The Chocolate Plant
Theobroma cacao

theobr


Kingdom: Plantae
Class: Magnoliopsida
Order: Malvales
Family: Sterculiaceae
Genus: Theobroma
Species: cacao

Range and Abundance:cocoa.png

The cacao plant is native to South America, and is grown in parts of Central America and Africa. Africa produces the most chocolate for export in the world. The climate there (dry, warm, plenty of sunlight) is less conducive to growth of the fungi that could kill it.


The map above displays worldwide distribution of the variety of cacao species grown throughout the globe:


Key:

Red-Criollos
Blue-Cupuacu Brown-Trinitarios Green-Forasteros Yellow-Nacional


Fun Fact: The plant was named Theobroma by Linneus, meaning "food of the gods."


Coloration and Morphology:

Wood: Light/white
Bark: Browna
Leaves:
shape - lanceolate, meaning they are lance shaped, or wider towards the middle, and thin at both ends of the leaf
color - bright green

Theobroma cacao is a small tree that typically grows to be between 4 and 8 meters tall (12 to 16 feet). Its leaves can be up to 30 cm long. They appear slightly red in early growth, but mature to a bright green color. The flowers of the chocolate plant are small, measured to be about 1 cm in width, and take on a yellow, off-white color at bloom. The ovaries of the cacao fruit terminate in a five-branched stigma, and there are approximately 50 ovules contained within each ovary. After the ovules of the plant are fertilized, they develop into cacao beans. The fruit will be ripe and ready to harvest five to eight months after planting.


Flowers of Theobroma cacao:

theo.jpg


The chocolate plant thrives in a subtropical wet to subtropical dry climate. Additionally, it can be grown in tropical wet to dry tropical rainforests. This means that most cacao plants are grown between 10 degrees North and South of the equator. As can be guessed from its obvious preference for a wet growth environment, the chocolate plant is drought intolerant. It is found in the forests of northern South America, and was held in extremely high esteem by the ancient Incas, Mayans, and Aztecs. In fact, the first cacao fruit to reach Europe was brought there by Christopher Columbus.

The plant must be cultivated under the shade produced by taller trees. For example, the banana plant can provide necessary shade to the growing cacao plant. We saw many of these banana plantations on our trip to Costa Rica, proving their potential usefulness beyond just the fruit they produce.

Cacao additionally requires a shady environment and continuously damp tropical climate. The average temperature of its natural habitat ranges from 24 to 28 degrees Celcius. Cacao is again only cultivated within the passible narrow range of 15 to 18 degress North and South of the equator. (However, 10 degrees N and S will result in optimal growth.)



Personal Experience from our Trip:

How do we harvest the plant to make chocolate?

1) Pods are cut from trees

2) Pods (containing 25 beans each on average) are cracked and beans are removed, husks are burned

2) Fermentation: so that beans cannot germinate (fruit flies often aid in this process, please see picture below)
costa.JPG
3) Drying: Beans are left for a few days to dry

3) Beans are roasted

4) Beans are shelled, and what remains is called a nib

5) Nibs are ground to cocoa liquor, which can then be processed in two different ways:


  • Pressing leads to cocoa butter, which has multiple uses
  • Cocoa cake, obtained from cocoa liquor, can be grinded up to produce cocoa powder
  • Cocoa powder can be refined into lectin and sugar, after which conching and tempering lead to the final product: CHOCOLATE



Historical Background

The Mayans discovered how to use cacao beans to make chocolate. 500 years ago, Spanish conquistadors did not like chocolate because...

1. Chocolate is bitter. The native Mayans often added chile to make it even more unappealing to those who were not used to the taste. There was nothing equivalent to the honey and sugar that sweetened foods in Europe and Asia, respectively.

2. Spain was Catholic, and the Mayans were not. Therefore, since the Spaniards did not want to accept the Mayan religion, this feeling translated to their dislike of Mayan food.

3. The Mayans' name for chocolate sounded to the Spanish like, "caca agua". Translation: Not food.

4. The Spanish did not approve of Mayan human sacrifice, and some natives put so much chile in the chocolate that it was colored red, reminding the conquistadors of human blood that could possibly be shed in sacrifice.

Once the winning combination of flavor was made (cocoa, cinammon, and brown sugar) chocolate as we know it today was born.


DISEASES:
The fungal diseases known as Black pod, Witch's Broom, and Moniliophthora Pod Rot, affect the harvest of Theobroma cacao tremendously. Each year, up to 30% of this crop is lost to such diseases, as seen on our trip to La Selva. A tree that only two years before was perfectly healthy, was discovered to be rotten presumably with fungal disease as the cause.



References:

Young et al. Floral nectaries and trichomes in relation to pollination in some species of Theobroma and Harrania. (1984). American Journal of Botany, 71(4),

Whitlock, B. and Baum, D. Phylogenetic relationships of Theobroma and Harrania based on sequences of the nuclear gene vicilin.. (n.d.). Systematic Botany, 24(2).

Lotschert, William and Gerhard Beese. Collins Guide to Tropical Plants. Grafton Street: London, 1988.