Collection and Identification of Plant materials:
Ripe and fresh Chrysophyllum albidum fruits used for this study were purchased from Utako Market, in Abuja, Nigeria. The fruit were identified and authenticated at the Herbarium of the Department of Biological Sciences, University of Abuja, Nigeria.
Chemicals and Reagents:
The chemical and reagents used were all from Sigma Aldrich.Media used were from hi-media laboratories limited, India. Clinical test isolates used were collected from National Institute for Pharmaceutical Research and Development (NIPRD).
Preparation of Plant Materials:
The sample was prepared according to the methods described by Anibijuwon and Udeze [Anibijuwon and Udeze 2009]. The fruit samples were washed and the seeds removed from the fruits and air dried to constant weight. The dried seeds were deshelled and the cotyledon pounded into smaller granules using laboratory Mortar and pestle. The blender was used to pulverize the pounded cotyledon. The pulverized cotyledon sample was kept in an air tight container.
Proximate Composition Analysis:
The proximate analysis was carried out in the Department of chemistry SHEDA Science and Technology Complex Gwagwalada Abuja. Each sample (pulverized seed cotyledon of C. albidum fruits) was analysed in triplicate. This was carried out according to the method of AOAC [1990]
Moisture Content Determination:
Two grams of each of the cotyledon sample was weighed into dried weighed crucible. The samples was put into a moisture extraction oven at 105 0C and heated for 3 hours. The dried samples was put into desiccators, allowed to cool and reweighed. The process was reported until constant weight was obtained the difference in weight was calculated as a percentage of the original sample
Percentage moisture =
Where;
W1 = Initial weight of empty dish
W2 = Weight of dish + Un-dried sample
W3 = Weight of dish + dried sample
Ash Content Determination:
Two grams of each of the cotyledon samples was weighed into crucible, heated in a moisture extraction oven for 3hour at 100 0C before being transferred into a muffle furnace at 550 0C until it turned white and free of carbon. The sample was then removed from the furnace, cooled in a desiccator to a room temperature and reweighed immediately. The weight of the residual ash was then calculated as ash content
Crude Protein Determination:
The micro kjeldahl method described by [105] was used. Two grams of each of the sample was mixed with 10ml of concentrated H2SO4 in a heating tube. One table of selenium catalysts was added to the tube and mixture heated inside a fume cupboard. The digest was transferred into distilled water. Ten millimeter portion of the digest mixed with equal volume of 45% NaOH. Solution and poured into a kjeldahl distillation apparatus. The mixture was distilled and the distilled collected into 4% boric acid solution containing 3 drops of methyl red indicator. A total of 50ml distillate was collected and titrated as well. The sample was duplicated and the average value taken The nitrogen content was calculated and multiplied with 6.25 to obtain the crude protein content. This is given as
Percentage Nitrogen =
Where;
N = Normality of the titrate (0.1N)
VF = Total volume of the digest = 100ml
T = Titre value
Va = Aliquot volume distilled
Crude Fiber Determination:
Two grams (2g) sample and 1g asbestos were put into 200ml of 1.25% of H2SO4 and boiled for 30 minutes. The solution and content then poured into Buchner funnel equipped with muslin cloth and secured with elastic band. This was allowed to filter and residue was then put into 200ml boiled NaOH and boiling continued for 30 minutes, then transferred to the Buchner funnel and filtered. It was then washed twice with alcohol. The material obtained washed thrice with petroleum ether. The residue obtained was put in a clean dry crucible and dried in the moisture extraction oven to a constant weight. The dried crucible was removed, cooled and weighed. Then, difference of weight (i.e. loss in ignition) is recorded as crucible fiber and expressed in percentage crude fiber,
Percentage crude fibre = x
Where;
W1 = Weight of sample before incineration
W2 = Weight of sample after incineration
W3 = Weight of original sample
Fat Content Determination:
Two grams of the cotyledon sample was loosely wrapped with a filter paper and put into the thimble which was filled to a clean round bottom flask, which has been cleaned, dried and weighed. The flask contained 120ml of petroleum ether. The sample was heated with a heating mantle and allowed to reflux for 5hours. The heating was then stopped and the thimbles with the spent samples kept and later weighed. The difference in weight was received as mass of fat and is expressed in percentage of the sample. The percentage oil content is percentage fat
Percentage fat = x
Where;
W1 = Weight of the empty extraction flask
W2 = Weight of the flask and oil extracted
W3 = Weight of the sample
Carbohydrate Content Determination:
The nitrogen free method described by [105] was used. The carbohydrate is calculated as weight by difference between 100 and the summation of other proximate parameters as Nitrogen Free Extract (NFE) percentage carbohydrate
(NFE) = 100 – (M + P + F1 + A + F2)
Where;
M = Moisture
P = Protein
F1 = Fat
A = Ash
F2 = Crude Fibre
Energy Content Determination:
Gross energy was calculated based on the formula used by Ekanayake et al., [1990]: Gross energy (kJ per 100 g dry matter) = (crude protein × 16.7) + (crude lipid × 37.7) + (carbohydrate × 16.7).
Mineral Analysis:
In the mineral analysis, the samples were ashed at 550OC and the obtained ash was boiled with 10 ml of 20% hydrochloric acid in a beaker and then filtered into a 100 ml volumetric flask. The filtrate was made up to the mark with deionized water. The minerals were determined from the resulting solution. Flame emission photometer was used for sodium (Na) and potassium determination (AOAC, [2000] while Atomic Absorption Spectrophotometer (AAS) (PerkinElmer, Analysist A700) was used for calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), chromium (Cr) and copper (Cu) at SHEDA Science and Technology Complex Gwagwalada Abuja. All values were expressed in mg/100g.