Establish the potential usefulness of the ackee seed

ACKEE IS the national fruit of Jamaica and is a major source of food. In other regions, components of the plant have traditionally been used for a variety of conditions. It is widely found throughout the West Indies and has been naturalised to parts of Central America, Florida, and Hawaii.

The tall, leafy tree grows to approximately 12 metres and produces fruit two times a year, between January and March and then between June and August. Its oval, compound leaves have five pairs of leaflets, the longest of which is approximately 15 centimetres at the tip. The plant produces small, greenish-white flowers, while the red fruit pods split open at maturity, exposing three shiny, black seeds embedded in a white, waxy aril.

Unripe ackee fruit is toxic, causing severe hypoglycemia, often accompanied by convulsions and death

In a recently published paper, researchers from the Department of Chemistry, Faculty of Science and Technology, The University of the West Indies, Mona explored the potential usefulness of the ackee seed by the characterisation of its extracts.

Ackee is a significant foreign exchange earner for Jamaica, of which the arilli of the fruit are processed to make canned ackee in brine, whereas the seeds, raphe and pods are discarded.

The findings suggest that ackee seeds are a rich source of bioactive components. Through gas chromatography mass spectrometry, the researchers were able to identify several analytes.

Ackee seed oil is rich in gondoic acid, which has anti-inflammatory properties. Fourier Transform Infrared Spectroscopy (FTIR) was utilised to detect several bands that are characteristic of the methylencyclopropane moiety present in hypoglycin B, a toxin present in ackee seeds. FTIR could potentially be utilised as a facile method of detecting hypoglycin.

According to Dr Andrea Goldson-Barnaby, senior lecturer in the Department of Chemistry, Faculty of Science and Technology, during the processing of canned ackee in brine, the seed, raphe and pods are discarded.

“As we move towards more sustainable agricultural practices, our group wanted to investigate the potential applications of the ackee seed by characterising its chemical composition. Our main objective was to identify the chemical components within the ackee seed, which will guide further commercial applicability. We also wanted to further characterise the toxins present within the ackee seed,” Dr Goldson-Barnaby said.

Major findings of the research, she said, include further characterisation of the cyclopropyl moiety within the toxic component hypoglycin B utilising Fourier Transform Infrared Spectroscopy, profiling of the aqueous and non-aqueous extracts of the ackee seed, which led to the identification of several metabolites with free radical scavenging activity.

“This type of research is important as it provides the basis for commercial applications. The oil and starch content of the ackee seed can be further exploited and utilised in the production of value-added products such as cosmetics and spray starch,” Dr Goldson-Barnaby said.

This Jamaican fruit has been sought for many folk-medicinal benefits. Repeated doses of aqueous seed extract have been used to eliminate parasites. Also, ackee pod poultice has been used to treat skin infections, ringworm and liver spots. The ripe arils of ackee along with sugar and cinnamon have been used to treat fever and dysentery.

The ackee tree bark mixed with certain spices can relieve pain. The new leaves are crushed and applied to the forehead to ease a severe headache; when mixed with salt, it is applied on ulcers. Ackee leaf tea can also be used to alleviate cold.

Ackee arilli and seed oil extracts are currently not utilised commercially. They, however, show promising characteristic properties for utilisation as an edible oil or in the cosmetic industry. The oils had similar characteristics to that of other commercially available oils.

“Ackee arilli oil is expected to be stable to oxidation due to its low levels of unsaturation, which was confirmed from its iodine value. Its saponification value illustrates its potential application in the surfactant industry. The antioxidant properties of the oils are shown from their free radical scavenging activity and phenolic content. The peroxide value revealed that ackee seed oil was more oxidised than arilli oil,” Dr Goldson-Barnaby said.

Ackee lipid extracts may be utilised in the production of value-added food commodities, as well as in the cosmetics industry. The saponification value, iodine value, and fatty acid composition of ackee oil exhibit similarity to that of other oils which are utilised commercially.

keisha.hill@gleanerjm.comSource: Department of Chemistry, Faculty of Science and Technology, University of the West Indies, Mona.