Monograph of the U.S.D. 21st 1926
Compiled by Ivor Hughes.

VANILLA Vanill. [Vanilla Bean] Vanilla is the cured, full-grown, unripe fruit of Vanilla planifolia Andrews (Fam.Orchidacea) Vanilla should be preserved in  a cool place where it will not become brittle. Vanilla which has become brittle  should not be used. N.F.
Vanille. Fr.Cod.; Fructus Vanillae, PG Vanille, G.

Vanilla planifolia is a tall, perennial climbing epiphyte, with a very long,  smooth, dark green stem, much branched, and furnished at the nodes with aerial roots, which cling to the tree or the wooden framework supporting the plant. The dark green, tough leaves are alternate oval, sessile, attenuate at  the apex, fleshy and vein less. The pale greenish-yellow, sessile flowers are about two inches in diameter, and occur in loose, axillary racemes of twenty or more blossoms. The fruit is a slender capsule, seven or eight inches long, filled with an oily mass containing numerous small, black, shining seeds.

This plant is a native. of Mexico,
but is now widely cultivated  throughout the tropics and in greenhouses. Mexico, the Seychelles, Reunion and  Society Island yield the bulk of the beans of commerce. It does well from the  sea level up to two thousand feet of altitude, requiring for its perfection,  however, a moist, hot climate, with an habitual dry summer spell which seems to  be necessary to bring good flowering. It is propagated by means of cuttings,  sometimes two or three feet in length, but preferably from ten to; twelve feet  long, taken from growing shoots; these are planted after the dry season is over  and should produce flowers in two years.

Preferably placed upon trees, but sometimes on long stakes, trellises, wire  supports, etc., the slip is placed with one end on the ground, covered with  leaves or some light top dressing. In many cases the vines are planted so  closely as scarcely to leave room for cultivators to pass, but it has been found  that under these circumstances the. vanilleries are especially liable to  destructive fungous diseases. As the flower does not fertilize itself,  fertilization (pollination) by hand is necessary ; it is usually performed by  women and children. In most localities not more than thirty fertilized flowers should be left to  a plant. The pods reach their full size in from five weeks to eight months,  according to the altitude of the locality and to the amount of shade. The first indication of ripening is a slight yellowing of the whole  pod; as soon as this occurs the pods should be picked, and sorted, and the  curing process commenced. If left to ripen further the pods are prone to split  and otherwise deteriorate.

For the purpose of curing them the pods are kept in a heated room for some  days, then transferred to a cooler one and finished at ordinary temperature.  During the process, which lasts. some months, there is a loss of 70 to 80 per  cent. of weight. For details as to culture, see articles by S, J. Galbraith in  Bulletin 21, 1898, U. 8. Department of Agriculture, Division of Botany, and by  A. Franchere, Bul. Econ. Gouvt. Gen. Madagascar, vol.ii, No.2, p. 122, 1914. 

The practice of curing the beans by placing them under blankets in the sun is  still in vogue, but that of using a regulated artificial heat is more certain,  and it is. the modern method. When thoroughly cured the beans are sorted  according to length, those that have split or become otherwise defective being  separated. They are then tied into bundles, which are wrapped in sheet lead or  placed in small metallic boxes. In doing this it is essential that the bundle be  wrapped in a thin vegetable parchment paper, as chemical action occurs when the  beans come in contact With the metal. Fruits which have not been picked early enough are inferior and are  frequently cut into short pieces and sold as " cuts." If by chance the fruit  should be picked too early the quality of the resulting product is distinctly  inferior, as the fruit as first picked has no aroma, the vanillin during the  process of curing being produced from the glucoside coniferin in the interior of  the fruit.

The cultivation of vanilla has extended from Mexico and South America  throughout the tropics, so that at present, although the wild plant is abundant  in the Mexican States of Vera Cruz and Oaxaca the vanilla of the markets comes  almost exclusively from vanilleries. Holland is supplied from Java plantations;  France from Tahiti, Madagascar, Reunion, Guadeloupe, and other of her colonies.  From Mauritius and the Seychelles the product goes to London. In the markets  most of the varieties are known by the name of the country in which they are  produced. The finest of the varieties is the Mexican, although of recent years  the Bourbon beans have so improved that they almost rival it in strength and  flavor.

Of Mexican vanilla, the first quality occurs in pods from 15 to 20 cm.  long, flattened, 6 to 8 mm. in diameter, with the lower end slightly attenuated,  the upper end gradually tapering for about a quarter of the length of the pod,  usually curved and slightly twisted near the point. The color is dark brown, the  pods fairly plump, the surface ridged longitudinally, and with an incrustation  of fine crystals beginning at the ends, gradually extending; when fresh somewhat  viscid, but always roughish to the touch. For an interesting account of the Mexican vanilla plant by Charles E.  Hires, see A.J.P., 1893, 576. Cullningham states that the best quality of  Mexican beans are those plucked in January and February but that much of the  crop consists of beans plucked in October and November. Four classes of Mexican  beans occur in commerce, viz., large-fine, small-fine, zacate and basura.

Of the Mexican vanillas the most valuable variety is the papantha bean,  called ley, or vainilla mansa by the Spaniards; it consists of cylindrical,  somewhat flattened pods, six or eight inches long, three or four lines thick,  nearly straight, narrowing towards the extremities, bent at the base, shining  and dark brown externally, wrinkled longitudinally, soft and flexible, and  containing within their tough shell a soft black pulp, in which numerous minute,  black, glossy seeds are embedded. It has a peculiar, strong, agreeable odor, and  a warm, aromatic, sweetish taste. The interior ,pulp portion is most aromatic.  In it are more or less numerous, minute crystals.

Another variety, called vainilla simarona
by the Spaniards, is smaller,  of a lighter color, and less aromatic. The pods are said to be very dry and to  contain no vanillin. According to Schiede; it is yielded by a distinct species, the Vanilla sylvestris Schiede. A third  variety is the vainilla pompona of the Spaniards (boba vainilla, or platano  vainilla). In this, the pods are from 12 to 18 cm. long, from 12 to 18 mm.  broad, shaped somewhat like a plantain, almost always open, very dark brown or  nearly black, soft, viscid, and of a strong odor. Schiede states that it is the,  product of the Vanilla Pompona Schiede. The variety vainilla vezacate is said to be derived from pods  gathered long before maturity. (Nueva Farmacopea Mexicana.)

The vainilla pompona of the Spaniards is evidently the vanillons of  European commerce, which are usually from 10 to 13 cm. long and from 15 to 25  mm. in diameter, frequently sharply angled, brown to red-brown in color, usually  split open and free from efflorescence, Owing to the transverse markings by  twine with which they have been wrapped during the process of curing, the beans  have a peculiar twisted appearance. Their odor, which resembles that of  heliotrope, is due to the presence in them of heliotropin, in lieu of  vanillin.

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 C
16H + 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.