SCIENTIFIC EXPLANATIONS ON TRICHOMES

WHAT ARE CANNABIS TRICHOMES ?

Trichomes are defined by Dr. Michael Backes as “small, microscopic waxy cushions of resin oil that are exuded by small glandular hairs.” They are mainly found on the surface of the floral tops, also called buds. Trichomes are not only present on the cannabis plant but on a large number of other terrestrial plants and even some algae. They present several interests for the grower and the consumer. After having seen their structure and functions in detail, we will develop the different types of trichomes and finally how they can help determine the optimal harvest window

WHAT ARE CANNABIS TRICHOMES, WHAT ARE THEIR FUNCTIONS

As defined previously, trichomes are an essential part of the plant. They contain all the molecules of interest in herbal medicine, for medical, well-being or social (recreational) use. Visually, they resemble small crystals. Phytocannabinoids as well as terpenes and essential oils will be synthesized within these glands during their maturation. These different active ingredients are responsible for the medical and psychotropic potential of the cannabis plant. They have a particularly fragile structure and can very easily break and detach from the flower. Thus, it is necessary to limit friction against the trichomes both during harvesting and during packaging in order not to risk evaporation, oxidation or even decomposition of terpenes and cannabinoids. It is on the unfertilized female flowers, and more precisely at the level of the bracts (leaf-shaped floral parts which surround the flowers and seeds of the female cannabis), that we find the greatest concentration of trichomes in comparison to fertilized female plants, male or hermaphrodite plants. Using a 40 to 100x microscope, we can observe the anatomy of a trichome in detail. It consists of a resin head connected to the stem by a so-called abscission zone. Finally, they constitute the plant's first line of defense against insects, fungi and herbivores who will be disturbed by the taste and fatty texture of the plant but also against the vagaries of the climate (drought, wind, UV rays, variations temperature)

THE DIFFERENT TYPES OF TRICHOMES

There are several variations between trichomes. Initially, we could observe differences between Indica and Sativa cannabis plants (link articles differences Indica and Sativa). In fact, the latter have finer and elongated glands. Then, the cultivation method will also have an influence on their size. Since plants grown outdoors need more protection, their trichomes are more stressed and will therefore be smaller at the end of cultivation compared to plants grown indoors. Finally, two very different types of trichomes present on the same plant were identified. The first is the non-glandular trichome, located mainly on the top and bottom of the leaves. It ensures the protective role described above. It does not contain phytocannabinoids or terpenes. The second is, conversely, the glandular trichome, which is the most interesting for the consumer. It goes through three stages of growth:

• Bulb trichome: between 15 and 30 microns in diameter, it is in its first stage of growth and contains no active ingredient
• Sessile trichome: between 25 and 100 microns in diameter
• Stemmed trichome: up to 500 microns in diameter. They develop once the first flowers have appeared on the plant. It is from this stage that the synthesis of phytocannabinoids and terpenes will begin

TRICHOMES, INDICATORS FOR HARVEST

To accurately determine the optimal harvest time, called the “harvest window,” growers will take into account the genetic characteristics of the plant, particularly the flowering period, and will carefully observe the visual appearance of the trichomes. . To assess their maturity, the density, size and color of the resin head must be taken into account. First, you must wait until the glandular trichomes have reached their stem trichome stage. Then, you have to look at their color:

• Transparent trichome: it contains no or very few terpenes. THC is already present in quantity but there is still very little CBD
• Milky trichome: this is the targeted stage of maturation. The synthesis of phytocannabinoids and terpenes is finished
• Amber trichome: has a reduced volume because the maturity stage has been passed. THC has already started to break down due to oxidation

Generally, the harvest window is therefore when there is a large majority of milky trichomes, still a few transparent trichomes and up to 30% amber trichomes. Harvesting too early or too late will change the taste of the plant but also its effects on the consumer. Depending on the desired effect, growers will prefer to harvest the plants when the trichomes are still slightly transparent, and thus have a strong psychoactive potential (high THC/CBD ratio), particularly for Indica varieties. Conversely, harvesting a plant too late with a majority of amber trichomes will tend to produce a particularly sedative effect. In question, the degradation of THC into CBN (cannabinol) which will have already started. As a reminder, this degradation is a natural and inevitable phenomenon which is accelerated by light and heat

To conclude, trichomes, although microscopic, are very valuable, both for the grower and the consumer. They will allow the plant to be harvested at the optimal time to preserve and benefit from the medical and psychotropic potential of cannabis

EXPLANATIONS ON TERPENES

Useful to understand where the different scents, flavors, tastes and effects come from.

Among the different chemical components of hemp, there are some less known than cannabinoids which are nevertheless just as interesting: terpenes. These aromatic components are responsible for the flavor and scent of hemp. However, they are not specific to hemp; they are found elsewhere in the plant kingdom, particularly in resinous plants. It is even found in certain animals and humans.

The components of terpenes

Terpenes are hydrocarbons produced by plant metabolism. Unlike terpenoids which are modified by oxidation, terpenes are formed exclusively from hydrogen and carbon. Depending on their molecular structure - in particular the number of pentacarbon units (C5) - they are distinguished into different classes (monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, tetraterpenes, polyterpenes). Just like cannabinoids, terpenes are produced by the resin glands of hemp: the trichomes.

Unable to move to protect and reproduce, plants have developed survival strategies based primarily on chemistry. Terpenes are at the heart of these strategies: they function to push the predators of the plant while attracting pollinators insects that ensure its reproduction. To grow unhindered, some plants develop terpenes that attract the predators of the surrounding plants. It is a true chemical war that takes place in nature and the terpenes are the weapons. They are also essential for the development of the plant, for the manufacture of pigments, sterols and hormones as well as cannabinoids.

Terpenes and hemp

Terpenes influence the scent, flavor and also color of hemp. Each strain has a specific terpene profile with different ratios and concentrations of different terpenes. The possible combinations are almost endless. The terpene profile varies even within the same variety depending on the growing conditions (climate, quality of soil and fertilizer) and the degree of maturation of the plants at harvest.

Terpenes participate in the identity of the plant, not only in terms of the sensitive aspect but also in terms of the physiological effects. It seems that they are partly responsible for the characteristic effects of each strain. Indeed, they can influence, directly or indirectly, the way in which cannabinoids bind to receptors. Thus, two varieties with the same THC/CBD ratio often have different effects. This synergy of the different chemical components of hemp is called the “entourage effect”.

What use for terpenes ?

Terpenes are the basis of aromatherapy, they are the main components of essential oils. They do not have psychoactive effects but are nevertheless biologically active. Some can, for example, help regulate mood or sleep. Others have anti-inflammatory or analgesic properties. That said, scientific research into the therapeutic properties of terpenes remains marginal for the moment. In industry, terpenes are mainly used to restore the taste or smell of hemp in a variety of everyday consumer goods: perfumes, cosmetics, soaps, candles, confectionery, cannabis-flavored drinks, etc. Among the most common and widely used terpenes are:

• Myrcene : this is the terpene most commonly produced by hemp. In some varieties it can make up 50% of the total terpene content. It contributes to the sedative effect of many indicas. It is also found in hops, eucalyptus, wild thyme, lemongrass and mango. Its smell is “earthy” and musky with overtones similar to clove. It has analgesic and anti-inflammatory properties and maximizes the body's absorption of cannabinoids by increasing CB1 receptor saturation levels.
• Pinene as his name suggests, this terpene has a pine scent; we find him in the pine needles. It is sometimes used as local antiseptic or as expectorant. Through chemical reactions, it can be transformed into other terpenes such as lemonene.
• Lemonene : also present in citrus fruit, this terpene is responsible for the color of the lemon and orange (the color difference is due to a concentration difference). Hemp varieties that contain many will have a lemony odor. Plants use it as insecticide. In man, he is renowned for “to put in good mood.”.
• Linalol : also present in lavender, this terpene has relaxing and anaesthetic virtues ideal for sleep.
• Beta-caryophyllene : also present in black pepper or cinnamon leaves, this terpene protects the lining of the digestive tract and relieves neuropathic and chronic pain.
• The list is still long, there are more than 200 terpenes in the cannabis plant (not counting their numerous chemical variations).