VANILLA.
N.F. VANILLA Vanill. [Vanilla Bean] Bourbon or Indian Ocean vanilla, produced in the Isle of Reunion, resembles Mexican vanilla, but is scarcely so long in the tapering portions, is of a dark brown almost black color, is not so firm as the Mexican, has the surface smooth and waxy, and soon becomes covered with a coating of acicular crystals known as " frost." The odor of this vanilla is said to resemble that of Tonka bean rather than that of Mexican vanilla. The Seychelles and Mauritius vanilla (inferior Bourbon of the trade) has the pods about six inches in length, not over a quarter of an inch in width, and characterized by the pale color, the faint odor, and a smooth but not waxy surface. South American or Guadeloupe vanilla resembles the Mexican bean, but is usually recognizable, when the bean is entire, by the latter being broad and flattened, usually half an inch or more wide, slightly tapering at the lower end, and at the upper sharply attenuated an inch or so at the point. It has a reddish brown color, and is of a rank odor. It is very pulpy, with a surface intermediate in feel between the Bourbon and the Mexican, and having but few crystals. One variety of this vanilla, sold under the name of vanillons, has the odor of heliotrope and is much used by perfumers and tobacco manufacturers. Tahiti vanilla, has its pods from six to seven inches long, flat, from three-eighths to half an inch wide, with a reddish-brown color. They are almost destitute of vanilla flavor, and have an odor suggesting heliotrope. It is said they contain piperonal and also vanillin. According to Constantin and Bois (P. J., 1915, xcv, 360), there are two other sorts of vanilla grown in Tahiti; one is from a plant that they regard as a variety of v. planifolia from which it differs in the characters of .foliage and the shape of the labellum in the flower; they propose to call it V. planifolia var. Augusta. The third sort has a flavor resembling that of the Java bean and a pleasant odor with an after-taste of heliotrope. They have not seen the flowers of this. Java vanilla, which is almost exclusively consumed in Holland, has a pod from four to six inches long, with a flavor as fine as that of the Mexican bean, and a much stronger odor. Description and Physical Properties. Unground Vanilla.-Fruit linear, flattened, from 15 to 35 cm. in length and from 5 to 9 mm. in width; apex terminating in a flat circular scar; gradually tapering, more or less bent and curved or hooked at the bases, or in the Tahiti variety, broad in the middle and tapering towards either end, the base closely resembling the summit; externally blackish brown, longitudinally wrinkled, moist-glossy; occasionally with an efflorescence of vanillin in the form of acicular crystals or monoclinic prisms; frequently with narrow, elliptical or irregular, more or less wrinkled, dark-brown patches of cork, occasionally split into three parts near the tip, flexible and tough, one'-celled, containing a blackish brown pulp and numerous blackish brown seeds; the latter being flattened, irregularly triangulate or nearly circular in outline ; reticulate and varying from 0.25 to 0.3 mm. in diameter. Odor and taste characteristic and very agreeable. Structure. Epidermis with a somewhat thickened outer cuticularized layer having occasionally rounded or conical masses of an excretion of a gum like substance; a layer of collenchyma of one or two rows of cells; a thick sarcocarp composed of parenchyma cells in which is imbedded an interrupted circle of fibro vascular bundles; the parenchyma cells are deeply undulate in outline and usually contain a thin protoplasmic layer enclosing numerous oily globules or may contain bundles of raphides of calcium oxalate; the individual crystals varying from 0.2 to 0.4 mm. in length; some of the parenchyma cells are specially modified and distinguished by their somewhat thickened walls with long, oblique, slit like pores or the thickening may extend in the form of broad, spiral bands; in the fibro-vascular bundles the phloem is central, being more or less surrounded by a few tracheae, the walls possessing slit-like pores or spiral thickenings, and at the outside of the bundle is a closed circle of fibers, the walls being thin, strongly lignified, provided with numerous transverse, simple pores, the outer wall of the outer row of fibers being irregular or sinuate; from the inner walls of the endocarp arise the placentae bearing numerous brownish red or blackish seeds, and from the cells of the endo-carp also arise numerous long, nearly straight hairs, the ends being rounded, the hairs being more or less matted together by a gummy or resinous mass in which some of the seeds are held; in mounts made in chloral hydrate T.S. or potassium hydroxide T.S., the immature, brownish red seeds show a deeply reticulate seed-coat, with cells of an oblong-polygonal form in surface view. Place a few of the crystals, occurring as an efflorescence on the fruit, on a microscope slide or watch crystal and add a drop of phloroglucinol T.S. and hydrochloric acid; the solution immediately acquires a carmine-red color ( distinction from benzoic acid) .The amount of extractive yielded to dilute alcohol should not be less than 12 %." N .F. A characteristic test for the vanillin crystals which occur as an efflorescence on the fruit is as follows: On a microscope slide or watch crystal, place a few crystals and add a drop of phloroglucinol T .S. and hydrochloric acid; the solution immediately acquires a carmine-red color (distinction from benzoic acid) .The amount of extractive which vanilla of good quality yields to dilute alcohol should not be less than 12 per cent. Nor should it yield more than 6 per cent. of ash. Vanilla beans from which the vanillin has been removed by means of a solvent are sometimes offered for sale. The fraud is to be detected by the absence of flavor and odor. Such beans, and also beans of an inferior quality, are sometimes " unproved" in appearance and in odor by the use of benzoic acid. For the detection of this fraud the pharmacist should avail himself of the fact that while the crystals of benzoic acid are flattened and rhomboidal and generally lie upon the bean, those of vanillin are usually acicular and stand out at right angles from the surface of the fruit. The absence of the crystalline coating on the vanilla beans seems to be no proof of inferiority, for Henri Lecomte affirms that it is not rarely absent in the best Mexican bean. (B. Sc. Pharm., 1901.) Constituents.-The vanilla fruit when fresh possesses none of the pleasant aroma which we associate with the fruit, the odor being developed during the process of curing. There is present in the fruit the glucoside coniferin and two ferments. Under the action of these successively, the coniferin is first changed into coniferyl alcohol and thence into vanillin. Coniferin has been separated in the pure state not only from this plant but from several species of pine trees (see Pinus Strobus). Coniferin forms white crystalline needles having a composition of C16H + 2HaO. These are efflorescent in dry air and when anhydrous have a melting point of 185 C. Coniferin is practically insoluble in cold water, but soluble in alcohol and slightly so in hot water, its solution having a bitter taste. It may be hydrolyzed by either sulphuric or chromic acid as well as by the ferments found in the vanilla bean. ( See Vanillinum.) H. Lecomte (J. P. 0., 1903, 343) studied the conditions which bring about the formation of vanillin. According to his researches, there exist in the vanilla plant two ferments, which differ in a marked degree from each other in their functions. The one, an oxydase, is present in the individual organs of the plant, such as the leaves, shoots and their aqueous extracts, in the green and ripe fruit, and in the prepared commercial fruit. The second ferment is contained in the sap of the vanilla, and acts as a hydrolyzing ferment. Both ferments, the oxydase as well as the one possessing the hydrolytic action, appear to be necessary for the formation of vanillin in the plant, and their action may possibly be explained thus : During the preparation the coniferin produced by the plant is split up into glucose and coniferyl alcohol. This process would explain also the occurrence of grape-sugar in vanilla. The oxydase then converts the coniferyl alcohol into vanillin. Tiemann and Haarmann obtained from Mexican vanilla 1,69 per cent. of vanillin, from Reunion vanilla 2.48 per cent" from Java vanilla 2.75 per cent. Uses -Vanilla is used solely as a flavoring agent; it is an ingredient of several N.F. preparations. Vanilla Poisoning.-Cases of violent gastro intestinal irritation from eating vanilla ices have been reported. Most of these undoubtedly were due to tyrotoxicon, a ptomaine produced in decomposing milk; but if the one reported by Rosenthal {P. J., xv, p. 24) be accurately stated it must be allowed that in some instances the vanilla itself is at fault. In this connection the reports of Claverie (J. P. C., Supp. 1908, xxv ) of violent dermatitis in workmen handling vanilla beans is of interest. He attributes the symptoms to the oily exudate of the vanilla pods. Off. Prep.-Tinctura Vanillae, N.F. Further reference to Vanilla may be found by using the site search box at the top right hand of the page or by returning to the main library.
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