Spices and How to Know Them

CAPSICUM STARCH Fig. 20 is nearly circular or rounded polyhedral in forms with scarcely visible rings, and in most cases a depressed hilum, resembling in size and shape corn starch, but having peculiar irregularities which distinguish it, such as rosette-like formation on a flattened granule, or a round depression at one end. It does not polarize as actively as maize starch and can be distinguished from rice by the greater angularity of the latter. PEPPER STARCH Fig. 21 is the most minute starch which is usually met with, not averaging over .001 millimeter nor exceeding .005. It is irregularly polyhedral and polarizes very well, but requires a high power to discover any detail when a hilum is found. It cannot be confused with other starches. CINNAMON STARCH Figs. 22 and 23 have an extremely irregular polyhedral or distorted granules, often united in groups with smaller granules and adherent to the larger ones. In size, it varies from .001 to .025 millimeter, averaging nearly the latter size. In some granules the hilum can be distinguished, but no rings; it is readily detected with polarized light. BUCKWHEAT STARCH Fig. 24 is very characteristic. It consists of a chain or groups of angular granules with a not very evident circular nucleus and without rings. The outline is strikingly angular and the size not very variable, being about .01 to .015 millimeter. MAIZE OR CORN STARCH Figs. 25 and 26 have granules largely of the same size from .02 to .03 millimeter in diameter, with now and then a few which are much smaller; they are mostly circular in shape or, rather, polyhedral with rounded angles. They form very brilliant objects with polarized light, but with ordinary illumination show but the faintest signs of rings and a well-developed hilum, at times star-shaped and at others more like a circular depression. RICE STARCH Figs. 27, 28, and 29, is very similar to corn starch, and is easily confused with it, being about the same size. It is, however, distinguished from it by its polygonal form and its well-defined angles. The hilum is more prominent and more often stellate, or linear, and several grains are at times united. [Illustration: Fig. 22. PURE CINNAMON Fig. 23 _Cinnamon_ Fig. 25. MAIZE STARCH Fig. 26 _Corn_ Fig. 41. PURE CASSIA] [Illustration: Fig. 30. WHEAT STARCH Fig. 31 _Wheat_ Fig. 32. BARLEY STARCH Fig. 33 _Barley_] WHEAT STARCH Figs. 30 and 31 are quite variable in size, varying from .05 to .012 millimeter in diameter, and this starch belongs to the same class as barley and rye; the hilum is invisible and the rings are not prominent; the granules are circular disks in form, and there are now and then contorted depressions, resembling those in the pea starch; it is the least regular of the three starches and does not polarize actively. BARLEY STARCH Figs. 32 and 33 are quite similar to that of wheat, but barley starch does not vary so much in size, averaging .05 millimeter. It has rings more distinct and very small granules adhering to the largest in bud-like forms. RYE STARCH Fig. 34 is more variable in size, many of the granules not exceeding .02 millimeter while the largest reach .06 to .07 millimeter. It lacks distinctive characteristics entirely, and is the most simple in form of all starches described. OAT STARCH Figs. 35 and 36, is unique, being composed of large compound masses of polyhedral granules from .12 to .02 millimeter in length, the single granules averaging .02 to .015 millimeter. It does not polarize actively, as may be seen in the figures, and displays neither rings nor hilum. The first sign of maize or corn meal as an adulterant is the thin outer coat which becomes detached in milling and is not readily crushed. In yellow corn it has a pinkish color, and simple, longitudinal cells. Broken rice is sometimes used as a dilutant; it may be recognized by the brilliant appearance of the hard white particles which may be picked out of the spice under a hand lens. The two cereals named (broken rice and maize corn) are the only ones which are commonly met with that introduce starch. Wheat bran (Fig. 37) is occasionally added, which can be recognized by its distinctive structural character and is better understood from an authentic specimen, which should be soaked in chloral-hydrate. As modified cereals, we find refuse bread, cracker dust, and stale ship bread, in which the wheat starch is much changed from its original form by the heat and moisture, so that at times it might be confused with leguminous starch, but the softness of the particles and the ease with which they fall to pieces in water reveal their true name. Oil seed, oil cake, and husk (Figs. 38, 39, and 40) are very commonly used and are readily recognized by the peculiar structure of the outer coats of the seed. The particles, which can be usually found and selected with a dissecting microscope, should be examined in alcohol or glycerine, or a mixture of the two, as the outer coats of some seeds, such as mustard, are swollen by water and become indistinct. Many varieties of the cruciferous seeds resemble it very much, so that it is difficult to distinguish them, but it is generally recognized by the outer layer of hexagonal cells and a middle and inner coating, which consists of peculiar angular cells, the latter being much larger than the former, which are the most characteristic feature, and should be compared with seeds of known origin. After soaking in chloral-hydrate, the remaining interior layers are, perhaps, more easily made out, in some cases, after moderate bleaching with nitric acid and chlorate; the interior of this seed is not blued by iodine. Peanut, or ground nut cake, is recognized by the characteristic structure of the red-brownish coat, which surrounds the seed, and consists of polygonal cells with peculiar saw-toothed thickening of the walls. The seed itself consists of polygonal cells full of oil and starch granules, which are globular in form and not easily confused with pepper starch. The structure of the brown membrane is best made out in chloral-hydrate, which removes the red color and leaves the fragments of a bright yellow. Linseed cake is distinguished by the fact that its husk is made up of one or two characteristic elements. The outer coat, or epidermis, is colorless and swells up in water, forming a mucilage, like the mustard seed. Beneath this is a layer of thin, round, yellow cells, while the third is very characteristic and consists of narrow and very thick-walled dotted vessels; next to these is an inner layer of compact polygonal cells, with fairly thin, but still thickly dotted, white walls and dark-brown contents containing tumeric. The endogen and embryo are free from starch and will not color yellow by potash, as is the case with mustard and rape seed cake. [Illustration: Fig. 35. OAT STARCH Fig. 36. _Oats_ Fig. 37. WHEAT BRAN Fig. 46. POWDERED ALLSPICE SHOWING PORT WINE CELLS. (A) STARCH] Cocoanut shells are often used, and have numerous, both long and short, stone cells and spiral vessels from this fibrous tissue; the long stone cells having thinner walls than the shorter cells, all of which are readily seen after bleaching. When the shells are roasted, they refuse to bleach, and it is then only possible to class the particles, on which the reagents do not act, as roasted shells or charcoal, which are frequently used in pepper to give desired color to material rendered too light by white adulterants. Buckwheat, after bleaching, shows a preponderance of tissue made up of long, slender, and pointed sclerenchyma cells and a smaller amount of reticulated tissue, resembling the cereals somewhat and cayenne pepper. Portions of the interior of the seed are also visible and consist of an agglomeration of small hexagonal cells which originally contained starch. The starch is readily recognized by its peculiar characteristics. The sclerenchyma is, of course, optically active and forms a beautiful and distinctive object with polarized light. Sawdust of various woods may be recognized by the fragments of various spiral and dotted vessels and fibrous material which are not found in spices or in other adulterants. Rice bran is made up prominently of two series of cells at right angles to each other, which make up the outer coats of grain, the structure being best made out after soaking in chloral-hydrate; the cells of one series are long, small, and thin-walled, and are arranged in parallel bundles; the others have very much thicker walls and are only two or three times as long as they are broad. Clove stems are distinguished by their peculiar yellow dotted vessels and their large and quite numerous cells, neither of which is seen prominently in the substances which are adulterated. The peculiarities of adulterants should be carefully confirmed and the eye trained by practice so as to become accustomed to recognizing their structure by a study of the actual substance. Take one gram of powdered spice which will pass a 60-mesh sieve and dry at 150 degrees to 110 degrees C. in an air bath provided with a regulator, until a successive weighing shows a gain, which denotes that oxidization has begun, which takes about 12 hours, or over night; the loss is water, together with the largest part of volatile oil. Deduction of the volatile oil, as determined in the ether extract, will give a close approximation of water. The ash portion is determined by incineration at a very low temperature, such as may be attained in a gas muffle, which is the most convenient arrangement for work of this kind. The proportion of ash insoluble in acid may be determined where there is a reason to believe that sand is present. To find the amount of volatile oil by ether extract: Two grains of substance are extracted for twenty-four hours in a siphoning extraction apparatus, being first placed in a test tube, which is inserted into a continuous extraction apparatus of the intermittent siphon class, the tube used being an ordinary test tube, the bottom of which has been blown out. A wad of washed cotton of sufficient thickness is put in the lower end of the tubes to prevent any solid particles of the sample from finding their way into the receiving flask; another wad of cotton is packed on top of the sample, and the apparatus is then so adjusted that the condensed ether drops into the tube and percolates through the sample siphons into the receiving flask. In this way the operation is continued the length of time named. The best ether should be used to avoid extracting substances other than oil soluble in alcohol, and to continue the extraction for at least the time named, as piperine and several other proximate principles are not extremely soluble in ether. On stopping the extraction, the extract is washed into a light, weighed, glass dish, and the ether is allowed to evaporate spontaneously, but not too rapidly, for the reason that water, which is difficult to remove, might be condensed into the dish. In a short time the ether will disappear, and the dish is placed in a dessicator with pumice and sulphuric acid, not with chloride of calcium, which has been shown to be useless. It is allowed to remain over night to remove any moisture; the loss of oil by this process is scarcely appreciable. The dish is next weighed and afterward heated to 110 degrees C. for some hours, to drive off the volatile oil, beginning at a low temperature, as the oil is easily oxidized, and then is not volatile oil. The residue is weighed, the difference being calculated to volatile oil and examined as to its composition of purity. [Illustration: Fig. 11. _Tumeric_ Fig. 12. GINGER ADULTERATED Fig. 13. PURE GINGER Fig. 14. _Ginger_ Fig. 19. _Nutmeg_ Fig. 24. _Buckwheat_ Fig. 34. _Rye_] Alcohol extract is made in the same manner as the ether extract, using, of course, the substance extracted. The solvent may be either absolute alcohol—that of 95 per cent. by volume, or 80 per cent. by weight, the latter being preferable in most cases, as there is no definite point with the stronger spirit at which the extraction is completed. The amount of reducing material produced by boiling the spices with dilute acids serves with several as an index of purity. In the case of pepper, which contains a large amount of starch, the addition of fibrous adulterants reduces the equivalent of reducing sugar, which are indicated in the solution after boiling with acid. Tumeric is always found in spices, such as cloves and pimento of good quality.