Jackfruit Facts, Cacao Trees, and a Replacement for Cocoa
A Useful and Potentially Important Plant
The jackfruit tree is a tropical plant in the same family as figs, mulberries, and breadfruit. The tree's fruit is notable for its huge size and its many culinary uses. Researchers have discovered that the roasted seeds have an aroma and taste resembling that of cocoa. This discovery could be very important for chocolate lovers. The cocoa that gives chocolate its flavour comes from the seeds of cacao trees. The population of these trees is in trouble due to a variety of factors. Jackfruit seed powder might be at least a partial replacement for cocoa.
The name "jackfruit" is thought have arisen from the Portuguese name for the fruit, which is jaca. This word is in turn thought to have come from the word chakka, the name of the fruit in the Malayalam language of Kerala. Kerala is a state in India. In March 2018, the jackfruit was declared the official fruit of the state.
Features of Jackfruit Trees
The jackfruit tree has the scientific name Artocarpus heterophyllus and belongs to the Moraceae family. It's endemic to India but is grown as a cultivated plant in many tropical areas. The tree is evergreen. It may reach a height of seventy feet and occasionally reaches ninety feet, but it's generally a little shorter. The leaves are oval or shaped like an ellipse and have a glossy surface.
The tiny flowers are borne in clusters. The fruit is an aggregate structure made from hundreds or even thousands of flowers. The plant is classified as cauliflorous because it bears fruits on its trunk as well as its main branches. Each fruit is attached to the tree by a short stem.
The fruit is green or yellow when ripe and can reach a huge size. It's the largest fruit of any tree in the world. According to various reports, its maximum weight when mature ranges from 70 pounds to as much as 120 pounds. The rind is covered by knobs. There are generally at least a hundred seeds in a fruit and often considerably more.
An aril is an extra seed covering that frequently develops from the stalk of the seed. It's often fleshy and brightly coloured.
Culinary Uses of the Plant
Before it's opened, the ripe fruit has an unpleasant aroma. It's often said to smell like decaying onions. On the other hand, the ripe flesh or pulp inside the rind has a pleasant scent that resembles that of a pineapple. It tastes sweet and has a banana-like flavour. The flesh is used to make desserts such as custard, ice cream, purée for filling pastry, and cakes. It's also added to shaved ice to make a dessert. It's sometimes added to dishes containing rice or is fried to make a snack.
The unripe flesh is also eaten and has a meaty texture, though it has a fairly neutral taste. It’s mixed with meat in various dishes, including curries, or even used instead of meat. According to the USDA (United States Department of Agriculture), one cup of sliced jackfruit contains 2.4 grams protein. The fruit has a much lower protein content than meat or even beans or lentils, but its texture makes it appealing for vegan dishes. The taste is improved as the fruit absorbs spices and sauces.
A vegan version of "pulled pork" made from jackfruit seems to be popular in North America and the UK at the moment. The seeds of the plant are sometimes mixed with lentils, vegetables, and spices, including turmeric, to make a curry.
Jackfruit seeds are often boiled, roasted, or baked before being eaten. In some countries they are considered unimportant, however, and are discarded. They might be a valuable resource in the future.
The cacao tree has the scientific name Theobroma cacao and belongs to the family Malvaceae. It's endemic to Mexico, Central America, and South America and is cultivated in several tropical countries in other parts of the world. It's a smaller plant than the jackfruit and reaches a maximum height of around twenty-five feet. The tree is sometimes described as "spindly". Cacao trees are planted under taller trees of the rainforest and are evergreen.
The leaves of the cacao plant are dark green, glossy, and oval or elliptical in shape. The flowers are small and pale yellow to pink in colour. They are borne in clusters. The flowers are pollinated by midges (small flies of various species). According to Kew Science, only around 5% of the flowers receive enough pollen to produce fruit.
The tree is completely cauliferous. All of the flowers and fruits are attached to the trunk. The fruit is red or brown in colour when ripe and is technically a berry, though it's referred to as a cocoa pod. It contains thirty to forty seeds, which have a lavender to purple colour. When the seeds are fermented they develop a red brown colour and are known as cocoa beans.
Cacao Trees and Cocoa in Trouble
The cacao tree population is decreasing, which is bad news for chocolate lovers. The reason for the decrease seems to be multifactorial. The plant is being damaged by pests, fungi, and viruses. In addition, it's susceptible to climate change.
A major culprit in the tree's problem is a virus that is transmitted by insects known as mealybugs. The virus is called cacao (or cocoa) swollen-shoot virus, or CSSV. Mealybugs are small creatures belonging to a group known as scale insects. They are often parasites of plants. The insects feed on the sap of the cacao trees. Sap is a watery liquid containing sugars. It's found in the phloem vessels that transport food made by photosynthesis. CSSV is most common in West Africa and also occurs in Sri Lanka.
Several strains of the CSSV virus exist. The ones that cause the most serious effects can kill a cocoa tree in two to three years. Symptoms vary but often include:
- reddening of the veins of young leaves, which disappears later
- the appearance of yellow lines along the main veins of mature leaves
- yellow flecking and mottling of leaves
- swelling of stems and roots
- unusual pods with a spherical shape
Preventing the Spread of the Disease
According to the World Agroforestry Centre, once a tree is infected by the CSSV virus, the infection can't be cured. Management of the disease in a population is therefore very important. Protection techniques include:
- removal of diseased trees
- sanitization of potentially contaminated equipment, hands, footwear, and clothing
- the use of rubber boots that can be easily cleaned
- avoiding deliberate transfer of plant material from one farm to another
- breeding of cacao tree varieties that are more resistant or completely tolerant to the virus
Farmers are being asked to avoid transferring plant material from one farm to another even when the plant looks healthy. Symptoms of the disease may not appear for some time. Future techniques to protect the plants may include genetic manipulation to create resistance.
The plant pathologist in the video above says that the CSSV virus is actually a complex of related viruses. She also says that some cacao tree farmers are switching to other crops due to the problems with the trees.
The Use of Pesticides
Pesticides are used in the cocoa industry, but not as much as might be expected. Safety issues for farmers are a serious concern. Cacao trees are generally grown on family farms instead of in large plantations. Millions of these farms exist in order to support the world's demand for chocolate.
Providing safety training for all of the cacao tree farmers and teaching all of them about the most effective way to use a pesticide is difficult. In some cases, the farmers are illiterate due to lack of education caused by poverty. They are therefore unable to decipher written instructions about pesticide use. The cocoa industry involves social problems as well as business ones.
Jackfruit Seeds as a Replacement for Cocoa
Some people feel that jackfruits are underutilized and are investigating new uses for them. In areas where the fruits are abundant, many are ignored or discarded. They could be an untapped resource both where they are currently grown and in other countries.
Jackfruit seeds contain some of the chemicals that give cocoa beans their aroma, including 3-methylbutanal, 2,3-diethyl-5-methylpyrazine, and 2-phenylethyl acetate. In 2017, a team of scientists from Brazil and the UK published the results of an interesting experiment. They found that a long fermentation (twelve days versus five to eight for cacao seeds) followed by roasting at a moderate temperature creates an aroma closest to chocolate in the seeds.
Consumers will probably want a chocolate flavour as well as a chocolate aroma in a cocoa substitute. A 2018 report from Brazilian scientists says that jackfruit seed powder can replace 50% to 75% of the cocoa in a cappuccino without changing the aroma or the flavour of the drink. The research into the cocoa substitute seems to be in its infancy but may have interesting possibilities.
A cappuccino is a mixture of espresso, steamed milk, and milk foam. It's quite similar to a latte but has less milk and more foam. Cappuccinos often have chocolate powder on their surface.
Preparing for the Future
Hopefully conditions will improve for the world's cacao trees. The use of jackfruit seeds might be very useful while the cacao population is recovering or in case the use of cacao trees for seed production becomes an unsustainable practice. It will be interesting to see whether the taste of jackfruit seed powder is acceptable for consumers when used more extensively than in a topping for a cappuccino.
Chocolate is a delicious treat and cocoa is believed to have some health benefits. It's unknown whether jackfruit seeds have the same benefits for health. It would be a shame to completely lose the cocoa bean crop and any advantages that it may offer. The effort to protect and save cacao trees is important.
Jackfruit declared the official fruit of Kerala from The Hindu Business Line
Information about Artocarpus heterophyllus from the Missouri Botanical Garden
An exotic fruit from Business Insider
Nutrients in raw jackfruit from the United States Department of Agriculture
Information about Theobroma cacao from Kew Science (Royal Botanical Gardens)
Cocoa bean information from the World Agroforestry Centre
Cacao trees are dying from the phys.org news service
Facts about cocoa swollen shoot virus disease from the World Agroforestry Centre
A potential cocoa substitute from Confectionary News
Jackfruit seeds could help looming ease cocoa bean shortage from the American Chemical Society
Cappuccino made with jackfruit seed from the EurekAlert news service
© 2018 Linda Crampton