This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The saffron crocus, Crocus sativus, Linne (N.O. Irideoe), has been cultivated for so many centuries that its native country is no longer known. It was well known to the Greeks and Romans, who used it as a medicine, as a dye, and as a flavouring agent. It was cultivated in Spain in the tenth century, and was subsequently introduced into France and England; it is, however, no longer grown in this country.
At the present time Spain produces the bulk of European saffron. On the plains towards the east and south-east the saffron crocus is grown extensively, the saffron being exported from Valencia and Alicante. A little is also produced in.France, near Pithiviers, about fifty miles south of Paris, as well as in Greece and Persia.
The plant produces in the autumn usually one or two pale purplish violet flowers, not unlike the ordinary garden crocus. The long pale yellow style terminates in three deep red elongated stigmas (fig. 47 A), which protrude from the flower and are pendulous. The whole flower is collected in the morning, spread out on mats to dry partially; then the stigmas are removed and dried in sieves over a low fire. This forms the hay saffron of commerce, which must necessarily be a valuable drug, since it takes about 750 fully developed stigmas to make one gramme of saffron.
Hay saffron forms a loosely matted mass of dark, reddish brown, flattened stigmas with a strong, characteristic odour and bitterish taste. When fresh it is unctuous to the touch and glossy, but after keeping, it becomes dull and brittle.
Thrown on the surface of water the dry stigmas rapidly expand, and their form can be easily studied. At the same time the water surrounding them slowly assumes a deep yellow colour. Each stigma is about 25 mm. in length, and has the shape of a long tube, narrow at the base, where it joins the style, but broadening towards the upper extremity, where it is slit on the inner side. The mouth of the tube is irregularly notched. The stigmas are either single or attached in threes to a short portion of the pale yellow style.
The characteristic shape of the saffron stigmas is of the greatest service in the detection of adulteration; the student should therefore soak a little saffron in water and examine it carefully with a lens.
Saffron contains a trace of volatile oil, a bitter principle, picrocrocin, and red colouring matter, polychroite (also called crocin).
The volatile oil consists principally of a terpene, probably associated with a small quantity of an oxygenated aromatic constituent.
Fig. 47. - A, three stigmas of Saffron with a portion of the style, magnified 2 diam. B, Calendula floret, magnified 1½ diam. C, Safflower floret, magnified 1½ diam. (Vogl).
Picrocrocin is a colourless crystalline glucoside yielding by hydrolysis crocose (a reducing sugar) and a terpene with an odour recalling saffron.
Polychroite is closely related to carotin and like carotin colours concentrated sulphuric acid deep blue. It has been obtained as a ruby-red, amorphous, glucosidal substance yielding by hydrolysis a new red colouring matter, crocetin (also called crocin), volatile oil (?) and sugar. Crocetin is acid and forms crystalline salts with ammonia, brucine, etc. Saffron apparently contains a second red colouring matter, insoluble in water but soluble in alcohol.
The high price of the drug has naturally been, even during the time of Dioscorides and Pliny, a great inducement to adulteration. This has been affected in one (or more) of the following three ways:
(i) By substituting some substance for the saffron stigmas, (ii) By recolouring exhausted saffron, (iii) By artificially increasing the weight of genuine saffron.
(i) Under this heading the following may be mentioned as of frequent occurrence, but numerous others have from time to time been observed: the long, pale coloured styles of the saffron crocus, or the stamens, or portions of the perianth of the same; calendula florets coloured with methyl-orange and sold under the names of feminell or Chinese saffower; the florets of the safflower (Carthamus tinctorius, Linne), an Indian composite plant, largely used as a dye and often found in the cake saffron of commerce; the slender stems and roots of monocotyledonous plants.
(ii) Artificial coloration has been effected with aniline dyes, logwood, Brazil wood, the salts of dinitrocresylic acid (Victoria yellow, Victoria orange), etc. Genuine saffron, when thrown on to the surface of water, should slowly surround itself with a circle of yellow (not orange yellow, red or pink) liquid; it should yield but little colour to ether or petroleum spirit, in which many artificial colours are readily soluble. Animal charcoal almost instantaneously decolorises an infusion of saffron, whereas aniline colours are much less readily removed. An infusion of 0.1 gm. of the suspected sample in 100 c.c. of water should agree with a similar infusion of genuine saffron, both in depth and tint of colour. A solution of chromic acid may also be used as a standard for comparison; O'l gm. of saffron should impart as deep a colour to 50 c.c. of water as 0.275 gm. of chromic anhydride.
(iii) Saffron may be artificially weighted in a variety of ways. Vegetable or mineral oil, which, in addition to increasing the weight, improves the appearance, may be detected by pressing the saffron between thin sheets of paper; a greasy stain indicates the presence of oil. Saffron should not contain more than 12.5 per cent, of moisture or yield more than 7 per cent, of ash. The presence of glycerin, ammonium nitrate, and of other substances soluble in water, but leaving no ash when incinerated, may be detected by ascertaining the amount of aqueous extract yielded by the saffron; it should not exceed 51 per cent.
Cape Saffron, now seldom imported, consists of the flowers of a Scrophulariaceous shrub, Lyperia atropurpurea, Bentham, a native of South Africa; it contains a yellow colouring matter, but could scarcely be mistaken for saffron.
Cake saffron ('croci placentae,' 'crocus in placenta') commonly consists of safflower florets made into cakes with an adhesive sugary substance. The structure of the florets is easily seen when a little of the drug is soaked in water
Although chiefly employed as a colouring agent, saffron has been regarded as stimulant, antispasmodic, and emmenagogue.