Rambutan Seeds | Toxic when raw, edible when roasted or boiled

Warning to the public! The following may stop you from eating the very delectable rambutan fruit forever! The yummy and juicy flesh is perfectly safe but the outside peels and inner seeds are of different story. It contain poisonous substance.

Seed testa have nephelium saponin and tannin. The compounds tannins and saponin have dual sided reputation, usefulness in medicine and other industries and the dangers of being toxic. Tannin is one of the healthy components of wine. It is known to have antiviral, antibacterial, antiparasitic, anti-inflammatory and antiulcer effect. Plant saponin is commonly used as fish poison and have some medicinal benefits as well.

No recorded deaths due to eating of rambutan seeds and peels.

Bitter and toxic when raw but edible and safe when roasted. I tried biting a seed before knowing the fact that it is poisonous. I only sensed very slight bitterness. I chewed raw peanut too and never detected any noticeable difference. I have never tried roasting it yet.

Another way to cook the seeds is by removing the seed coat or testa, boiling in water until soft, then boiling in syrup to make sweet.

Contains tallow similar cocoa butter. About more than 37% of seed is tallow. Tallow is gathered by cold pressing method. Useful for making soap and candles. Maybe a rambutan seed chocolate is possible. Not sure! I hope I can gather enough seeds to do a little crazy experiment.

Seeds are known to lower blood sugar level, expel intestinal worms and tone muscles.

The fruit skin is also known to have toxic saponin. Need to dig further details about…

Rambutan seed composition by  Augustin, M.A. Chua, B.C. 1988
37.1-38.9% crude fat – pet ether extract
2.8-6.6 crude fiber
2.6-2.9 dry ash on dry weight basis

Seeds are not poisonous according to this recent research..
Toxicity studies on rambutan (Nephelium lappaceum) seed fat and oil extracts using acute oral, dermal and irritation assays

Jirawat Eiamwat, Sareeya Reungpatthanaphong, Saranya Laovitthayanggoon, Tuanta Sematong, Paramee Pengprecha, Benjaporn Tiensong, Patthanant Natpinit

Rambutan Tree With Fruits That Never Turns Red, The Tuklapin Variety

Brother asked me where can he buy good variety rambutan seedlings. I replied, go to Cavite State University. The school was propagating rambutan seedlings, the tuklapin variety.

There are two rambutan varieties depending on how the flesh is attached to seed. The tuklapin variety – the pulp can be taken off easily from seed. The supsupin variety – the pulp is attached firmly to seeds. One should suck it hard to enjoy. If it gets too hard, then, that is not enjoyment.  The tuklapin variety is preferred by many.

Brother bought seedlings, my two uncles and mother bought too. Of course, they bought what I suggested.

After few years all the trees started bearing fruits. Mother’s tree was planted in front of her house. It also bear fruits but all of them have never turned red. The fruit was so good that a yellowish fruit was good enough for the tummy.  If someone found a yellow colored fruit, other would get it if he don’t.

I think I already told this story somewhere in this site. I just can’t remember where!

rare ripe rambutan

As of May 1, 2012.  I got a ripe rambutan from auntie’s tree. It was  supsupin. Auntie reminded me that it was really a tuklapin. She never knew why it turned out as supsupin.

Rambutan Bytes: Tuklapin, Supsupin and the Half-Half

The battle between two Rambutan varieties has long ended. Between tuklapin and supsupin. The winner was tuklapin.

several rambutan fruits

The two terms are not real variety name. They are Tagalog terms popularized by Rambutan lovers.

What is tuklapin? Rambutan is called tuklapin if the flesh is not sticking to seeds. It is more enjoyable to eat because the flesh is easier to get. Some seed testa are taken together with the flesh. The thin woody seed covering. Flat tasting and irritating in throat when swallowed. Often ruining the flavor. Pay attention to pulp instead of irritating seed coat.

What is supsupin? The Pilosopo Tasyo of defining term, it is the opposite of the above. The pulp sticks firmly on seed making it hard to remove. Anyone must suck it for a while, then discard the seeds with lots of leftover. Sucking is equivalent to Tagalog term supsupin.

The irritating part is not able to remove all the pulp from seed. Why buy supsupin if tuklapin is available? The latter should be priced relatively cheaper to attract buyers.

Lately, we were encountering rambutan fruits which are half tuklapin and half supsupin. Half of the pulp got stuck on seeds. A bit frustrating. The said fruits were coming from known tuklapin trees. Maybe those threes are half-breed, affected by cross pollination or result of other factors such as soil fertility. half tuklapin supsupin


Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Lecturer of Cocoa Foundation of the Philippines. Do coaching and consultancy services on his free time.

13 Replies to “Rambutan Seeds | Toxic when raw, edible when roasted or boiled”

  1. Hello,

    I’m currently doing research on rambutan seed.
    May I know the source of your information regarding the benefits of it?

    Thank you

  2. ey yo I better not die from this shit nigga I’m finally getting into shape and I need the toned muscle, but it’s not gonna help if I die my nigga. You know what I mean?

  3. I used to give my little dog rambutan seed, and nothing happened to him, as a matter of fact he really loved rambutan seed more than dog food.

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