Which chocolate do you prefer? Dark, milky, white? Have you ever thought that there is all that in chocolate to make it so pleasing to us? Do you know which are the closest plant relatives of the cocoa tree, the tree from which chocolate is made?

The Spanish conquerors of Latin America found the natives of this area enjoying a drink made from the beans of the cocoa plant. The Mayans made chocolate as a drink with water and added chili peppers, and they got the foam on the drink by pouring the drink from one container to another.

The Spaniards liked the smell of the drink, but not the taste because they found it bitter. That's why they thought of adding sugar to the drink and – the rest is history. The Olmecs, Mayans and Aztecs knew about chocolate, and the Aztec deity Quetzalcoatl is associated with chocolate. According to Aztec legend, this deity gave chocolate to humans.

Theobroma cacao is the scientific name of the cacao plant that produces the fruits from which cocoa is made. The name “theobroma” itself comes from the ancient Greek word θεός (theos), meaning “god, deity”, and βρῶμα (broma), meaning “food”. So, cocoa and chocolate are “food of the gods”, which is quite close to the truth, if we consider the fact that chocolate makes us happier because it causes increased secretion of oxytocin, the neurotransmitter of happiness. Cocoa is a plant native to the tropics of Central and South America, but it is also grown in Africa, especially in Tanzania, Ghana, Ivory Coast and Nigeria, and cocoa production in these countries exceeds production in the regions where cocoa originates.

There are less well-known relatives of this woody plant are cupuaçu (kupuasu, Theobroma grandiflorum) and mocambo (Theobroma bicolor), and both of these species produce butters rich in saturated and unsaturated fatty acids, similar to cocoa butter. Theobroma bicolor is the species that the ancient Aztecs cultivated alongside Theobroma cacao to produce “Aztec” chocolate.

One of the interesting things about the cacao tree is that its flowers grow directly on the tree, and not, as we usually expect, on stalks on the branches. This phenomenon is called cauliflory . The plant itself belongs to the mallow family (Malvaceae) and its closest relatives are white, black and musk mallows, hibiscus and okra!. The fruit is a type of pod that contains cocoa beans. These grains were used as currency in pre-Columbian civilizations.

Chocolate is a solid mixture consisting of cocoa, cocoa butter (“cocoa parts”), milk, sugar, emulsifiers such as lecithin and possibly other components. High-value dark chocolates have a lower proportion of milk and sugar, while the amount of cocoa parts ranges from 60 to even over 90%, although some of the most common dark chocolates on the market are those with 72%, 75% and 85% cocoa parts. Milk chocolate has only about 30% cocoa parts.

Cocoa tree cells have 10 pairs of chromosomes, or 20 chromosomes, and the genome has 28,798 genes, which is more than the number of genes in the human genome (about 23,000). Many of these genes encode proteins necessary for the synthesis of a number of non-protein compounds, including terpenes, flavonoids, theobromine and a number of other substances such as polyphenols. Theobromine itself belongs to alkaloids, and caffeine is the closest to it in composition.

Theobromide is a heterocycle, which means that it has not only carbon atoms, but also nitrogen atoms in the ring structure. Both caffeine and theobromine belong to xanthines, a type of alkaloids that are derivatives of xanthine acid, and essentially belong to purine bases, close to adenine and guanine, compounds that represent the “letters” of the genetic code. Theobromine stimulates the heartbeat, but is also responsible for the aphrodisiac properties of chocolate .

It is poisonous for those animals that metabolize this substance more slowly and with difficulty, such as dogs and cats, with the difference that cats rarely have problems with theobromine poisoning because they do not have sweet receptors and therefore are not “craving” chocolate, unlike dogs, who like it. sweet So never, ever give your pets chocolate!

Chocolate also contains phenylethylamine, which is largely responsible for that good feeling after eating chocolate. Phenylethylamine has been nicknamed the ‘chocolate amphetamine’. High levels of this neurotransmitter help promote feelings of attraction and arousal. Phenylethylamine works by stimulating the brain's pleasure centers and reaches its peak during… orgasm. However, when we ingest phenethylamine, our bodies break it down before it reaches our brain, so it doesn't really affect our mood in particular. But it still feels good to eat chocolate. I guess some of those molecules reach where they need to be.

Chocolate contains anandamide , a substance that acts as a neurotransmitter in our body. Anandamide or N-arachidonoyl thanolamine (AEA) is an endogenous cannabinoid naturally present in the human brain that induces feelings of happiness. The name of the compound comes from the word ananda , which means “bliss” in Sanskrit, and the suffix amide.

The effects of anandamide are mediated by CB1 cannabinoid receptors in the CNS and CB2 receptors in the peripheral nervous system. The free endogenous anandamide itself, created in the metabolism of arachidonic acid, has a very short half-life: it is affected by the enzyme FAAH (fatty acid amide hydrolase).

Anandamide is generally associated with happiness, and there is a possibility that it works in the therapy of depression and anxiety. By that we mean first of all things that lead to an increase in endogenous anandamide, and not exactly chocolate therapy. For example, paracetamol works exactly like this, and this partly explains the analgesic effect of paracetamol.

0.5 μg of anandamide per gram of cocoa was found in cocoa , which is very interesting and perhaps the effect of this fatty acid amide can explain the phenomenon of “chocolate cravings” and feelings of happiness and satisfaction after eating chocolate.

The ingredients of cocoa butter also contribute a lot to the aroma of chocolate, because butter, otherwise a mixture of different fatty acids, melts at our body temperature and thus actually helps the aromatic substances to come into contact with the taste receptors. Also, some of these fatty acids themselves contribute to the unique flavor of chocolate. Butter consists mainly of palmitic, stearic and oleic acids and some linoleic, arachidic and some other fatty acids in small percentages.

Cocoa butter is obtained after fermentation and roasting of cocoa beans. The change in the ratio of saturated and unsaturated fatty acids is reflected in the melting point of chocolate: a higher percentage of unsaturated fatty acids in the composition will also affect the lowering of the melting point of chocolate. Better quality chocolates do not melt so easily: the amount of saturated fatty acids will raise the melting point and these chocolates will melt only in the mouth, which is a desirable feature.

On average, a bar of chocolate contains 350-540 kcal, depending on the type of chocolate. And now I leave you to enjoy a chocolate treat sensibly.



Jelena Kalinić, MA in comparative literature and graduate biologist, science journalist and science communicator, has a WHO infodemic manager certificate and Health metrics Study design & Evidence based medicine training. Winner of the 2020 EurekaAlert (AAAS) Fellowship for Science Journalists. Short-runner, second place in the selection for European Science journalist of the year for 2022.