Cempedak, a funky tropical fruit you’ve probably never heard of

Congratulations to Grantham Scholar Maria Wang Mei Hua! She is celebrating the publication of her first first-author paper – which you can read here. Maria is currently studying how to make tropical crops more sustainable via spatial planning and accounting for social and environmental costs. Below she explains how work she carried out during her MS studying cempedak – a fruit which grows in her home country of Malaysia and is the focus of her paper – opened her eyes to its wonderful properties and potential.

Freshly opened cempedak and its gorgeous fleshy fruits. Photo credit: Maria Wang

Before joining the Grantham Centre, I studied the genetics of tropical fruits during my Master’s at Northwestern University and the Chicago Botanic Garden in the USA. I worked with Dr. Nyree Zerega, who studies evolutionary relationships and origins of plants in the Moraceae family, which includes mulberries, figs, as well as the culturally and economically important tropical fruits breadfruit and jackfruit.  

You may have heard of breadfruit as it played a pivotal role in the most famous mutiny in history, the Mutiny of The Bounty in 1789. The British recognized the potential for breadfruit as a food source (unfortunately, in this case, to cheaply feed slaves) so they charged Captain Bligh of HMS Bounty with the duty of transporting breadfruit plants from Tahiti to Jamaica, which, as we know did not end without incident. Today, breadfruit is grown in the Carribean and Central/South America.

Fried cempedak at a market in Thailand – Yum! Photo credit: Nyree Zerega

However, did you know that breadfruit and jackfruit are only two of nearly 70 species in the genus Artocarpus that produce edible fruit? In fact, more than a dozen Artocarpus species are already being cultivated in South and Southeast Asia. Fruits like these provide a cheap and nutritious food source because the trees can keep producing fruit for many years. Not to mention, they are better for the environment as they sequester carbon and require less water and fertilizers than conventional crops like wheat, corn and rice.

As I’m from Malaysia, I was delighted at the chance to study cempedak (Artocarpus integer), a much-loved fruit and a major local crop in Malaysia, closely related to jackfruit.

Imagine a durian crossed with an overripe jackfruit – you have a pungent stink combined with an intensely sweet aroma, oozing from an oblong fruit covered in rubbery spikes. As you cut into the cempedak, the milky white latex characteristic of the Moraceae family covers your knife. Peeling the rind open, crowning jewels of orange or yellow flesh are revealed, bursting with flavour reminiscent of durian and musky mango. Malaysians and their neighbours in Thailand and Indonesia also love eating cempedak fried, in cakes or even ice cream.

Before starting this project, I did not know many facts about cempedak and the cempedak family.

Cempedak seeds being boiled. Photo credit: Maria Wang

Firstly, I had never heard of breadfruit, even though it is grown everywhere in Malaysia (it is called buah sukun in Malay). Even my parents didn’t know about it! Heck, once I knew what it was, I spotted five breadfruit trees along the road on a 20-minute car ride in my home town! It appears that breadfruit is rarely sold commercially, but only grown in people’s backyards. Sometimes, local women will sell fried breadfruit at the market (yum!).

Secondly, neither my parents nor I had any idea that you can boil or roast the starchy seeds of cempedak and jackfruit, and they taste like chestnuts or potatoes. Imagine all the food wasted because we only eat the fleshy pulp of cempedak and jackfruit, and throw away the seeds! 

Thirdly (this blew my mind), cempedak actually has a ‘wild relative’ that grows in the forests of Malaysia. First scientifically described by a British tropical botanist E. J. H. Corner in the 1930s, it looks just like cempedak but surprisingly lacks the aroma and taste of cempedak. The different indigenous tribes of Peninsular Malaysia, collectively known as the Orang Asli, have their own names for wild cempedak, but here I will use the common (probably Malay) name of bangkong.

Unripe bangkong fruit from an Orang Asli village in Kelantan, Malaysia – it looks just like cempedak. Photo credit: Maria Wang

The bangkong fruit is harvested only for its seeds while the fleshy part is not eaten. It is an important part of the Orang Asli diet, especially when they go hunting for days in the forest. It also provides emergency food rations for rural villages. Wild crop relatives like bangkong are also really important as a genetic resource for plant breeders.

The lack of aroma and taste in the bangkong fruit led Corner to hypothesize that cempedak was domesticated from bangkong. However, another tropical botanist, Richard B. Primack, thought differently. He had found cempedak growing in the most remote forests of Sarawak, a Malaysian state on Borneo Island, and surmised that cempedak and bangkong originated separately from each other.

In our paper, we investigated the question of cempedak origins and looked at the relationship between cempedak and bangkong. We also considered other questions:

1) Are cempedak and bangkong really different entities?

Yes, cempedak is much hairier than bangkong (statistically significant)! Besides that, we found that cempedak and bangkong have distinct genetic make-ups. However, there is some mixing between them, so they are not different enough to be called different species. I’m happy to let bangkong keep its current taxonomic status as a variety (A. integer var. silvestris – which means “the cempedak” of the forest).

2) Did cempedak come from bangkong?

We used DNA sequences to map out the relationship between several cempedak and bangkong individuals, but there was no clear indication that cempedak was domesticated from bangkong (although it seems that some cempedak from Borneo are intermediate between Peninsular Malaysian cempedak and bangkong). We do see that genetic diversity is higher in bangkong than in cempedak. In short: we still don’t know.

An opened unripe bangkong fruit from the same village. Photo credit: Maria Wang

3) Are cempedak from different places also genetically different?

Cempedak from Borneo seemed to have formed their own “genetic subgroup” distinct from the genetic subgroups from Peninsular Malaysia. This is important to note because we want our germplasm collections (i.e. “gene-banks” for living plants) to conserve as much genetic diversity as we can. We are happy to report that the largest cempedak germplasm collection in Malaysia does have all the major cempedak gene pools we detected. 

4) Can we trust cempedak cultivar names?

“Cultivar” means “cultivated variety”. In our study, we recorded 25 different cultivar names, but there are many more! We found that most cempedak cultivar names are quite unreliable – unless you’re talking about durian cempedak, a funky cempedak cultivar that looks kind of like durian (but they are not actual hybrids – durian is quite distantly related from cempedak). Jackfruit-cempedak (an actual hybrid) is the most genetically inconsistent, likely because different people have tried to cross jackfruit and cempedak multiple times, but they all ended up with delicious results! 

This work would not have been possible without the help of many people, including the staff of the Forest Research Institute of Malaysia (FRIM), the Malaysian Agricultural Research and Development Institute (MARDI), the Orang Asli guides who graciously led me around in the jungle looking for bangkong, and the orchard owners and various people who let me into their backyards to sample cempedak trees.

All of these people helped me to see many new places and learned many new things – all in my own country. Isn’t it funny how we can live for so long not knowing the multitude of wonderful fruits and wild relatives that are growing not too far away?

I hope my paper will shine a light on the value of cempedak and its wild relative bangkong, as well as other neglected and forgotten fruits of the world.

Cempedak cultivars. Clockwise from top: Durian-cempedak (not related to durian! Just looks like durian); Jackfruit-cempedak hybrid; Cempedak susu, with pale cream flesh (‘susu’ means ‘milk’ in Malay); Seedless cempedak, with bright orange flesh. Photo credit: Maria Wang (top left and right) and Eli Ednie (bottom left and right)