Chemistry-Scholarly Publications

Permanent URI for this collection

https://ir.unilag.edu.ng/handle/123456789/3380

Browse

Recent Submissions

Now showing 1 - 5 of 432
  • Item
    Open Access
    SUPERIORITY OF GERMINATED OVER RAW SAMPLE IN PROXIMATE COMPOSITION AND OVER BOTH RAW AND FERMENTED IN MINERALS OF ZEA MAYS L. DK 818
    (journalhomepage:http://chimie-biologie.ubm.ro/carpathian_journal/index.html, 2021-09-17) Adeyeye, E. I.; Olaleye, A. A.; Adesina, A. J.; Olagboye, S. A.; Ayejuyo, O. O.
    This research report dealt with proximate and mineral analyses of raw (B11), germinated (B22) and fermented (B33) maize grains from the same source. Values of dry matter, organic matter and carbohydrate were high at (g/100g): 94.2-95.3, 92.9-94.6 and 74.4-75.8 respectively. Crude protein had these values (g/100g): B11 (10.9) < B22 (13.0) < B33 (13.2). Crude fat was moderate at 5.05-5.59 g/100g. On concentration levels, the following were observed in the proximate composition: B22 > B11; B22 ≡ B33; B11 > B33. The energy from Z. mays was majorly from the carbohydrate (kcal/100g): B11 (303, 77.3%); B22 (297, 74.4%) and B33 (302, 75.5%). These minerals were generally high in the samples (mg/100g): K (550-661), Mg (220-235), P (369-401) whereas values were low for Fe, Cu, Co, Mn, Zn, Se and < 0.001 in Pb. The mineral density per sample ran thus (mg/100g): B11 (1227)< B22 (1403) > B33 (1313). On the whole, B22 > B33 >B11 as follows: B22> B11, 12/12 = 100%; B22>B33, 10/12 = 83.3%; B33 > B11, 8/12 = 66.7%. In the mineral ratios determined, only Zn/Cu values of 7.80-10.7 were close to reference balance ideal of 8.00. All the calculated mineral safety index (MSI) were lower than the standard Table values. At both proximate and mineral levels, the pairs: B11/B22, B11/B33 and B22/B33 were significantly different at r=0.01. All the index of forecasting efficiency (IFE) were high making it possible for one of the pairs to carry out the other pair metabolic functions and vice versa.
  • Item
    Open Access
    Data on macro(micro)plastics and hydrophobic organic contaminants in the Gulf of Guinea coastal psammitic beaches
    (elsevier, 2022-09-20) Benson, N.U.; Fred-Ahmadu, O. H.; Ayejuyo, O. O.
    The ubiquity of microplastics in coastal environments and marine ecosystems is a significant concern because they have a strong affinity for organic contaminants. This pa- per presents the first reported data on hydrophobic or- ganic contaminants (HOCs) and microplastics particles (MPs, 1–5 mm) in lagoon and beach sediments along the Gulf of Guinea coastline (SE Atlantic). Sampling was carried out between August and November 2019. Ten sites were designated for each location, and sediment samples were taken along three transects: high waterline, drift waterline, and current waterline. Sediment samples were extracted through density floatation procedure and sieving. Primary data on polycyclic aromatic hydrocarbons (PAHs), polychlori- nated biphenyls (PCBs), and organochlorine pesticides (OCPs) associated with MPs are provided, as well as detailed in- formation on sampling coordinates, plastic types, and their relative abundance. Refer to the research publication “Mi- croplastics and associated organic pollutants in beach sedi- ments from the Gulf of Guinea (SE Atlantic) coastal ecosys- tems”(Fred-Ahmadu et al., 2022) for detailed discussion and interpretation of the reported data.
  • Item
    Open Access
    Electrochemical Quantification of The Levels of Hydrogen Peroxide in Cassava Using Glassy Carbon Electrode Modified with Chitosan/Silver NanoHybrid
    (The Proceedings of The Nigerian Academy of Science, 2020) Akitoye, A.A; Ibrahim, G.O; Okiei, W.O
    This study correlates the production of hydrogen peroxide in cassava with its rapid postharvest physiological deterioration (PPD). Chitosan/silver nanohybrid was synthesized and immobilized on glassy carbon electrode for improved detection of hydrogen peroxide in electrochemical studies. The cathodic peak current for the reduction of hydrogen peroxide to water and oxygen occurred at -550 mV. β-carotene contents of the cassava cultivars were quantified using UV-Vis spectroscopy at a wavelength of 480 nm. No significant amount of hydrogen peroxide was found in the root tubers on the first, second, third and fourth day. However, the production of hydrogen peroxide from the different cultivars on the fifth and sixth day after harvest was found to correlate with their respective β-carotene contents. The cultivar with the highest β-carotene content (Yellow roots- IBA070593: 0.0044 mg/g) was found to have the lowest level of hydrogen peroxide on day 5 and day 6: 0.096 mmol/g FW and 0.037 mmol/g respectively; while that with the least β-carotene level (White roots- IBA980505: 0.0000 mg/g) demonstrated the highest level of hydrogen peroxide content on day 5 and day 6: 0.177 mmol/g FW and 0.096 mmol/g respectively; and highest percentage increase from the fifth to the sixth day of the PPD process. It is seen from this study that an increase in the level of hydrogen peroxide indicates PPD, and that antioxidants with hydrogen peroxide scavenging properties can help increase shelf-life of cassava cultivars. Keywords: Cassava, food security, postharvest physiological deterioration
  • Item
    Open Access
    Chemical Composition, Gastroprotective, and Antioxidant Activities of Schrebera arborea Fruits
    (Taylor and Francis, 2020-01-02) Sofidiya, M.O.; Bamigbade, O.; Basheeru, K.; Adegoke, O.; Agunbiade, FO
    The chemical composition, gastroprotective, and antioxidant activities of Schrebera arborea fruits were investigated. The solvent extracts were analyzed for fatty acid and polyphenolic content using gas chromatography-mass spectrometry (GC–MS) and high performance liquid chromatography (HPLC), respectively. Acute toxicity study was done by oral administration at 2,000 mg kg–1. Gastroprotective effect was evaluated at 50, 100, or 150 mg kg–1 in ethanol and indomethacin-induced ulcer models in rats. The antioxidant activities of the extract were also evaluated. Sitosterol (41.55%) was the major component identified by GC–MS. Quantitative HPLC analysis for phenolic compounds indicated the presence of gallic acid (0.19 mg g–1), caffeic acid (0.13 mg g–1), rutin (0.30 mg g–1), apigenin-7-glucoside (1.21 mg g–1), catechin (1.84 mg g–1), and kaempferol (6.53 mg g–1), respectively. The ethanolic extract of the fruit produced 63.5% and 80.8% inhibition of ethanol and indomethacin-induced ulcer at 100 mg kg–1, respectively. The extract at 100 mg kg–1 reduced MDA level and increased glutathione, catalase, and superoxide dismutase activities in rat stomach tissue. Significant radical scavenging antioxidant activity was recorded in vitro.
  • Item
    Open Access
    Thermodynamics of Electrochemical reaction in Lead-acid Battery
    (Faculty of Science, Lagos State University, Lagos, 2018) Akinbulu I.A. and Ogunbayo B.T.
    The quest to construct efficient and reliable electric cars can be achieved with the use of highly efficient and dependable batteries. Electric cars are projected to replace the current petrol-powered automobiles. The debilitating effects of global warming have made this task more imperative. The design of such batteries requires broad understanding of their operations; in order to optimize their outputs. The study of the thermodynamics of the electrochemical reactions occurring in these batteries offers a veritable platform to achieving this aim. In this study, thermodynamics of electrochemical reaction in a Lead-acid battery was investigated. Electromotive force (e.m.f.) of the battery, containing sulphuric acid electrolyte of known concentration, was measured at different temperatures (303, 308, 313, 318 and 323 K). Necessary thermodynamic parameters were determined from the measured e.m.fs. A negative value of change in Gibbs’ free energy, ΔG, and positive entropy change, ΔS, were obtained for the reaction. ΔG was more negative at increased temperature. The reaction was exothermic, with a negative value of enthalpy change, ΔH. A relatively small value of temperature coefficient of the electromotive force of the cell was also obtained. Values of these thermodynamic parameters indicate that reaction in the Lead-acid battery is thermodynamically feasible. Variation in the value of ΔG, with varying temperature, suggests that electrical work obtainable from the battery may be varied, by controlling temperature. Specifically, decrease in ΔG, with moderate increase in temperature, offers the prospect of enhanced efficiency, at moderately high temperature. Therefore, operation of the battery may be optimized, with an in-built temperature-control device