Coffee, an economy in a cup
Who discovered the magical brew?
The discovery of coffee is still under debate. Some argue it was a 9th century goat herder from Ethiopia that saw how excited his goats became after eating the berries. Others say Sheikh Omar discovered coffee during his banishment to the desert in Yemen. He chewed the berries, but they were bitter. So, he decided to roast them, this however, led to them hardening. So, he then decided to boil them so they could soften. This led to the discovery of the aromatic brown liquid. When it first arrived in Europe, coffee was known as ‘Arabian wine’.
The perfect blend
There are several shrubs of the genus Coffea that are used for coffee production. The two most popular commercial species are Coffea. canephora and Coffea. arabica. The C. arabica is self-pollinating, therefore, its seedlings are very similar to its parent tree. C. canephora on the other hand does not self-pollinate, resulting in seedlings that are rather unique. Coffea canephora, more commonly known as ‘Robusta’ coffee, is often bitter and fuller bodied compared to ‘Arabica’ coffee (C. arabica). Robusta strains also contain about 40–50% more caffeine than Arabica. Hence, about three-quarters of coffee cultivated globally is Arabica.
A benefit of Robusta is that it is less susceptible to diseases than Arabica and can be cultivated in lower altitudes and warmer climates where Arabica will not thrive. Blend these two coffees together and a full-bodied aromatic coffee blend emerges. In fact, most high-end coffees are actually a blend of these two coffee varieties from similar or different origins such as Ethiopia and Columbia.
Global sales approximate 166 million 60 kg bags of coffee in the 2020/21 economic year. That is an astonishing 10 million tons of coffee. So, it begs the question: Can our economy run without coffee?
Plant tissue culture’s role in the coffee industry
Climate change and globalization have brought with them challenges to the coffee industry. As global warming increases, the impact on natural climates is increasing. The regions in which coffee trees are currently grown, are likely to experience harsher and more frequent droughts. Globalization has made the spread of parasites and diseases easier as well. Diseases such as coffee leaf rust, collar rot, berry blotch, etc. can significantly impact coffee production. It takes three to four years to produce coffee berries using traditional propagation methods. As such diseases can significantly detoriate the quality and quantity of the coffee berries being produced. Luckily, modern biotechnology is able to (partially) combat these challenges.
Since the 1990s, somatic embryogenesis (SE) has been used to propagate favourable varieties of coffee, such as the Arabica F1 hybrid and various Robusta varieties. For more information on SE, you can read our article, ‘Somatic embryogenesis for plant tissue culture’. This is the most popular plant tissue culture (PTC) technique in coffee production.
Somatic embryogenesis has made it possible to multiply many coffee trees, producing clones that are adapted to the challenges of modern coffee production. For instance, coffee trees usually need to be grown in shaded polycultures where taller trees can provide shade for the coffee. However, this negatively impacts production efficiency. With the use of plant tissue culture, coffee trees that perform well under full light can also be multiplied and planted as monocultures.
SE has also been used to produce coffee trees that are drought and/or pest resistant. These adaptations to the crop help to reduce losses and make the production of coffee more secure. Additionally, economic and environmental costs are reduced as there is less need for coffee plants to be watered during droughts or for pesticides to be used in high quantities. This significantly reduces the cost of production.
The coffee crisis of 2012 and the need for pest resistant coffee trees
For many coffee lovers 2012 was a warning. During this year diseases caused a production decrease of 10% in Central American coffee plantations. Although 10% does not seem like much, it had consequences in the following years. In the next two years, coffee production decreased by 20% in 2013-14 compared to 2011-12 as a result. This shows the seriousness of secondary loss due to diseases. Coffee plantations are under a tremendous threat of secondary losses due to diseases, as these long standing crops are not replaced annually. This is why multiplication through plant tissue culture of disease resistant coffee plants is vitally important to the industry.
Growing caffeine-free coffee trees through plant tissue culture
Decaffeinated coffee represents around 10% of the global coffee trade. There are many Coffea species that have little to no caffeine in their beans. These species do not have the flavor and aromatic characteristics like Robusta and Arabica. Even though some Arabica plants are caffeine-free they only represent around 1% of the population. Therefore, a process called the Swiss Water Decaf Process is still mostly employed to remove caffeine and create decaf coffee. This process uses hot water and activated charcoal to remove the caffeine. Unfortunately, the caffeine can not be recycled. Plant tissue culture is currently used for multiplying caffeine-free Arabica plants. Making decaf coffee plantations a possibility for the future.
A coffee a day keeps the procrastination at bay and PTC is helping make the world’s most popular drink tastier and cheaper.
By Christos Tripodis | 1-February-2022
About the author
Christos Tripodis was raised in the windy city of Port Elizabeth, South Africa. This southern coastal city is now known as Gqebreha and is the Bottlenose Dolphin Capital of the World. During his time at Nelson Mandela University, Christos focused on physics and biology. Eventually graduating with a BSc Honours in Botany with a focus in ecophysiology and phytoremediation. Currently, Christos is using his communication skills and understanding of botany as an Inside Sales Representative at Lab Associates B.V. When he is not reading or writing you can find him botanizing or in the ocean. His other passions include cooking, martial arts, and languages.
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