Give chocolate a fighting chance

Maciej Gorzelinski/EyeEm/Getty

READING will keep its secrets safe. Some might describe this town, 60 kilometers west of London, as nondescript. Exotic is certainly not the word. But hidden within a walled garden in a field on the south side of town is a special and unique destination. If it weren’t for what was going on here in the giant white tent, the chocolate would hit the stony road – nothing like marshmallows. This is the International Cocoa Quarantine Center. Find all your holiday reading here

Chocolate is the most popular sweet in the world. Globally, we eat 7 million tonnes of chocolate a year, and demand is on the rise as consumers in Asia also love the taste of chocolate. However, supply is never guaranteed. Most of the world’s commercial cocoa plants originate from just a few clones created in the 1940s, which have so far proven productive enough to meet demand. But this leads to a dangerous lack of genetic diversity, leaving cocoa vulnerable to the many pests and diseases that love it just like we do. Approximately 30 to 40 percent of crops are lost to disease each year, and there are concerns that climate change will worsen the problem. Efforts to breed new varieties of cocoa that are more productive, hardy and pest-resistant mean sending specimens around the world, which risks spreading disease and making matters worse. That is why, since 1985, the majority of cocoa samples transported to distant regions have made his two-year pit stop. “Today, Reading is the epicenter of the international cocoa movement,” says Andrew Daymond with some pride. He is a plant physiologist at the University of Reading and is in charge of cocoa quarantine. Once inside the tent, I am transported to the tropics. A wall of heat and humidity hit me, along with an impressive sight of hundreds of lush, green, two-meter-tall plants. Some had large orange or red pods hanging from their trunks. Daymond led me down a path of trees, stopping to snip a wrinkled yellow pod. Slice it open to reveal a white, slimy pulp with fatty brown seeds inside. The seeds are bitter and have only a slight chocolate taste. It is only after the seeds and pulp are fermented and the seeds are dried and roasted that the characteristic crunchy flavor begins to appear. “Why do we read?” I ask. It is a different world from the tropical forests of South America where cacao grows naturally. That’s exactly what’s important, Daymond says. Even if the pathogen were to escape, it would not survive long in Britain’s warm climate, and there are no crops in its native habitat to infect. In quarantine, Daymond and his team are keeping an eye out for fungal diseases that cause pods to rot, such as witch’s broom and the festive-sounding frostypod, both of which spread easily. In the 1990s, witch’s broom decimated cocoa production in the Brazilian state of Bahia after spores were introduced from the Amazon region, perhaps intentionally. Bahia’s production plummeted by 75%. So far, neither disease has reached West Africa. West Africa currently grows most of the world’s cocoa. They have various problems there. The insect-borne disease bud swollen virus can kill cocoa trees within a few years, and the bush beetle feeds on the pods, reducing yields by up to 40 percent. Yuri Cortes/AFP/Getty Images The cocoa samples arrive in Redding in the form of budwood (short sticks with many actively budding buds). Approximately 30 new varieties are introduced each year, including wild plants from rainforest expeditions. Upon arrival, samples are inspected for obvious signs of insect stowaway. The bud is then grafted onto a seedling to establish the mother plant. To check for any less obvious problems, buds from the mother plant are also grafted onto seedlings of an “indicator” plant, a type of cacao that exhibits more pronounced disease symptoms than other plants. If a virus or other disease is present in the incoming sample, symptoms will eventually develop. After two years, the research team is confident that the dormant virus will emerge and the plant will be deemed safe. Genetic tests being developed at the University of Reading could offer a way to speed up the isolation process, but Daymond says he is still not sure if these tests can detect all viruses. . Once the cacao trees are proven to be disease-free, cuttings are sent to researchers around the world. One of them is Wilbert Phillips Mora, a cocoa disease expert and head of the breeding program at Costa Rica’s Center for Advanced Education in Tropical Agriculture (CATIE). For decades, he has painstakingly mixed promising strains to create hybrids that are screened for disease resistance. “We are refreshing the cocoa blood,” says Phillips Mora. His CATIE R6, one of the new varieties he developed, not only shows remarkable resistance to frosty pods, but also significantly increases productivity. The chocolate decorating the cake was honored in 2009 at the International Cocoa Awards for its taste and aroma. quite a pile of beans New varieties such as CATIE R6 are sent to researchers in other countries to cross with indigenous crops and deploy to farmers. Many plantations, particularly in West Africa, are reaching the end of their productive life. This new blood is desperately needed.. The quarantine greenhouse is the size of four tennis courts, and most of it is already filled with all-cleared plants (400 varieties). Plants still in quarantine will be kept separately. Has anyone made chocolate from the Redding crop, preferably ask Daymond. “That’s not something we tried,” he says. “You need heaps of beans to properly ferment cocoa beans, and we don’t have a lot of pods available here.” Regardless, I decided to give it a try when I got home. I placed the contents of the single cacao pod Daymond gave me in the most tropical environment I could find, next to a hot water tank. First, the pulp must be fermented into an alcoholic liquid to break down the astringent compounds contained in the seeds. The seeds are then dried and roasted in the oven. easy. Or not, after all. A few days later, I noticed that there were a few moldy black beans in the bag, and it had a not-so-appetizing aroma. Leave the chocolate making to the experts and enjoy the exotic flavors of Redding in every bite. This article was printed under the heading “Away from Chalk”.

Source: www.newscientist.com