Evaluation of ethanol production from pito mash using Zymomonas mobilis and Saccharomyces cerevisiae

This study investigated the potential of pito mash (waste from sorghum brewing) as alternative and cost-effective feedstock for bioethanol production by means of fermentation using Zymomonas mobilis and Saccharomyces cerevisiae isolated from freshly tapped palm wine. Fermentation parameters such as pH, temperature and incubation period were studied. The fermentation microbes, Z. mobilis and S. cerevisiae were identified using APITM test kit and morphological characteristics, respectively. Analysis of reducing sugar residue was performed using dinitrosalicylic acid (DNS) method, while analysis of ethanol content was performed using gas chromatography. Pito mash recorded total starch content of 6.69%, reducing sugar content of 11.1 mg ml-1 and cellulose content of 0.41 mg g-1. Saccharification by malting increased reducing sugar content by 77.9% (19.75 mg ml-1). The optimum fermentation conditions (pH, temperature and incubation period) for Z. mobilis and S. cerevisiae were 5.5, 35°C, 3 days and 6.0, 30°C, 4 day, respectively. The maximum ethanol yield of 3.03 g l-1 and efficiency of 62% were obtained for S. cerevisiae while yield of 3.63 g l-1 and efficiency of 74.2% were obtained for Z. mobilis. Z. mobilis conclusively may be better organism for ethanol production from pito mash.Keywords: Pito mash, agro-industrial wastes, Zymomonas mobilis, ethanol, reducing sugar

Roasting effects on phenolic content and free-radical scavenging activities of pulp preconditioned and fermented cocoa (Theobroma cacao) beans

Polyphenols are phytochemicals responsible for the astringency, bitterness, green flavours and antioxidant activities in Theobroma cacao beans. Polyphenols degradation in cocoa beans during roasting is crucial to the flavour outcome and it is influenced by factors such as temperature, time and pod storage. Antioxidants are compounds that help to inhibit oxidation reactions caused by free radicals such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals and peroxynitrite thereby preventing damage to the cells and tissues. Their mechanisms of action include scavenging reactive oxygen and decreasing localised oxygen concentration thereby reducing molecular oxygen’s oxidation potential, metabolising lipid peroxides to non-radical products and chelating metal ions to prevent generation of free radicals in humans. The study aimed at investigating changes in total polyphenols, anthocyanins, o-diphenols and antioxidant activity (free-radical scavenging activities) after roasting of pulp preconditioned and fermented cocoa beans using standard analytical methods. A 4×4 full factorial design with the principal experimental factors as pod storage time (0, 3, 7 and 10 days) and roasting duration (0, 15, 30 and 45 minutes) at 120oC were used to study the changes in the total polyphenols, anthocyanins, o-diphenols and % free-radical scavenging activities of the cocoa beans. Variable decrease in total polyphenols, odiphenols and anthocyanins were observed with increase in pre-conditioning (pod storage time) and roasting duration. However, variable trends were observed for the % free-radical scavenging activities. The total polyphenols, anthocyanins and o-diphenols in the cocoa beans after 45 minutes roasting decreased in the range 132.24 to 57.17 mg/g, 6.71 to 1.07 mg/kg and 15.94 to 8.25 mg/g respectively at all pod storage treatments. The total polyphenols of the fermented, dried and unstored (freshly harvested) cocoa beans was 132.25 mg/g which reduced to 122.14 mg/g (7.6% degradation), 116.721 mg/g (11.7% degradation) and 92.22 mg/g (30.3% degradation) after storage for 3, 7 and 10 days, respectively. The optimum decrease in the % freeradical scavenging activity was 7 days and above of pods storage. Increasing roasting time caused a continuous decrease in the % free-radical scavenging activity from 89.10% to 74.31% after 45 minutes for beans from the unstored (freshly harvested) pods. However, pod storage caused an increase in the % free radical scavenging activities during roasting. Pulp pre-conditioning (pod storage) and roasting duration could be used to reduce the astringency and bitterness caused by polyphenols, o-diphenols and anthocyanins in cocoa beans as well as increase the antioxidant activity imparted by cocoa.Key words: Cocoa, pod storage, roasting, polyphenols

British ‘Colonial governmentality’: slave, forced and waged worker policies in colonial Nigeria, 1896–1930

“This is an Accepted Manuscript of an article published by Taylor & Francis in Management & Organizational History on 22 Apr 2019, available online: https://doi.org/10.1080/17449359.2019.1578669

Evaluation Of Coconut-Citrus Intercropping Systems In The Context Of Lethal Yellowing Disease Of Coconut In Ghana

Global coconut production is under the devastating threat of lethal yellowing diseases endemic in East and West Africa. The most practical solution to the disease problem lies in the development of resistant or tolerant coconut planting materials. Malayan Yellow Dwarf (MYD) crossed (x) Vanuatu Tall (VTT) coconut hybrid was identified in a resistance screening work to have moderate tolerance to the disease. Consequently, the hybrid was recommended for replanting of coconut fields devastated by lethal yellowing in Ghana. To stimulate a greater replanting effort however, there was the need to develop a more efficient coconut intercropping systems involving other economic tree crops that are capable of providing insurance against total crop failure and loss of income since the MYD x VTT coconut hybrid was only moderately tolerant to lethal yellowing. Four cropping systems involving the tolerant MYD x VTT coconut hybrid and Late Valencia sweet orange were evaluated in a randomized complete block design with three replicates. The cropping systems were: 1. Sole coconut (Coconut planted at 8.5m triangular spacing at 160 palms ha-1) 2. Sole citrus (Citrus planted at 6m square spacing at 277 trees ha-1) 3. Coconut-citrus intercrop I (Coconut planted at 9.5m triangular spacing at 128 palms ha-1 and intercropped with citrus at 100 trees ha-1) 4. Coconut-citrus intercrop II (Coconut planted at 10.5m triangular spacing at 105 palms ha-1 and intercropped with citrus at 80 trees ha-1). Citrus was planted at the convergence point of any two diagonal lines linked with four adjacent coconut palms. The MYD x VTT coconut hybrid planted at 9.5m triangular provided optimal spacing for citrus intercropping. The intercropping system did not hinder the optimal growth and yield of coconut or citrus. It enabled a more efficient use of land and generated higher productivity by fitting more trees (coconut/ citrus) to a unit area of land as compared with sole cropping. The cost-benefit ratio of the intercropping came next to sole coconut planting. Nevertheless, intercropping enjoyed 26% of fruit income as insurance against lethal yellowing disease while sole coconut planting had no insurance cover

Integrated modeling of hydrological processes and groundwater recharge based on land use land cover, and climate changes: a systematic review

Groundwater is the main available freshwater resource and therefore its use, management and sustainability are closely related to the Sustainable Development Goals (SDGs). However, Land Use Land Cover (LULC) and climate change are among the factors impacting groundwater recharge. The use of land-use and climate data in conjunction with hydrological models are valuable tools for assessing these impacts on river basins. This systematic review aimed at assessing the integrated modeling approach for evaluating hydrological processes and groundwater recharge based on LULC and climate change. The analysis is based on 200 peer-reviewed articles indexed in Scopus, and the Web of Science. Continuous research and the development of context-specific groundwater recharge models are essential to increase the long-term viability of water resources in any basin. The long-term impacts of natural and anthropogenic drivers on river basin interactions require integrating knowledge and modeling capabilities across biophysical responses, environmental problems, policies, economics, social, and data

Modeling current and future groundwater demands in the White Volta River Basin of Ghana under climate change and socio-economic scenarios

Study region: White Volta River Basin, Ghana. Study focus: Groundwater sustainability is becoming a major concern in the face of population growth, land use land cover (LULC), and climate changes. The Water Evaluation and Planning (WEAP) model is used in this study to analyse the current and future groundwater demands for the period of 2015–2070. Two Representative Concentration Pathways (RCP4.5 and RCP 8.5) scenarios from statistically downscaled fifteen CMIP5 models were combined three Shared Socioeconomic Pathways (SSPs 2,3 and 5) scenarios in the nine sub-catchments of the White Volta River Basin. New hydrological insights for the study region: The WEAP model was calibrated (2006–2012) and validated (2013–2020) using streamflow data from six gauges in five sub-catchments. The findings show that climatic change and socio-economic development will result in a disparity between groundwater supply and demand in sub-catchments with greater socioeconomic growth, especially those with higher population density and arable agricultural land. Among the basin’s nine sub-catchments, four will experience water scarcity under all future scenarios. While the groundwater flow and recharge data may be evaluated using several physical hydrological models, the calibration and validation results suggest that the current modeling approach is capable of reliably predicting future groundwater demand with associated uncertainties. The study establishes a link between climate change, socio-economic growth, and groundwater availability in the White Volta River Basin

Right Heart Catheterisation in Patients with Echocardiographic Diagnosis of Pulmonary Hypertension

Background: Anaesthetists and other clinicians depend on echocardiographic estimation of pulmonary artery pressures for clinical decisions in cardiac patients. Our objective was to compare the systolic pulmonary arterial pressures estimated by echocardiography to that measured by right heart catheterisation.Patients and Methods: This was a retrospective-prospective analytical study of all patients referred for right heart catheterisation (RHC) between 1st January 2006 and 31st March 2010. The echocardiographic (Echo) estimation of the systolic pulmonary artery pressures was compared to the systolic pulmonary artery pressures measured during right heart catheterisation.Results: There were 64 patients, 37 (57.8%) were female, 27(42.2%) male. Twenty (31.3%) were between 11-20 years and 13 (20.3%) were 31-40 years. The youngest patient was 3 years old and the oldest 68 years. The Echo diagnosis was ASD, VSD, and Pulmonary Arterial Hypertension in 32.8%, 21.9% and 12.9% respectively. The right internal jugular vein was used in 58(90.6%) and the right femoral vein in 6(9.4%). Thirty-three (51.6%) had RHC systolic pressure greater than 35mmHg. Overall there was an inaccuracy of 69.8% for pressure measured by Echo. Echo was accurate in only 31.1% of instances in patients with congenital heart disease and inaccurate in all patients with rheumatic heart disease.Conclusion: Differences exist between pressures measured by Echo and RHC. Clinically, these differences may to lead to inappropriate management of patients. RHC is therefore necessary in patients with significant pulmonary hypertension especially for congenital and rheumatic heart diseases