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British Journal of Healthcare and Medical Research - Vol. 10, No. 6
Publication Date: December 25, 2023
DOI:10.14738/bjhmr.106.15314.
Nyam, M. A., Umaru, B. S., Wonang, D. L., Papi, D. Y., & Adolong, V. A. (2023). Comparative Studies on the Quality and Antimicrobial
Effect of the Fruit Oils of Canarium schweinfurthii Engl. (Atili), Dacryodes edulis H.J. Lam (Ube) and Persea americana Mill (Avocado).
British Journal of Healthcare and Medical Research, Vol - 10(6). 219-230.
Services for Science and Education – United Kingdom
Comparative Studies on the Quality and Antimicrobial Effect of
the Fruit Oils of Canarium schweinfurthii Engl. (Atili), Dacryodes
edulis H.J. Lam (Ube) and Persea americana Mill (Avocado)
Mary Azumi Nyam
Department of Plant Science and Biotechnology, University of Jos, Nigeria
Bethel S. Umaru
Department of Plant Science and Biotechnology, University of Jos, Nigeria
David Longwap Wonang
Department of Plant Science and Biotechnology, University of Jos, Nigeria
Danladi Yakubu Papi
Department of Plant Science and Biotechnology, University of Jos, Nigeria
Vincent Alfred Adolong
Department of Plant Science and Biotechnology, University of Jos, Nigeria
ABSTRACT
Increase in consumption of oils from plant origin has led to a wide debate regarding
their health effects. This study was undertaken to on three types of fruit oils,
Canarium schweinfuthii, Dacryodes edulis and Persea Americana to determine the
percentage yield, their phytochemical constituents, cholesterol levels and their
microbial effect on some selected fungi and bacteria species. Cold maceration
technique using n-Hexane was the extraction method used and the percentage yield
was determined. Phytochemical screening and cholesterol levels were determined
using standard methods. Antimicrobial activities were carried out on the clinical
isolates of the fungi (Aspergillus flavus, Aspergillus fumigatus and Aspergillus
terreus) and bacteria (Escherichia coli, Staphylococcus aureus and Pseudomonas
aeruginosa) using disk diffusion techniques. The results of the extraction showed
that 300g each of D. edulis had the highest percentage oil yield of 41.71%, followed
by C. schweinfuthii, 36.31% and P. Americana had the lowest amount with 18.37%.
The phytochemical screening also revealed the presence of secondary metabolites
such as steroids, anthraquinones, terpenes and cardiac glycosides, but alkaloids,
flavonoids, tannins and saponins were all absent in the oils. The cholesterol analysis
showed P. americana having the highest level of 3223.32 mg/ml (3.22%), followed
by D. edulis with 3108.69 mg/ml (3.11%) and C. schweinfurthii had the lowest,
2760.86 mg/ml (2.76%). It was observed that the oils had no antifungal activities
on the test organisms. The antibacterial activity was in a concentration-dependent
manner as S. aureus was the most susceptible to the oils with C. schweinfuthii having
the highest activities of 7.77±0.47-10.07±0.00 followed by D. edulis oil
6.67±0.35mm-9.00±0.00mm and P. americana oil which had no activity on the test
organism. D. edulis had the highest activity on E. coli 7.47±0.47-10.07±0.00 while C.
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British Journal of Healthcare and Medical Research (BJHMR) Vol 10, Issue 6, December- 2023
Services for Science and Education – United Kingdom
schweinfurthii and P. americana had no activity on the test organism. D. edulis also
had the highest activity of 6.67±0.33-10.33±0.33 which was significantly different
from C. schweinfurthii and P. americana which had no activity on the test organism,
therefore, at P<0.05, there was a significant difference in the antibacterial activities
of the oil. This implies from the study that the secondary metabolites found in the
oils possess healthy properties. The cholesterol levels of the oil samples showed
that the oils contain an acceptable amount of cholesterol and the antibacterial
activities of these oils showed that they have significant effects on the bacteria used
in the study; hence, the results of these findings support the use of these oils as
therapeutic agents.
Keywords: Fruit oils, cholesterol level, antifungal and antibacterial activities
INTRODUCTION
Vegetable oils are a group of fats that are derived from seeds, nuts, cereal grains, and fruits. It
is important to understand that not all of these vegetable oils are liquid oils at ambient
temperatures. In addition, not all of the vegetable oils produced in commercial quantities are
considered to be edible in the sense of being typical dietary components (Hammond, 2003).
Edible vegetable oils are mainly used in cooking, as salad dressings, in manufacture for
margarines, spreads, and bakery.
Olive oil is the oldest known edible oil used in humans’ diet. It is a main constituent of the
traditional Mediterranean diet, which has a protective role against a number of diseases
including cardiovascular disease and cancer (Savva et al., 2016). An important characteristic of
these sources of oil from plants is the high degree of unsaturation in their constituent fatty acids
which directly relates to their higher susceptibility to oxidative deterioration (Roxana and
Ovidiu, 2016). Vegetable oils and fats are principally used for human consumption but are also
used in animal feed, for medical purposes, and for certain technical applications. Oils are also
gotten from; soybean, rape, sunflower, peanut, cotton, corn, grape, fiberflax, safflower, rice,
perilla, oil palm, olive, walnut, hazelnut, pine, cocoa.
Edible vegetable oils form a vital part of the human diet and can provide the energy and fatty
acids needed by the body and promote the digestion and absorption of fat-soluble vitamins (Ma
et al., 2014). The content and proportion of oil intake are closely related to human health.
Consuming an appropriate amount of oil is conducive to the normal metabolism of fat, while
excessive ingestion leads to the deposition of fat in the body, resulting in hypertension,
hyperlipidemia and other diseases (Meng et al., 2009). Edible vegetable oils also contain certain
amounts of vitamin E and phytochemicals, such as phytosterols and sqaulene (Wu et al., 2019).
Furthermore, edible vegetable oils are rich in phytosterols, providing an excellent way for
humans to ingest these compounds (Gao et al., 2015).
There are issues of high cholesterol content in some fruit oils that are consumed by humans,
thus, posing a great challenge to the quality nature of such oils and also different health
challenges; furthermore, microorganisms are known to cause infections in humans and some
strains are resistant to the existing synthetic drugs, thereby posing great concern to health and
other commercial products. Hence, the need to find other sources of oils with low cholesterol
content which can inhibit the metabolic activities of certain microorganisms, especially
pathogenic microorganisms.
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Nyam, M. A., Umaru, B. S., Wonang, D. L., Papi, D. Y., & Adolong, V. A. (2023). Comparative Studies on the Quality and Antimicrobial Effect of the
Fruit Oils of Canarium schweinfurthii Engl. (Atili), Dacryodes edulis H.J. Lam (Ube) and Persea americana Mill (Avocado). British Journal of Healthcare
and Medical Research, Vol - 10(6). 219-230.
URL: http://dx.doi.org/10.14738/bjhmr.106.15314.
MATERIALS AND METHODS
Plant Materials
Fresh and ripened fruits of Canarium schweinfurthii, Dacryodes edulis and Persea americana
were collected from local marketers in Chobe and Farin gada markets of Jos north LGA, Plateau
state, in June 2021. The fruits collected were taken to the herbarium of the Department of Plant
Science and Biotechnology, University of Jos, Plateau State, for identification. The fruits were
sorted properly to remove any dirt or foreign materials and then they were weighed using a
weighing balance and 300g was gotten for each specimen. The fruits were then washed in cold
tap water to remove any dirt adhering to the surface of the fruits. A sterilized laboratory knife
was then used to separate the pulp from the seeds of the fruits of C. schweinfurthii, D. edulis and
P. americana.
The pulp was then cut into smaller pieces and oven dried at 600C for 24 hours to remove the
moisture content and get the dry matter of the fruits. After the fruits pulp were properly oven
dried, it was now pulverized using a laboratory mortar and pestle in order to get the granulated
form of the fruits pulp. Using a weighing balance, the granulated form of Canarium
schweinfurthii, Dacryodes edulis and Persea americana were weighed and recorded. The
powdered pulp of Canarium schweinfurthii, Dacryodes edulis and Persea americana were now
appropriately stored in sterile air-tight bottles and were properly labeled until when needed.
Extraction By Cold Maceration
The extraction method used in this study was maceration method as described by Abdulkadir
et al. (2015). The powdered plant samples (108.92g, 125.13g, and 55.11g) each of Canarium
schweinfurthii, Dacryodes edulis and Persea americana were soaked in 500ml of n- Hexane
solvent in separate 1 liter capacity conical flasks stopped and kept for 48 hours. The cold
extracts thus obtained were kept in a water bath for 1 hour at 69oC. After cooling, the extracts
were filtered successively through ordinary chesses cloth and Whatmann filter paper. The n- Hexane extracts of Canarium schweinfurthii, Dacryodes edulis and Persea americana were
evaporated in order to get the pure samples of the oil. The oils gotten were now stored in sterile
bottles, labeled appropriately and kept at 370C (room temperature) until needed.
Determination of the Percentage Yield of the Extract
This was done using the formula described by Falana and Nurudeen (2020). The yield of extract
(extractable components) expresses on dry weight basis of pulp was calculated from the
following equation: Yield (g/100g) = (W1x 100)/W2 where W1 is the weight of the extract
residue obtained after solvent removal and W2 is the weight of peel or pulp taken.
Phytochemical Analysis
Phytochemical analysis for qualitative detection of alkaloids, flavonoids, tannins, saponins,
terpenes, steroids, carbohydrates, cardiac glycosides and anthraquinones were carried out on
the extracts as described by Sofowora (2008).
Test for Alkaloids:
About 2ml of each plant extract was stirred with 3ml of 1% aqueous hydrochloric acid on
steams bath and filtered. 1ml of the filtrate was treated with a few drops of Mayer’s reagent and
a second 1ml portion was treated similarly with Dragedorffs reagent. Precipitation with either
of those reagents was taken as evidence for the presence of all alkaloids (Sofowora, 2008).
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Test for Saponins:
About 2ml of each plant extracts were added to 4.0ml of distilled water in a test tube and the
test tube was stopped and shaken vigorously for about 30 seconds. The test tube was allowed
to stand for half an hour. Frothing which persist on warming was taken as preliminary evidence
for the presence of Saponins (Sofowora, 2008).
Test for Flavonoids:
Lead sub-acetate test 2ml of each plant extract was dissolved in 5ml of distilled water, heated
for 5 minutes and filtered. The filtrate was allowed to stand for 5 minutes to cool and about 2-
3 drops of lead acetate solution was added to the filtrate. A yellow-colored precipitate indicated
the presence of flavonoids (Sofowora, 2008).
Test for Tannins:
About 2ml of each plant extract was stirred with 1ml of distilled water, filtered and few drop of
ferric chloride were added to the filtrate. A blue-black, green precipitate was taken as evidence
for the presence of tannins (Sofowora, 2008).
Tests for Anthraquinones:
About 2ml of each plant extract was taking into a test tube and 5ml of chloroform was added
and shaken for 5 minutes. The extract was filtered and the filtrate shaken with an equal volume
of 100% NH3 solution. A pink –violet color in the ammonical layer indicate the presence of free
anthraquinones (Sofowora, 2008).
Test for Cardiac Glycosides:
About 3ml of each plant extract was dissolved in 1 ml of glacial acetic acid containing one drop
of FeCl2(Ferric chloride) solution. It was then under-layered with 1 ml of concentrated H2SO4.
A brown ring was observed at the interphase, which is a positive reaction for the presence of a
deoxy-sugar characteristic of cardiac glycosides (Sofowora, 2008).
Test for Carbohydrates:
About 1ml of each plant extract was dissolved in 3ml of distilled water and mixed with a few
drops of Molisch reagent (10% solution of α- naphthol in alcohol). Then 1ml of concentrated
sulphuric acid was carefully added down the side of the inclined tube so that the acid forms a
layer beneath the aqueous solution without mixing it. A reddish or violet ring at the junction of
the liquids was observed indicating the presence of carbohydrate (Sofowora, 2008).
Cholesterol Screening
The cholesterol content test was carried out as described by Ojiako and Akubugwo (1997).
About 0.1ml of the sample oil extracts each and standard cholesterol dissolved in chloroform
in ratio 1:10 was evaporated to dryness in water bath at 500C. Glacial acetic acid (3.0mL) and
3.0mL of color reagent (a solution of ferric chloride/glacial acetic acid/sulphuric acid), was
added to each sample and the standard, then shaken vigorously to dissolve the oil. Blank
contained 2.0mL of chloroform, 3.0mL glacial acetic acid and 3.0mL of color reagent. After
cooling for 30mins at room temperature, absorbance of standard and samples were read at
560nm using JENWAY 6310 spectrophotometer.