Not found in the wild. It was known in ancient Assyria, India, Egypt for several thousand years BC. Widely cultivated in Afghanistan, Iran, Pakistan, India, China, Japan, Africa (Reunion Island), USA (Pennsylvania), Mexico, USSR (Azerbaijan).
Monocotyledonous perennial plant, annually developing the aerial part from a tuber, with narrow linear leaves and 1-2 flowers. Perianth simple, sympetalous, with 6 limbs, with a long cylindrical tube; limb pale purple with darker veins. Stamens 3; ovary inferior, with a longish filiform light yellow column, divided into 3 stigmas; stigmas 3-3.5 cm long, hanging between the lobes within the flower bed, orange-red. Blooms in autumn; traditionally flowering on the plantation lasts for 2 weeks; Individual flowers bloom for only 2 days.
Only the stigmas are subject to collection, but traditionally on plantations the whole flower is plucked and then, after collection, the stigmas are plucked. Drying of the stigmas is carried out in special dryers (the resulting raw material is very hygroscopic). To obtain 1 kg of dry saffron, you need within 200,000 flowers.
The raw material (Stigmata Croci) consists of a mass of matted stigma and style threads. The stigmas are tubular in shape, expanding slightly funnel-shaped towards the top. The raw material contains both individual stigmas, and connected by 3 with the remains of the style, which should not be longer than 3 cm. Stigmas are orange-red; columns are light yellow. The smell is fragrant, the taste is spicy-bitter. A large number of columns of saffron lowers its value.
Freshly harvested saffron contains a glycoside of a carotenoid nature (protocrocin), which, when dried, forms simpler glycosides: crocin and picrocrocin. Crocin is crocetin, two carboxyls of which are esterified with the disaccharide gencibiose (6 – gluzido-glucose).
Crocin is the carrier of the specific yellow coloring matter of saffron.
Picrocrocin is a bitter substance, a glycoside that removes aldehyde safranal, the main component of the essential oil, which is found in saffron at 0.4-1.3%.
In many states, saffron finds medicinal use (for diseases of the liver, stomach, gynecological diseases, as a stimulant, antispasmodic, etc.). However, saffron is of great importance as a food coloring and aromatic spice.
Saffron is an expensive product, and therefore it is very often faked with saffron stamens, yellow ligulate marigold flowers – Calendula officinalis L., rolled into tubes and tinted, tubular safflower flowers – Carthamus tinctorius L. For fake, leached and tinted saffron, soaked in water for weighting , sugar syrup or minerals; to add shine, it is impregnated with fatty oil, etc.
The plant contains aromatic and phenolic compounds.
PLANTS CONTAINING AROMATIC AND PHENOLIC COMPOUNDS
Aromatic compounds in essential oils are represented by oxygen derivatives, of which the following are the most common.
Phenols in essential oils are represented by both individual compounds and phenol esters. The most common are the following.
PLANTS CONTAINING ESSENTIAL OILS
Essential oils are natural aromatic substances that are highly volatile and cause the specific smell of plants. For this reason, also due to their “oily” consistency and “greasy” stain on paper, which soon disappears, they received such a peculiar name.
Essential oils are not individual substances. These are complex mixtures of organic substances, the composition and number of which are different for each type of essential oil plants and can serve as a chemotaxonomic feature. The main group of substances that make up the essential oils of many plants are terpenes (more precisely, monoterpenes) and seseviterpenes, i.e., substances with an isoprenoid structure. However, in the essential oils of a number of plants, aromatic compounds may predominate, as well as numerous substances of the aliphatic series. There are plants with sulfur and nitrogen compounds in essential oils.
Essential oils in plants are mostly in a free state. However, some plants contain them in the form of glycosides and are released during enzymatic cleavage. Essential oils are formed in all parts of plants, but quantitatively they accumulate in them traditionally unequally.
They can be in a plant organism in a diffuse diffuse state (ie, emulsified or dissolved in cells) or accumulate, localize in special anatomical and morphological formations that are easily detected under a microscope. These excretory formations can be exogenous and endogenous.
Exogenous formations develop in the epidermal tissue and are:
– glandular “spots” – small-drop accumulations of essential oils immediately under the cuticle of the epidermis;
– glandular hairs – cylindrical epidermal outgrowths, consisting of a unicellular or multicellular pedicle and a head with cells that secrete essential oil;
– glands – epidermal outgrowths that have received the most
the highest specialization in the extraction and accumulation of essential oils. They have a different structure and can serve as a systematic feature. For example, in yasnotkovye (labial) 8 excretory cells are arranged in a rosette on a short stalk; in aster (composite) glandular cells have a vertical arrangement – 2 in 4 rows, etc.
Endogenous formations develop in parenchymal tissues and are:
– secretory cells – single (for example, in the air parenchyma of calamus rhizome) or form layers of such cells (for example, in valerian roots);
– receptacles – rounded cavities formed in the mesophyll of the leaf, peel of citrus fruits, in the bark and wood of a number of plants and filled with essential oil;
– tubules and passages – strongly elongated excretory formations found in the fruits of umbellate, bark and wood of a number of plants.
Essential oils accumulate in plants in all possible quantities: from hundredths and thousandths of a percent (for example, in violet flowers – 0.004%) to 20% or more (for example, in flower buds of carnations – up to 23%).
Essential oils are obtained: 1) by steam distillation; 2) extraction with some extractants; 3) enfleurage; 4) mechanically.
Steam distillation is the most common method. It is carried out in installations consisting of a double-jacketed still (in which steam circulates to prevent the still from cooling), a condenser and a receiver. Steam is fed into the cube loaded with raw materials from below through a perforated coil, entraining the essential oil. A mixture of cooled vapors of water and essential oil enters the receiver, where the mixture separates and excess water is removed through a tube at the bottom of the receiver (if oil is lighter than water) or through a drain tube at the top (if oil is heavier than water).
The extraction of essential oils from raw materials is carried out with volatile organic solvents in Soxhlet-type apparatuses or in column apparatuses. Subsequently, the raw material is lifted by the screw from the bottom up, and the extractant enters towards it. After distillation of the solvent, the residue is either pure essential oil or its mixture with other extracted substances (resins, waxes, etc.); in the latter case, additional cleaning is required.
Enfleurage is based on the fact that essential oil from raw materials (mainly from flowers) is absorbed by sorbents (solid fats, activated carbon, etc.) in special frame installations.
The mechanical method is used to extract essential oils from citrus fruits by pressing or scraping.
Although essential oils are very common in the plant world, their role for the plant organism and the reasons for their formation have not yet been reliably established. It was assumed that essential oils serve to protect plants from diseases and pests, to attract the smell of insects, which contributes to the pollination of flowers, to protect plants from excessive heating during the day and hypothermia at night, etc. Currently, most scientists believe that essential oils (or rather, their components) are actively involved in the metabolic processes of plant organisms.
Essential oils find a wide and varied application for medicinal, cosmetic, food (spices) and other chains.
Essential oils are classified according to the substances that make up their bulk, or substances that determine their medicinal and industrial value. There are the following groups (and subgroups) of components of essential oils:
Monoterpenes (terpenes), including:
1. Acyclic terpenes.
2. Monocyclic terpenes.
3. Bicyclic terpenes.
1. Acyclic sesquiterpenes.
2. Cyclic sesquiterpenes.
Aromatic and phenolic compounds.
Sulfur and nitrogen-containing compounds.
The listed compounds, especially terpenoids, in essential oils can occur in the form of numerous oxygen derivatives: alcohols, aldehydes, ketones, phenols, acids, esters, lactones, oxides, quinones. The number of terpenoids also increases due to the tendency of many of these compounds to various forms of isomerism (optical, geometric, etc.).