat, and the striæ are much more regular and numerous.

Viewed by polarised light the crosses are more regular than in potato starch.

CURCUMA ARROWROOT.

Curcuma arrowroot is obtained from the tubers of Curcuma angustifolia, one of the family of the Zingiberacea.

The mode of its preparation does not differ materially from that practised in obtaining the fecula from the tubers of Maranta arundinacea, and which has already been described.