EXTRACTION, CHARACTERIZATION AND ANTIMICROBIAL SCREENING OF WHITE STAR APPLE (Crysophyllum Albidum) SEED OIL
Crysophylum albidum oil was extracted from its seed. The percentage yield was 2.56%. The characterization of the oil showed showed that the refractive index is 1.487, peroxide value is 45.4mg/kg, iodine value is 50.76g, saponification value is 105.188, free fatty acids 47.46 and acid value is 94.92. The Punched Ager Diffusion Method was used to assay for the antimicrobial and anti fungal properties of the oil in the test isolate. The antimicrobial and anti fungal activity showed some inhibitory effects against test organisms; Staphylococcus aureus, E. coli, B. subfilis, C. albican and A. flavons, but non for S. pyogens. The minimum inhibitory concentration of these test organisms are as follows; Staphylococcus aureus0.16, E. coli 0.06, B. subfilis 0.14, C. albican 2.50and A. flavons 0.40.
The pharmacological screening confirmed the medical value of this plant oil and it established a good support for the sample in herbal medicine and as a base for the development of new drugs and phytomedicine.
TABLE OF CONTENT
Table of content
1.2 TYPES OF OIL
1.2.1 Drying oil
1.2.2 Semi-Drying Oil
NON- DRYING OIL
1.3 COMPOSITION OF OIL
1.7 BOTANIC DESCRIPTION
1.8 FUNCTIONAL USES
MATERIALS AND METHODS
2.0 SAMPLE COLLECTION
2.1 OIL EXTRACTION
2.2 DETERMINATION OF SPECIFIC GRAVITY
2.3 DETERMINATION OF DENSITY
2.4 DETERMINATION OF FREE FATTY ACID
1. DETERMINATION OF SAPONIFICATION VALUE
2. DETERMINATION OF IODINE VALUE
3. DETERMINATION OF PEROXIDE VALUE
4. ANTI-MICROBIAL ACTIVITY SCREENING
1. REAGENTS AND MEDIA
2. PREPARATION OF FUNGAL TEST ORGANISM
3. PREPARATION OF THE SENSITIVE TEST AGAR
4. PREPARATION OF THE NUTRIENT DEXTROSE
2.8.5 THE PUNCHED AGAR DIFFUSION METHOD AS
RECOMMENDED BY BRYANT (1972)
2.7.6 BACTERIAL INOCULATION AND INCUBATION
2.8.7 FUNGAL INOCULATION AND INCUBATION
READING INHIBITION ZONES OF THE OIL
TABLE 3.1 ORGANOLEPTIC CHARACTERISTICS OF
Crysophylum albidum SEED OIL
3.2 CHARACTERIZATION OF THE SAMPLE
TABLE 3.3 RESULT OF ANTI-BACTERIAL ACTIVITY OF C.
albidum OIL ON TWO GRAM POSITIVE BACTERIA
TABLE 3.4 RESULT OF ANTI-BACTERIAL ACTIVITY OF C.
albidum OIL ON TWO GRAM NEGATIVE BACTERIA
TABLE 3.5 RESULT OF ANTI-FUNGAL ACTIVITY OF C. albidum
OIL ON TWO TEST FUNGI
3.6 RESULT OF MINIMUM INHIBITORY CONCENTRATION
(MIC) OF C. albidum OIL ON SIX TEST ORGANISM
Oil belongs to the body of lipids which is a broad group of naturally occurring hydrophobic molecules that contain carbon. They include fats, waxes, sterols, fats-soluble vitamins, etc. This is divided into saturated and unsaturated fatty acid. Saturated fatty acids are known as fats usually obtained from animals while oil belonging to the unsaturated group is usually gotten from plants.
Crysophyllum albidum (White Star Apple) is a plant grown in the mid-Africa particularly in Nigeria, Cameroon, etc. Crysophyllum albidum (G. Don) is a tropical edible fruit tree. It belongs to the family sapotaceae which has up to 800 species and make up almost half the order Ebernales. Okigbo and Okafor reported that a few species of Crysophyllum grow in the boarder regions between the forest and Savanna in Nigeria. The plants as reported by Bada, can be found in Nigeria, Cameroon, Cote d’ Ivoire, Uganda and Niger republic. The species is called different names depending on the locality. The table below shows some locality and names of the species.
SOME LOCALITIES AND THE SPECIE’S NAMES.
Chrysophyllum albidum (G.Don)
Flowering is usually from April to June. The flowers are sessile and occur in clusters in the leaf axils of the fruiting branch. The fruits are normally January to March but the fruit have been seen recently in November.
Fruiting branch of C. albidum
When ripe, the fruits are pale orange, edible, ovoid in shape and pointed at the apex. It is a berry with crescent shaped seeds. See the diagram below.
C. albidum Fruits with revealed seeds.
C. albidum fruit contains 8.8% protein, 17.1% oil, 21% sugar 11% starch . The fruits are generally eaten by both old and young people. C. albidum fruits have been reported to be the highest source of ascorbic acid, excellent source of vitamins, irons, flavour to diets and raw material to some manufacturing industries . C. albidum has been classified by Okafor  and Okigbo  as a wild uncultivated fruit tree which occurs naturally in the high forests or bushes and seldom planted as a fruit tree. Boys, girls and women generally pick C. albidum fruits from the wild forest for their consumption and sales. C. albidum fruit is a great source of economic empowerment to rural dwellers. This is because a fruit is sold at N5 (Five naira), N10 (Ten naira) depending on the size of the fruit. The anti-microbial effect of African star apple (C. albidum) belonging to the family sapotaceae is that the roots and leaves are used for medicinal purposes. The seeds are used for local games or discarded. The seeds of C. albidum are usually thrown away and no report has existed on the use of oils from non-utilized oil seeds for the treatment of wounds or as skin ointments.
OBJECTIVES OF THE RESEARCH
The objectives of this research work are;
1. To extract and characterize the oil obtained from C. albidum seed.
2. To determine the antifungal/antibacterial activity of C. albidum seed oil.
1.2 TYPES OF OIL
As a result of saturation and unsaturation of oil, they are able to be classified into drying, non-drying and semi-drying based on the degree of double bond.
1.2.1 Drying oil
They are those that absorb oxygen rapidly on exposure to air and form thin elastic film. They act in this way because they contain a large proportion of unsaturated fatty acids, as linolenic acid (C18H30O2) with three double bonds in its molecules. The rapid rate at which the oil dries in air depends on its ability to absorb iodide. Their iodine numbers varies usually above 135. this shows high level of unsaturation.
1.2.2 Semi-Drying Oil
This form a soft surface film after long exposure to air. They contain a large portion of linoleic acid (C18H32O2) and oleic acids (C18H34O2) with little linolenic acid (C18H28O2). The most important oil in this class is from seeds of plants. Iodine value ranges from 110 – 135.
1.2.3 NON- DRYING OIL
These are class of acids that remain as liquid and does not form film on exposure to air. This implies that it reacts slowly or not at all with oxygen and so has low iodine value less than 90. The saturated oils are cashew nut oil, ground nut oil and olive oil are examples. Iodine number is 110 and below.
1.3 COMPOSITION OF OIL
According to Pine, the fatty acid of the triglyceride structure represent over 92% of the total weight. The balance consisting of the glyceride radical and minor percentage of the non-glyceride constituents such as cholesterol, phytosterols, phosphatide, vitamins and moisture. The total amount of non-glyceride components are usually not over 3% of the total oil base products.
Only a few of the glycerides occurring in nature are of the simple type, most are mixed triglycerides, that is, one molecule of glycerol combines with two or three different fatty acids. 
According to Kirk-Othmer the characteristic brownish-red colour of most oils and some of animal fats is derived from carotinoid pigments. White Star Apple seed oil which is usually light in colour contain about 0.2% beta carotene. Other purer seed oil like soybean may contain sufficient chlorophyll related compounds. C. albidum seed oil is strongly coloured by pigment of the gossypol type. All of these pigments are readily reduced to low level of alkali refining of the oil absorbed bleaching. However, brownish or reddish pigment found in carbohydrate decomposition product is relatively resistant to refining treatment.
According to Kirk-Othmer, the common vegetable oil, as a source of vitamins are only important with respect to view content of tocophenols which posseses vitamin E activity.
Most vegetable oils or fats contain mineral proportions (0.5 – 0.20) of the antioxidants, which serve to inhibit atmospheric oxidation, the course of rancidity. The common antioxidant of vegetable oil or fat are tocophenol in a few cases, antioxidants peculiar to specific oil or fat are known. Antioxidants are not removed to any large extent by refining to other common edible oil processing treatment.
The testaless seeds of Chrysophyllum albidum G Don from Nigeria were analysed and found to contain saponins with a foaming index < 100, 71 g kg-1 crude fibre, 109 g kg-1 total ash, 316 g kg-1 carbohydrates, 364 g kg-1 proteins and 52 g kg-1 fixed oil on dry weight basis. They were also found to have appreciable amounts of K, Ca, P and Mg. Further analysis of the carbohydrates showed the presence of starch and the reducing sugars arabinose, galactose, glucose and mannose. The profile of amino acids showed the seeds to be rich in the essential amino acids lysine, threonine, leucine, isoleucine and phenylalanine. The fatty acids of fixed oil include 16-3% palmitic acid, 5-9% stearic acid, 41-3% oleic acid, 30-9% linoleic acid and 1-6% arachidic acid.
It was reported in 1983 that fruit pulp contains 21.8mg/100g ascorbic acid, while the skin contains 75mg/100g, while Edemet. al.,  reports 446.1 and 239.1mg/100g for pulp and skin respectively. The latter authors also indicate that proximate analysis of fruit pulp was protein (8.8%), lipid (15.1%), ash (3.4%), carbohydrate (68.7%) and crude fibre (4.0%), with only minor differences between pulp and skin. With the exception of calcium (100 v 250 mg/100g) and iron (10 v 200 mg/100g) in pulp and skin respectively, the mineral content of these components of the fruit were also very similar. According to Achinewu, the levels of toxic substances in both the mesocarp and the pericarp were low, although the juice was highly acidic. Edem et. al.,  on the other hand, identified high levels of tannins in pulp (627 mg/100g) and lower levels in peel (264 mg/100g). Fruit storage was best at 10oC, while for the kernel the traditional method of storing in layers of red clay was best. The juice of fruits has potential as an ingredient of soft drinks and can be fermented for wine or other alcohol production. The seeds of this species are not particuarly rich in lipids (3.2%), but linoleic (38.4%) and oleic (29.6%) acids are the main fatty acids present. Ajewole & Adeyeye have, however, reported higher lipid content (16.6%) and confirmed that unsaturated fatty acids are the main component of the oil (74%) and hence desirable in the context of heart disease risk reduction. The residual cake also has potential for animal feed.
1.7 BOTANIC DESCRIPTION
Crysophyllum albidum is a small to medium buttressed tree species, up to 25-37 m in height with a mature girth varying from 1.5 to 2 m. Bole is usually fluted, frequently free of branches for 21 m. Bark thin, pale brownish-green, slash exuding white, gummy latex. Leaves are simple, dark green above, pale tawny below when young and silver-white below when mature, oblong-elliptic to elongate obovate elliptic, 12-30 cm long, 3.8-10 cm broad; apex shortly acuminate, base cuneate; primary lateral nerves widely spaced, 9-14 on each side of the midrib; secondary lateral nerves indistinct or invisible; petiole 1.7-4.2 cm long. Flowers shortly pedicellate, in dense clusters in the leaf axils or from above the scars of fallen leaves; calyx 5-lobed, 3 mm long, rusty pubescent outside, creamy white, the lobes equaling the tube in length. Fruits almost spherical, slightly pointed at the tip, about 3.2 cm in diameter, greenish-grey when immature, turning orange-red, yellow-brown or yellow, sometimes with speckles, 5 celled, with 5 brown seeds in yellowish, pleasantly acid pulp. Seeds 1-1.5 x 2 cm, beanlike, shiny when ripe, compressed, with one sharp edge and a star-shaped arrangement in the fruit. The generic name is based on Greek words for ‘gold’ and ‘leaf’ and refers to the leaves of some species that are often covered with golden hairs underneath.
1.8 FUNCTIONAL USES PRODUCTS
Food: The fleshy and juicy fruits, which are popularly eaten, are the potential source of a soft drink. Timber: Wood brownish-white, soft, coarse and open in grain; very perishable in contact with the ground. Easy to saw and plane, nails well, takes a fine polish, and therefore is suitable for construction work, tool handles and similar purposes. Alcohol: The fruits can be fermented and distilled for the production of wine and spirits..