Cowpea is a major staple food crop which serves as a source of protein for many Nigerians. Its production and preservation involve the application of pesticides to ensure optimum yield and prevent storage losses. The study evaluated aflatoxin and pesticide residues present in Cowpea grains obtained from retailers in major markets in six States of North Central and the Federal Capital Territory Abuja, Nigeria. The quantitative detection of pesticide residue was conducted through the use of Gas chromatography fitted with Electron Capture Detector (GC-ECD). Aflatoxin (AfB1, AfB2, AfG1 and AfG2) analysis was conducted by the use of thin layer chromatography (TLC). Twenty-three pesticide residues including organochlorine insecticides, dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), fungicide (Etridiazole, chloroneb), herbicide (Simazine, atrazine) were detected in cowpea samples. Dichlorodiphenyldichloroethylene (DDE) was present in 95% of the samples while endosulfan sulfate and endosulfan II were detected in 85% of the cowpea samples. Endrin aldehyde, DDT and DDD were the least detected. Pesticides residues in cowpea grains tested ranged from 72.67 mg kg- 1 in samples from Kogi State to 159.67 mg kg-1 in samples from Plateau State which were above the allowable limits of 20 mg kg-1. Aflatoxin was below detectable limits in all the cowpea samples analyzed. The high amount of pesticide residues in the cowpea samples poses health hazards to unsuspecting cowpea consumers.
{"title":"Assessment of aflatoxin and pesticide residue in cowpea (Vigna unguiculata L. Walp.) from North Central Nigeria","authors":"C. Ekhuemelo","doi":"10.4314/sa.v22i1.5","DOIUrl":"https://doi.org/10.4314/sa.v22i1.5","url":null,"abstract":"Cowpea is a major staple food crop which serves as a source of protein for many Nigerians. Its production and preservation involve the application of pesticides to ensure optimum yield and prevent storage losses. The study evaluated aflatoxin and pesticide residues present in Cowpea grains obtained from retailers in major markets in six States of North Central and the Federal Capital Territory Abuja, Nigeria. The quantitative detection of pesticide residue was conducted through the use of Gas chromatography fitted with Electron Capture Detector (GC-ECD). Aflatoxin (AfB1, AfB2, AfG1 and AfG2) analysis was conducted by the use of thin layer chromatography (TLC). Twenty-three pesticide residues including organochlorine insecticides, dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), fungicide (Etridiazole, chloroneb), herbicide (Simazine, atrazine) were detected in cowpea samples. Dichlorodiphenyldichloroethylene (DDE) was present in 95% of the samples while endosulfan sulfate and endosulfan II were detected in 85% of the cowpea samples. Endrin aldehyde, DDT and DDD were the least detected. Pesticides residues in cowpea grains tested ranged from 72.67 mg kg- 1 in samples from Kogi State to 159.67 mg kg-1 in samples from Plateau State which were above the allowable limits of 20 mg kg-1. Aflatoxin was below detectable limits in all the cowpea samples analyzed. The high amount of pesticide residues in the cowpea samples poses health hazards to unsuspecting cowpea consumers.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127768739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Schiff base was acquired from the reaction between 4-ethoxyaniline and 2-pyridinecarboxaldehyde using three (3) synthetic methods: 2 hours reflux in ethanol, stirring in ethanol and in an ethanol-water (1:1 v/v) mixture at ambient temperature for an hour. The synthesis of 4-ethoxyaniline-2-pyridinecarboxaldehyde Schiff base afforded dark-brown crystals with a melting point of 118-120°C. The reflux reaction in ethanol gave the highest yield of 83.5% while the reaction in ethanol and in ethanol-water (1:1 v/v) mixture at ambient temperature gave 73.0% and 43.6% yield respectively. The confirmation for the formation of a new aliphatic C=N functional group was given by the IR spectrum that showed a band at 1625cm-1 for an aliphatic C=N group; the 13C NMR spectrum that showed the presence of the imino carbon (C=N) at chemical shift 158.48ppm while the 1H NMR spectral data δ(ppm) for the compound gave a one proton singlet (HC=N-) at 8.69. The spectral data were in correlation with the predicted structure of the Schiff base.
{"title":"Two facile synthetic methods for a Schiff base from 4-ethoxyaniline and 2-pyridinecarboxaldehyde","authors":"E. Ogbonda-Chukwu, O. Abayeh, O. Achugasim","doi":"10.4314/sa.v22i1.7","DOIUrl":"https://doi.org/10.4314/sa.v22i1.7","url":null,"abstract":"The Schiff base was acquired from the reaction between 4-ethoxyaniline and 2-pyridinecarboxaldehyde using three (3) synthetic methods: 2 hours reflux in ethanol, stirring in ethanol and in an ethanol-water (1:1 v/v) mixture at ambient temperature for an hour. The synthesis of 4-ethoxyaniline-2-pyridinecarboxaldehyde Schiff base afforded dark-brown crystals with a melting point of 118-120°C. The reflux reaction in ethanol gave the highest yield of 83.5% while the reaction in ethanol and in ethanol-water (1:1 v/v) mixture at ambient temperature gave 73.0% and 43.6% yield respectively. The confirmation for the formation of a new aliphatic C=N functional group was given by the IR spectrum that showed a band at 1625cm-1 for an aliphatic C=N group; the 13C NMR spectrum that showed the presence of the imino carbon (C=N) at chemical shift 158.48ppm while the 1H NMR spectral data δ(ppm) for the compound gave a one proton singlet (HC=N-) at 8.69. The spectral data were in correlation with the predicted structure of the Schiff base.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133137016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aspergillus flavus contaminates the seeds of cowpea (Vigna unguiculata) and produces mycotoxins. This study was carried out to proffer solutions to the infection caused by A. flavus on cowpea seeds. The in vitro trial was set up using two rates (50 and 100%) of each potential control agent (mancozeb, COPMET (Copper-I-oxide + metalaxyl), and aqueous extracts of Eucalyptus and neem) and a control (0%). The botanical extracts and pesticides inhibited the fungus growth significantly (P≤0.05) at different times. Both concentrations of mancozeb gave 100% inhibition of the fungus at 24–168 hours after incubation (HAI). At 24 HAI, Eucalyptus extract (50 and 100%) completely inhibited the fungus growth similar to mancozeb. Eucalyptus extract was more effective than neem extract and COPMET throughout. Though the extracts of both botanicals inhibited the growth of A. flavus at 168 HAI, Eucalyptus (83.8-89.2%) was more potent than neem (20.3–28.4%). At 48-168 HAI, both concentrations of neem extract and COPMET had similar effect on the fungus. The early stage of the antimycotic intervention is critical to the control of the fungus. This can be achieved by dressing cowpea seeds with mancozeb or Eucalyptus. However, due to the high cost and toxicity of synthetic chemicals, Eucalyptus extract could be used as an alternative for management of the fungus or incorporated into integrated disease management programmes for A. flavus. Research on the effects of long-term storage of cowpea using these botanicals is highly admonished.
{"title":"Antimycotic effects of synthetic fungicides and plant extracts on Aspergillus flavus","authors":"E. Ndi̇fon, A. F. Lum","doi":"10.4314/sa.v22i1.26","DOIUrl":"https://doi.org/10.4314/sa.v22i1.26","url":null,"abstract":"Aspergillus flavus contaminates the seeds of cowpea (Vigna unguiculata) and produces mycotoxins. This study was carried out to proffer solutions to the infection caused by A. flavus on cowpea seeds. The in vitro trial was set up using two rates (50 and 100%) of each potential control agent (mancozeb, COPMET (Copper-I-oxide + metalaxyl), and aqueous extracts of Eucalyptus and neem) and a control (0%). The botanical extracts and pesticides inhibited the fungus growth significantly (P≤0.05) at different times. Both concentrations of mancozeb gave 100% inhibition of the fungus at 24–168 hours after incubation (HAI). At 24 HAI, Eucalyptus extract (50 and 100%) completely inhibited the fungus growth similar to mancozeb. Eucalyptus extract was more effective than neem extract and COPMET throughout. Though the extracts of both botanicals inhibited the growth of A. flavus at 168 HAI, Eucalyptus (83.8-89.2%) was more potent than neem (20.3–28.4%). At 48-168 HAI, both concentrations of neem extract and COPMET had similar effect on the fungus. The early stage of the antimycotic intervention is critical to the control of the fungus. This can be achieved by dressing cowpea seeds with mancozeb or Eucalyptus. However, due to the high cost and toxicity of synthetic chemicals, Eucalyptus extract could be used as an alternative for management of the fungus or incorporated into integrated disease management programmes for A. flavus. Research on the effects of long-term storage of cowpea using these botanicals is highly admonished.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131117060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Groundwater contamination has been a growing issue in recent times as a result of population growth, urbanization and industrialization. Groundwater is highly susceptible to impacts associated with anthropogenic activities such as the release of waste materials to the environment. The groundwater vulnerability of an area is a function of the geologic and environmental factors of the area. The purpose of the study was to determine the impact of geological and environmental factors on groundwater quality in the Ndele Area of Southern Nigeria. Estimations of groundwater flow direction and overland flow direction in the study area were used to establish the likely groundwater vulnerable areas. The water quality index of groundwater sourced from hand-dug wells and boreholes in the study area was used to appraise the groundwater quality of different locations in the area. Water Quality Index is a means of summarizing and reporting water quality in a consistent manner. The mean values of water quality index parameters evaluated revealed that the WQI of water samples sourced from hand dug wells in the lower altitudes and hydraulc head areas (mini-watershed area) were found to be 101.5, which is categorised to be "unsafe for drinking," while those of the two control locations with higher altitudes and hydraulic heads were 69.0 and 67.2, respectively, and are categorised to be "poor water quality." Water samples sourced from boreholes with average depths of 40m in the lower altitudes and hydraulic head areas (mini-watershed areas) and two control areas were found to be 39.0, 44.3, and 41.2 m respectively and categorized to be "good water quality". Thus, based on some environmental ill practices such as the use of open pit toilets, discharge of suckaway to flow with surface runoffs, and improper disposal of domestic wastes in the area, this study has revealed that groundwater at the locations with lower hydraulic heads and altitudes (mini-watershed area) is highly vulnerable. This may be attributed to the fact that lower lands and hydraulic head areas are susceptible to overland and groundwater flow; hence, infiltration and water table recharge by water from higher altitudes that contaminate groundwater in such areas.
{"title":"Geo-environmental influence on groundwater quality in Ndele, Southern Nigeria","authors":"M. Kekwaru, T. Morrison, E. Abumere","doi":"10.4314/sa.v22i1.23","DOIUrl":"https://doi.org/10.4314/sa.v22i1.23","url":null,"abstract":"Groundwater contamination has been a growing issue in recent times as a result of population growth, urbanization and industrialization. Groundwater is highly susceptible to impacts associated with anthropogenic activities such as the release of waste materials to the environment. The groundwater vulnerability of an area is a function of the geologic and environmental factors of the area. The purpose of the study was to determine the impact of geological and environmental factors on groundwater quality in the Ndele Area of Southern Nigeria. Estimations of groundwater flow direction and overland flow direction in the study area were used to establish the likely groundwater vulnerable areas. The water quality index of groundwater sourced from hand-dug wells and boreholes in the study area was used to appraise the groundwater quality of different locations in the area. Water Quality Index is a means of summarizing and reporting water quality in a consistent manner. The mean values of water quality index parameters evaluated revealed that the WQI of water samples sourced from hand dug wells in the lower altitudes and hydraulc head areas (mini-watershed area) were found to be 101.5, which is categorised to be \"unsafe for drinking,\" while those of the two control locations with higher altitudes and hydraulic heads were 69.0 and 67.2, respectively, and are categorised to be \"poor water quality.\" Water samples sourced from boreholes with average depths of 40m in the lower altitudes and hydraulic head areas (mini-watershed areas) and two control areas were found to be 39.0, 44.3, and 41.2 m respectively and categorized to be \"good water quality\". Thus, based on some environmental ill practices such as the use of open pit toilets, discharge of suckaway to flow with surface runoffs, and improper disposal of domestic wastes in the area, this study has revealed that groundwater at the locations with lower hydraulic heads and altitudes (mini-watershed area) is highly vulnerable. This may be attributed to the fact that lower lands and hydraulic head areas are susceptible to overland and groundwater flow; hence, infiltration and water table recharge by water from higher altitudes that contaminate groundwater in such areas.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134361448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Crop productivity depends to a large extent on the physicochemical properties of soil on which it is grown because the later has direct relationship to the nutrient requirements and uptake of crops. Floodplains are notable for seasonal utilization to produce crops especially fruits and vegetables for our teeming population. However, the floodplains can be affected by rainfall/storm regime in a way that can impact nutrients availability negatively. It is on this premise that this research was conducted to investigate physicochemical properties of some floodplains in Ekiti State, Nigeria to ascertain their suitability for crop production. Soil samples (0-30 cm) were collected at 5 m, 25 m and 45 m perpendicular distance to each of the three river parts at upper, middle and lower portion of the river channel. The samples were air-dried, milled, sieved and subjected to physicochemical analyses using standard methods. The ranges of the physicochemical properties are pH (5.02-7.13), electrical conductivity (34.00-571.00 μS/cm), organic matter (0.14-3.77 %), nitrogen (0.03-1.47 %), Ca2+ (0.23-4.94 cmol/kg), Mg2+ (0.15-4.64 cmol/kg), Na+ (1.20-3.62 cmol/kg), K+ (2.15-19.75 cmol/kg), Al3+ (0.41-23.02 cmol/kg), H+ (0.34-28.71 cmol/kg) and CEC (9.53-65.32 cmol/kg). In general, the floodplains are slightly acidic with low organic matter content typical of West African sub-region, sandy loam with moderate cation exchange capacity. It is recommended that the floodplains under study be treated to reduce the exchangeable sodium percentage for better crop production. The acidic soils are also recommended to be limed in order to prevent the possibility of pollutants like heavy metals from entering into the food chain. Recommendations are made to improve the soils’ physicochemical condition for increased food production.
{"title":"Assessment of physicochemical properties of some cultivated floodplains in Ekiti State, Southwest Nigeria","authors":"D. O. Akodu, A. Aiyesanmi, W. B. Tomori","doi":"10.4314/sa.v22i1.25","DOIUrl":"https://doi.org/10.4314/sa.v22i1.25","url":null,"abstract":"Crop productivity depends to a large extent on the physicochemical properties of soil on which it is grown because the later has direct relationship to the nutrient requirements and uptake of crops. Floodplains are notable for seasonal utilization to produce crops especially fruits and vegetables for our teeming population. However, the floodplains can be affected by rainfall/storm regime in a way that can impact nutrients availability negatively. It is on this premise that this research was conducted to investigate physicochemical properties of some floodplains in Ekiti State, Nigeria to ascertain their suitability for crop production. Soil samples (0-30 cm) were collected at 5 m, 25 m and 45 m perpendicular distance to each of the three river parts at upper, middle and lower portion of the river channel. The samples were air-dried, milled, sieved and subjected to physicochemical analyses using standard methods. The ranges of the physicochemical properties are pH (5.02-7.13), electrical conductivity (34.00-571.00 μS/cm), organic matter (0.14-3.77 %), nitrogen (0.03-1.47 %), Ca2+ (0.23-4.94 cmol/kg), Mg2+ (0.15-4.64 cmol/kg), Na+ (1.20-3.62 cmol/kg), K+ (2.15-19.75 cmol/kg), Al3+ (0.41-23.02 cmol/kg), H+ (0.34-28.71 cmol/kg) and CEC (9.53-65.32 cmol/kg). In general, the floodplains are slightly acidic with low organic matter content typical of West African sub-region, sandy loam with moderate cation exchange capacity. It is recommended that the floodplains under study be treated to reduce the exchangeable sodium percentage for better crop production. The acidic soils are also recommended to be limed in order to prevent the possibility of pollutants like heavy metals from entering into the food chain. Recommendations are made to improve the soils’ physicochemical condition for increased food production.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132658911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An RSM-based experimental design, mathematical modelling and statistical optimization of friction stir welding process parameters was studied. A quadratic fitting model developed from a five-leveled four-factor parametric setting predicted the Ultimate Tensile Strength (UTS) of the welded AA6061- T651 joints. Statistical analysis at 95% Confidence Interval using ANOVA validated the conformity of the developed model with experimental data and also verified the adequacy of the model for UTS prediction and optimization. Results showed that the model was statistically significant (p<0.0001) with no notable lack of fit with the four parameters and their squared terms also significant statistically. The numerical optimization resulted to an optimum UTS of 166.32MPa from rotational speed, traversing speed, tool tilt angle and axial load values of 1293.641rpm, 48.467mm/min, 1.888° and 4.720kN, respectively with a desirability of 0.944. Also, 2D contour and 3D surface plots showed that the four parameters made decreasing effects on the UTS after reaching their optimized UTS. Driving forces for high UTS were: sufficient heat generation for plastic deformation, effective material coalescence, appropriate extrusion of molten material towards the trailing edge, adequate heat and mass transfer to control grain coarsening, void and flash formations. With an SN-ratio of 45.963 and low coefficient-of-variation of 1.11%, the conformity of the predicted and adjusted regression coefficients (R²) of 0.9619 and 0.9868 respectively supported by the confirmatory test and diagnostic plots showed a strong correlation between the experimental and predicted results. These demonstrated that the developed model was sufficient for predicting and optimizing the UTS of Friction Stir Weld (FSW) AA6061T651 plates.
{"title":"Statistical modelling and optimization of FS-welded 6061-T651 Aluminum alloy","authors":"I. Uchegbulam, A. J. Tonye","doi":"10.4314/sa.v22i1.17","DOIUrl":"https://doi.org/10.4314/sa.v22i1.17","url":null,"abstract":"An RSM-based experimental design, mathematical modelling and statistical optimization of friction stir welding process parameters was studied. A quadratic fitting model developed from a five-leveled four-factor parametric setting predicted the Ultimate Tensile Strength (UTS) of the welded AA6061- T651 joints. Statistical analysis at 95% Confidence Interval using ANOVA validated the conformity of the developed model with experimental data and also verified the adequacy of the model for UTS prediction and optimization. Results showed that the model was statistically significant (p<0.0001) with no notable lack of fit with the four parameters and their squared terms also significant statistically. The numerical optimization resulted to an optimum UTS of 166.32MPa from rotational speed, traversing speed, tool tilt angle and axial load values of 1293.641rpm, 48.467mm/min, 1.888° and 4.720kN, respectively with a desirability of 0.944. Also, 2D contour and 3D surface plots showed that the four parameters made decreasing effects on the UTS after reaching their optimized UTS. Driving forces for high UTS were: sufficient heat generation for plastic deformation, effective material coalescence, appropriate extrusion of molten material towards the trailing edge, adequate heat and mass transfer to control grain coarsening, void and flash formations. With an SN-ratio of 45.963 and low coefficient-of-variation of 1.11%, the conformity of the predicted and adjusted regression coefficients (R²) of 0.9619 and 0.9868 respectively supported by the confirmatory test and diagnostic plots showed a strong correlation between the experimental and predicted results. These demonstrated that the developed model was sufficient for predicting and optimizing the UTS of Friction Stir Weld (FSW) AA6061T651 plates.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"630 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123954567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Starch extraction from Icacina senegalensis (IS) and Cyrtosperma senegalense (CS) tubers was carried out with water at room temperature. The tubers of Icacina senegalensis and Cyrtosperma senegalense gave a starch yield of 40.9% and 25.5% respectively. The amylose, amylopectin composition of starches from IS and CS tubers were determined to be 10.8%, 89.2% and 24.6%, 75.4 % respectively. The starch extracts were chemically modified to produce cross-linked, carboxymethylated and acetylated starch derivatives. The formation of new chemical bonds in the starch derivatives was confirmed with Fourier Transform Infra-red spectroscopy (FTIR). Both swelling power and gelatinization temperature of IS starch and CS starch increased with acetylation, crosslinking and carboxymethylation while the degrees of substitution for the starch derivatives ranged between 0.33 and 1.45 making the native and modified starches suitable for many industrial applications.
{"title":"Effects of acetylation, carboxymethylation and crosslinking on some physicochemical properties of starch from tubers of Icacina senegalensis and Cyrtosperma senegalense","authors":"S. I. Iweajunwa, O. Achugasim, R. Ogali","doi":"10.4314/sa.v22i1.8","DOIUrl":"https://doi.org/10.4314/sa.v22i1.8","url":null,"abstract":"Starch extraction from Icacina senegalensis (IS) and Cyrtosperma senegalense (CS) tubers was carried out with water at room temperature. The tubers of Icacina senegalensis and Cyrtosperma senegalense gave a starch yield of 40.9% and 25.5% respectively. The amylose, amylopectin composition of starches from IS and CS tubers were determined to be 10.8%, 89.2% and 24.6%, 75.4 % respectively. The starch extracts were chemically modified to produce cross-linked, carboxymethylated and acetylated starch derivatives. The formation of new chemical bonds in the starch derivatives was confirmed with Fourier Transform Infra-red spectroscopy (FTIR). Both swelling power and gelatinization temperature of IS starch and CS starch increased with acetylation, crosslinking and carboxymethylation while the degrees of substitution for the starch derivatives ranged between 0.33 and 1.45 making the native and modified starches suitable for many industrial applications.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124137970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Comparing the antioxidant activities of tomato seed oil extracted from two varieties of tomato fruits (Riogrande and Roma VF) demonstrated by five spectrophotometric methods: DPPH, β- carotene linoleic antioxidant, HRSA, ORAC, FRAP. Tomato seed is the major by-product of the tomato paste manufacturing industry in the world today. The tomato seed was extracted from healthy tomato fruits of the two varieties and were washed with water and dried in an oven at 60oC for 3 days, and milled to powder. Ten gram of the powdered samples was placed in a soxhlet extractor, using 300 ml of n- Hexane, and allowed to boil at 40-60°C for 6 hours repeatedly to obtain the oil. The oil was placed in a water bath at 70°C to remove the excess n-Hexane. The results showed that tomato seed oil (TSO) is stable, translucent and highly penetrating oil and the refractive index, Density and the specific gravity of the oil of both varieties are all in line with the FAO/WHO standard. The fatty acid composition results showed that TSO is an excellent source of essential fatty acids. Though Roma VF seed oil at a lower concentration of DPPH (43.270±0.028), β- carotene linoleic antioxidant (15.855±0.035), FRAP (10.765±0.021) and HRSA (31.010±0.014) demonstrated higher oxidation rates of scavenging free radicals, chelating prooxidative metals, quenching singlet oxygen and photosensitizers, and inactivating lipoxygenase compared to the Riogrande seed oil which had the only lower reducing potential of ORAC (1.480±0.014).
{"title":"Comparing the antioxidant activities of tomato seed oil extracted from two varieties of tomato fruits","authors":"L. Ameh, G. Obochi, S. T. Ubwa","doi":"10.4314/sa.v22i1.3","DOIUrl":"https://doi.org/10.4314/sa.v22i1.3","url":null,"abstract":"Comparing the antioxidant activities of tomato seed oil extracted from two varieties of tomato fruits (Riogrande and Roma VF) demonstrated by five spectrophotometric methods: DPPH, β- carotene linoleic antioxidant, HRSA, ORAC, FRAP. Tomato seed is the major by-product of the tomato paste manufacturing industry in the world today. The tomato seed was extracted from healthy tomato fruits of the two varieties and were washed with water and dried in an oven at 60oC for 3 days, and milled to powder. Ten gram of the powdered samples was placed in a soxhlet extractor, using 300 ml of n- Hexane, and allowed to boil at 40-60°C for 6 hours repeatedly to obtain the oil. The oil was placed in a water bath at 70°C to remove the excess n-Hexane. The results showed that tomato seed oil (TSO) is stable, translucent and highly penetrating oil and the refractive index, Density and the specific gravity of the oil of both varieties are all in line with the FAO/WHO standard. The fatty acid composition results showed that TSO is an excellent source of essential fatty acids. Though Roma VF seed oil at a lower concentration of DPPH (43.270±0.028), β- carotene linoleic antioxidant (15.855±0.035), FRAP (10.765±0.021) and HRSA (31.010±0.014) demonstrated higher oxidation rates of scavenging free radicals, chelating prooxidative metals, quenching singlet oxygen and photosensitizers, and inactivating lipoxygenase compared to the Riogrande seed oil which had the only lower reducing potential of ORAC (1.480±0.014).","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129199048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spent engine oil contaminated soil not only harbors bacteria resistant to heavy metals but also to antibiotics. This study investigated the antibiotic resistant profile of bacterial isolates from spent engine oil contaminated soil. Two soil samples one each was collected from 10 years old mechanic workshop and pristine environment. Bacteria were isolated using pour plate method. The isolates were identified based on their physiological and morphological characteristics using standard microbiological techniques. Antibiogram studies were carried out by disc diffusion method and results interpreted based on the CLSI guidelines. The isolates were identified as members of eleven genera (Bacillus, Clostridium, Pseudomonas, Rhodococcus, Klebsiella, Escherichia, Providencia, Arthrobacter, Corynebacterium, Serretia and Proteus). Results obtained revealed that all the bacterial isolates obtained from the contaminated soil exhibited antibiotics resistance, these bacterial isolates were highly resistant to cefoxatime (82.4 %) and ceftriaxone (82.4 %). Furthermore, the pristine soil isolates were highly resistant to cefoxatime (88.9 %) and ceftriaxone (88.9 %) and ceftazidime (88.9 %) these are all members of the beta-lactam class cephalosporins. The presence of antibiotics resistant bacteria in spent engine oil contaminated soil as seen in this study shows that it can be a medium of antibiotics resistance spread. Thus, stringent measures on the disposal of spent engine oil should be enforced.
{"title":"Antibiotic resistance pattern of bacteria isolated from spent engine oil contaminated soil","authors":"E. Ughala, R. C. Osaro-Matthew","doi":"10.4314/sa.v22i1.19","DOIUrl":"https://doi.org/10.4314/sa.v22i1.19","url":null,"abstract":"Spent engine oil contaminated soil not only harbors bacteria resistant to heavy metals but also to antibiotics. This study investigated the antibiotic resistant profile of bacterial isolates from spent engine oil contaminated soil. Two soil samples one each was collected from 10 years old mechanic workshop and pristine environment. Bacteria were isolated using pour plate method. The isolates were identified based on their physiological and morphological characteristics using standard microbiological techniques. Antibiogram studies were carried out by disc diffusion method and results interpreted based on the CLSI guidelines. The isolates were identified as members of eleven genera (Bacillus, Clostridium, Pseudomonas, Rhodococcus, Klebsiella, Escherichia, Providencia, Arthrobacter, Corynebacterium, Serretia and Proteus). Results obtained revealed that all the bacterial isolates obtained from the contaminated soil exhibited antibiotics resistance, these bacterial isolates were highly resistant to cefoxatime (82.4 %) and ceftriaxone (82.4 %). Furthermore, the pristine soil isolates were highly resistant to cefoxatime (88.9 %) and ceftriaxone (88.9 %) and ceftazidime (88.9 %) these are all members of the beta-lactam class cephalosporins. The presence of antibiotics resistant bacteria in spent engine oil contaminated soil as seen in this study shows that it can be a medium of antibiotics resistance spread. Thus, stringent measures on the disposal of spent engine oil should be enforced.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126124407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Okonko, J. Agu, B. J. Okonko, C.C. Ogbuji, B. O. Amadi
Dengue fever has grown to be a significant public health issue. By testing HIV-infected patients for IgM antibodies to the dengue virus, the study sought to determine its serological evidence in Port Harcourt Nigeria. Infected patients with HIV who were seen at the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Nigeria, were the subject of this cross-sectional study. A total of 94 HIV-positive patients were enlisted, and after gaining consent, approximately 5 ml of whole blood was taken. Enzyme Linked Immunosorbent Assay was used to detect the presence of IgM antibodies to the dengue fever virus (ELISA). IgM antibodies prevalence to the dengue fever virus was found to be 35.1%. Females (43.6%) had a higher prevalence. Age- wise, the group of those under 25 showed a higher prevalence (46.7%). Single people (37.9%), people with tertiary degrees (52.9%), those without jobs (42.9%), and people who live in cities (37.8%) all had higher incidence rates. Several sociodemographic characteristics and dengue fever did not differ significantly (p > 0.05), although sex (p = 0.04), employment (p = 0.02), and place of residence (p = 0.001) were statistically linked to the prevalence of dengue IgM. This study found significant serological evidence of IgM antibodies to the dengue virus, indicating that HIV-infected patients in Port Harcourt, Nigeria, were carriers of this virus. Further research on this virus is required to build on the relationship between age, marital status, education, and most importantly, the seasonal variation of the virus in terms of infection rates.
{"title":"The first serological evidence of recent dengue virus infection among HIV-infected patients attending the University of Port Harcourt Teaching Hospital, Rivers State, Nigeria","authors":"I. Okonko, J. Agu, B. J. Okonko, C.C. Ogbuji, B. O. Amadi","doi":"10.4314/sa.v22i1.1","DOIUrl":"https://doi.org/10.4314/sa.v22i1.1","url":null,"abstract":"Dengue fever has grown to be a significant public health issue. By testing HIV-infected patients for IgM antibodies to the dengue virus, the study sought to determine its serological evidence in Port Harcourt Nigeria. Infected patients with HIV who were seen at the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Nigeria, were the subject of this cross-sectional study. A total of 94 HIV-positive patients were enlisted, and after gaining consent, approximately 5 ml of whole blood was taken. Enzyme Linked Immunosorbent Assay was used to detect the presence of IgM antibodies to the dengue fever virus (ELISA). IgM antibodies prevalence to the dengue fever virus was found to be 35.1%. Females (43.6%) had a higher prevalence. Age- wise, the group of those under 25 showed a higher prevalence (46.7%). Single people (37.9%), people with tertiary degrees (52.9%), those without jobs (42.9%), and people who live in cities (37.8%) all had higher incidence rates. Several sociodemographic characteristics and dengue fever did not differ significantly (p > 0.05), although sex (p = 0.04), employment (p = 0.02), and place of residence (p = 0.001) were statistically linked to the prevalence of dengue IgM. This study found significant serological evidence of IgM antibodies to the dengue virus, indicating that HIV-infected patients in Port Harcourt, Nigeria, were carriers of this virus. Further research on this virus is required to build on the relationship between age, marital status, education, and most importantly, the seasonal variation of the virus in terms of infection rates.","PeriodicalId":166410,"journal":{"name":"Scientia Africana","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129207352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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