(By Temitope Obayendo)
At a glance, the African cherry appears rather small and insignificant in comparison with many other fruits. Yet experts on nutrition have repeatedly affirmed its uncommon nutritional benefits, as well as its efficacy in the prevention and management of diabetes and heart diseases.
Botanically called Chrysophyllum albidum, the African cherry (also known as African star apple) belongs to the Sapotaceae family. It is popularly called agbalumo among the Yourbas, while the Igbos called it udara.
C. Albidum is sub-spherical in shape, about 3cm in diameter, usually 5-celled and contains an edible, sweet fruit-pulp. The skin or peel is orange to golden yellow when ripe and the pulp within the peel may be orange, pinkish, or light yellow. Within the pulp are at least five seeds, which are not usually eaten.
The fleshy pulp is usually eaten as snack and it has been found to have high contents of ascorbic acid. It is also acclaimed to be an excellent source of vitamins, irons and flavours to diets.
In Benin, where researchers recently focused on the used pattern of the fruit, the African cherry occurs on ferallitic soils. It is a lowland rain forest tree species, which can reach 25 to 37m in height at maturity with a girth varying from 1.5 to 2m. Its nature occurrence has been reported in diverse ecozones in Nigeria, Uganda, Niger Republic, Cameroon and Cote d’ Ivorie.
In a chat with Professor Ignatius A. Onimawo of the Department of Biochemistry, Ambrose Alli University, Ekpoma, Edo State, on the nutritional contents of C. Albidum for human consumption, he said the fruit serves as a good source of calcium, with each serving providing an individual with 10 per cent of the daily requirement.
Onimawo, who is professor of nutritional biochemistry, asserted that the calcium lends strength to human’s bones and teeth, and may also lessen symptoms of premenstrual syndrome, such as cramping and abdominal bloating.
“This fruit also contains 5 per cent of the daily recommended value per serving of vitamin C and vitamin A. Additionally, one serving of cherry serves up to 2 per cent of iron, a mineral vital for oxygenating your body, that you need every day”, he explained.
Speaking on other health benefits of the African cherry, the expert noted that cherries may have particular benefits for diabetics. Citing a research published in the September 2009 edition of the African Journal of Pharmacy and Pharmacology, he said the result indicated that the leaves of the fruit reduced glucose levels in diabetic rabbits, the same function that insulin in the human body performs.
However, he said more research is needed to determine the effectiveness of cherry leaves to control diabetes in humans.
Onimawo further referred to a study by researchers at the Department of Biological Sciences, College of Science and Technology, Covenant University, Ogun State, Nigeria. The study showed that the local cherry fruit lowered blood sugar and cholesterol, and could be useful in preventing and treating heart diseases.
“Methanolic extracts of the cotyledons from the seeds of chrysophyllum albidum led to the isolation of eleagnine, tetrahydro-2-methylharman and skatole,” he said. “Eleagnine was found to be the main compound responsible for its antimicrobial activity. Eleagnine was further shown to exhibit anti-nociceptive, anti-inflammatory and antioxidant activities. The seed cotyledon has been reported to possess anti-hyperglycemic (lowers high blood sugar) and hypolipidemic (lower blood cholesterol) effects.”
The researchers, who investigated the effects of oral administration of the leaf extract of the African cherry on biochemical and haematological parameters in albino rats for 16 days, wrote: “In conclusion, the study has demonstrated that the leaf extract of Chrysophyllum albidum may not cause any adverse effect on the biochemical and haematological indices of toxicity. Moreover, the extract was found to possess anti-platelet and hypoglycemic (lowers blood sugar) properties and might be employed in the management of myocardial infarction (heart attack) and diabetes mellitus, respectively. Further investigation is needed to establish the anti-platelet property of the extract.”
Onimawo, a public health nutritionist, also quoted from another study conducted by researchers at the Forest Research Institute, Ibadan, Oyo State, which showed that the African cherry leaves exhibited strong antibacterial activity against common bacteria isolates.
Titled, “Antibacterial Activity and Phytochemical Screening of Chrysophyllum Albidum Leaves”, the study was published in the Asian Journal of Food and Agro-Industry.
Since the fruit is seasonal, and always available in the summer, Onimawo advised that the fruit pulp could be extracted and packaged in bottles and stored in refrigerator for proper preservation. And now that fruit is in abundance, he urged people to consume it liberally as a great source of phytochemical.
According to Onimawo, the proximate composition analysis of C. Albidum is as follows:
Moisture 66.67 per cent; carbohydrate 78.34 per cent; protein 5.66 per cent; fibre 4.50 per cent; fat 9.83 per cent; ash 2.12 per cent and total energy value 420.42 kcal. The ascorbic acid content is 19.68 per cemt.
The anti-nutrients composition are: oxalate 4.95mg, saponins 3.66 per cent, cyanogenic glycoside 0.17 per cent, phytate 0.02 per cent and tannins 0.03 per cent.
Additionally, a research on “Evaluation of proximate compositions and mineral elements in the star apple peel, pulp and seed” by Ukana D. Akpabio, Aniekan E. Akpakpan, and Godwin N. Enin of the Department of Chemistry, University of Uyo, Akwa Ibom State, suggests that the African star apple fruit is an edible fruit of uncommon nutritional benefit.
In the study, recently published in the Journal of Basic and Applied Scientific Research, the peel, pulp and seed were analysed to determine the proximate composition and mineral elements. The findings showed that the pulp contains greater amounts of crude fibre, fat, ash and caloric value, while greater amount of moisture was found in the peels.
Carbohydrate content and crude protein was higher in the seed. Mineral elements composition revealed that the pulp has greater amounts of sodium and iron, while the peel contains greater amounts of potassium and zinc. Calcium and magnesium were higher in the seed.
Moisture contents of the star apple peel, pulp and seed were 47.95 per cent, 32.65 per cent and 26.55 per cent respectively with an average of 35.76 per cent. This clearly shows that the peel contains much moisture.
Moisture content is one of the most important and most widely used parameter in food processing; hence, the star apple’s seed can easily be processed and preserved, since it contains less moisture.
Crude protein contents of the star apple peel, pulp and seed were 6.68 per cent, 4.73 per cent and 8.75 per cent respectively with an average of 6.73 per cent. The Food and Nutrition Board of Nigeria (1972) recommends 56kg of protein per day in the diet of adult men weighing 70kg and 40kg for women weighing 56kg of body weight.
The Fat contents of the star apple peel, pulp and seed were 8.94 per cent, 10.00 per cent and 3.45 per cent respectively with an average of 7.46 per cent. Fat is an excellent source of energy, enhances transport of fat soluble vitamins, insulates and protects internal tissues and contributes to vital cell processes.
The star apple is a folk remedy in several countries, although no research exists to confirm this. The seeds of the fruit may be useful in reducing fevers and treating diarrhoea. Some people also eat the fruit to reduce the inflammation associated with laryngitis and pneumonia. Other uses, including treatment for hypertension, tooth abscesses, heart problems, intestinal issues and cancer exist; but it is strongly advised not to eat star apple for any medical condition without first consulting a qualified physician.
Eating a serving of star apple contributes 3g of fibre to the recommended daily intake of 25 to 38g. Fibre provides bulk to your diet, a factor that can make your stomach feel fuller for longer. This can keep you from eating too much, and it may help you lose weight. This nutrient can also help protect you from diabetes and some forms of cancer.
1-cup serving of fresh star apple contains 67 calories. Eating star apple as a snack is a good choice as it provides no fat and the calories are low; however, these may not be enough calories to ease hunger pains or boost energy levels, as between-meal snacks are meant to do. The Diet Channel notes that 100 to 200 calories per snack is best. Consider eating an oz. of cheese or a tsp. of peanut butter to boost the number of calories into this range.
One serving of star apple also has 15g of carbohydrates, or 11.5 per cent of the 130g suggested for daily consumption by the Institute of Medicine.
Journal of Basic and Applied Scientific Research, 2012
Journal of Ethnobiol Ethnomed. Oct. 2012