Black pepper

Homeland – India (Assam and Malabar). Cultivated in many tropical states – India, Sri Lanka, Indonesia, Indochina, West and South Africa, Antilles, Brazil.

Liana, clinging with aerial roots, with heart-shaped or ovate leaves; flowers are inconspicuous, collected in loose catkins; fruits – juicy spherical drupes, green at first, turning red when ripe and finally turning yellow. The fruits ripen slowly; from flowering to full maturity takes 4-6 months.

Harvest fruits unripe; they begin to collect when the lower fruits of the earring begin to turn red. Dried in the sun, and the raw material turns black, and the juicy pulp shrinks; then, by wiping and sifting, the fruits are freed from the axes of the earring. Black pepper (Fructus piperis nigri) – spherical shape, the size of a pea; the surface is wrinkled, dark gray, with a white stone inside. The smell is fragrant, the taste is strongly burning.

On a longitudinal section of the fruit of black pepper, under a magnifying glass, a narrow fruit, consisting of the epidermis, pulp (mesocarp) and hard endocarp, is visible. Inside there is one large seed, the thin shell of which has grown together with the inside of the fruit. The seed nucleus consists almost entirely of the perisperm, and only at the apex there is an insignificant remnant of the endosperm and a tiny underdeveloped embryo.

The smell of black pepper is due to essential oil (0.9-2.5%). The burning taste is caused by the alkaloid piperine (5-9%). There are gum (1-2%), fatty oil (6-12%), a lot of starch. The composition of the essential oil includes dipentene, calamus-phellandrene and sesquiterpene caryophyllene.

The piperine alkaloid is a derivative of piperidine.

Pepper is of great importance for the food industry. In medicine, it is occasionally used as a substance that stimulates appetite and promotes digestion. Included in the pills with arsenic.

White pepper (Fructus Piper is albi) is the fruit of the same plant, but harvested at full maturity. The fruits are soaked in water, then dried in the sun and the fragile pulp within the fruit is removed by rubbing. As a result, a bone remains, i.e., the endocarp is the inner layer within the carpel, consisting of stony cells. Peppers thus treated appear as greyish-white, hard, smooth balls within 5 mm in diameter. The taste and aroma are somewhat weaker than those of pepper; similar application.

The plant contains sesquiterpenes.



Acyclic (aliphatic) sesquiterpenes are considered as unsaturated compounds with 4 double bonds, which can be represented as an open bicyclic compound. From hydrocarbons farnesene is known, from oxygen derivatives – alcohols farnesol and nerolidol.

Monocyclic sesquiterpenes have one closed hydroaromatic ring and 3 double bonds located in the ring and in the aliphatic chain. Of the hydrocarbons in essential oils, bisabolene and zingiberene are the most common.




Bicyclic sesquiterpenes have 2 hydroaromatic rings and 2 double bonds (one in each ring). There are compounds like cadinene and selinene.

Bicyclic sesquiterpenes also include a large group of specific compounds known as “azulenes”, which are based on the skeleton of a highly unsaturated compound with 5 double bonds. Azulenes differ in the arrangement of functional groups.



Essential oils are natural fragrant substances that are highly volatile and cause the specific smell of plants. For this reason, also due to their “oily” consistency and “greasy” spot 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, that is, 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.

Sesquiterpenes, including:

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.).

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