African Food Production Research Articles

SELECTED PROBLEMS OF AFRICAN AGRICULTURE AND FOOD PRODUCTION

SELECTED PROBLEMS OF AFRICAN AGRICULTURE AND FOOD PRODUCTION

Fermented fruits and legumes in Africa: production factors and health benefits

SummaryFermentation is an age‐long food processing tool used to preserve and develop functional foods and beverages. Fruits in particular have a very short shelf life due to their high water activity, favourable to microbial decomposition and spoilage, while legumes are protein‐rich crops that require improved protein digestibility. These are some standout reasons for applying this tool to develop fermented fruit‐ and legume‐based products. From multifarious fruit‐based beers, non‐alcoholic beverages and alcoholic drinks to legume‐based condiments and meals, fermentation has been used over time in Africa to enhance the food security, safety, nutrition, healthfulness and livelihoods of the people. As the nutrition and economic prospects of African fermented fruit‐ and legume‐based products are huge not only to the African continent but globally (as African diasporans and their interracial friends, spouses and relatives are notably consuming them), they are fraught with opportunities and challenges. This review describes the production factors (including raw material selection, processing techniques, environmental conditions and the role of microorganisms) and health benefits of these African fermented products. Safety concerns, fermentation challenges and other considerations are also discussed. Further studies targeting fermentation and production of novel, healthy and safer fruit‐ and legume‐based African food products are warranted due to their potential positive contribution to African and global hunger and malnutrition issues.

Climate change, flooding, and HIV transmission in Africa: Potential relationships and a call for action

AbstractThe increasing effects of climate change have intensified floods globally, especially in Africa, where millions of people live in poverty and are highly vulnerable to flooding. Climate change disproportionately affects the vulnerable, who are least equipped to handle its consequences, by exacerbating their situation. One such consequence is the potential for increased human immunodeficiency virus (HIV) transmission. Africa has been disproportionately affected by the HIV epidemic. It now faces the additional challenge of a changing climate and floods, which are capable of increasing HIV transmission in Africa through several pathways. They can force population displacement and migration, leading to the expansion of sexual networks among people living with HIV (PLWHIV). They may also create conditions conducive to the spread of other infections. Floods can cause food insecurity, which can result in various sexual behaviors that expose people to HIV infection. As global warming is linked to a decrease in African food production capacity, the effect of food insecurity on HIV may be prominent in countries where transactional sexual means is a major route of HIV transmission. Floods can also hinder the provision of HIV services, such as pre‐ and postexposure prophylaxis and antiretroviral therapy distribution, which may worsen the health outcomes of PLWHIV and promote HIV transmission, particularly in rural and remote communities. It is crucial to develop a climate‐resilient framework, including education, sustained access to HIV services, and promotion of social welfare for HIV prevention and treatment, to address the complex relationship between HIV, floods, and climate change.

Efficient agricultural practices in Africa reduce crop water footprint despite climate change, but rely on blue water resources

Alarming projections of climate change, decline in crop yields, and increased food demand constitute daunting threats to African food production and sustainable water management. Here, we map this complex water-food nexus by combining gridded climate data and process-based crop modelling to quantify scenarios of crop water footprint under Representative Concentration Pathway 2.6 and Representative Concentration Pathway 6.0 for time horizons 2040, 2070 and 2100. We show that high-input agricultural management coupled with the expansion of irrigation infrastructure could generate an average reduction of water use intensity up to 64% for staple crops, but only 5% for cash crops, by 2040. Notwithstanding the positive effect of intensification, between 82 Km3 (2040) and 102 Km3 (2100) of additional blue water will be required to sustain the increased yields. Our scenarios are suited for identifying locations where crops are subject to high climate impacts and where crop production shows trade-offs between high-input management and irrigation demand.

Less negative impacts of climate change on crop yields in West Africa in the new CMIP6 climate simulations ensemble

Food insecurity is among one of the greatest risks posed by climate change in Africa, where 90 to 95% of African food production is rainfed and a large proportion of the population already faces chronic hunger and malnutrition. Although, several studies have found robust evidence of future crop yield losses under climate change scenarios, there is wide variation among crops and regions as well as large modeling uncertainties. A large part of this uncertainty stems from climate projections, as climate models may differ in simulating future changes in precipitation and temperature, which could lead to different future crop production scenarios. This work examines the impacts of climate change on crop yields of maize, millet and sorghum in West Africa using climate change projections from the Coupled Model Intercomparison Project 5th Phase (CMIP5) and from the new generation of climate models from the Coupled Model Intercomparison Project 6th Phase (CMIP6). We use the SIMPLACE crop modeling framework to simulate historical and future crop yields, and bootstrap techniques to evaluate projected changes in crop productivity between the CMIP5 and CMIP6 ensembles. Using the new generation of climate models CMIP6, we find that the negative crop yield projections shown by CMIP5 simulations are largely reduced, with even large increases in crop yields when the effect of atmospheric CO2 concentration is considered in the crop model. These differences in crop yield impacts between the CMIP5 and CMIP6 simulations are mainly due to different climate projections of temperature and precipitation in West Africa; CMIP6 projections being significantly wetter and cooler by mid-century and to a lesser extent by the end of the century. Such results highlight the large uncertainties that remain in assessing the impacts of climate change in the region and the consequent difficulty for end-users to anticipate adaptation strategies.

Advances in Quantifying Impact and Extent of Water-Land-Food Nexus for Food Security in Africa

Food systems have the potential to promote human health and enhance environmental sustainability; yet most African countries have decadal starvation and malnourishment due to unstable food systems lacking basic nutritional profiles. To understand the key questions of the African food production and food security crisis, it is important to evaluate the past and the present balance of food production and consumption quantitatively and comprehensively and identify resource constraints. This continental study analyzed water-land-food (WLF) nexus in recent decades (1997-2017) and accessed whether these resources cope with different population growth projections, dietary changes and agricultural water management. The findings revealed that in 2017, total production in Africa for the four major crops was 83.3, 34.1, 21.0 and 26.7 million tons for, respectively, maize, rice, sorghum and wheat. Together with the imported food, 38 countries experienced an increase in kcal by food supply, while 7 countries encountered a decrease. However, only 6 countries were above the 1500 kcal∙capita−1∙day−1—the global average food consumption from the four major crops. The study also found that in the context of food production and out of the total African population, 268 million (21.6%) have enough land and water, 310 million (25.0%) is without enough land and water, further 279 million (22.5%) have enough water but not enough land, and 381 million (30.8%) encounter enough land but not enough water. This is the first WLF nexus study for the African continent and emphasizes the need for efficient and rapid changes in the food systems of the African population, both in production and consumption, in order to provide sustainable and secure food systems, and ultimately approach the first three Sustainable Development Goals.

Occurrence and Importance of Yeasts in Indigenous Fermented Food and Beverages Produced in Sub-Saharan Africa.

Indigenous fermented food and beverages represent a valuable cultural heritage in sub-Saharan Africa, having one of the richest selections of fermented food products in the world. In many of these indigenous spontaneously fermented food and beverages, yeasts are of significant importance. Several factors including raw materials, processing methods, hygienic conditions as well as the interactions between yeasts and other commensal microorganisms have been shown to influence yeast species diversity and successions. Both at species and strain levels, successions take place due to the continuous change in intrinsic and extrinsic growth factors. The selection pressure from the microbial stress factors leads to niche adaptation and both yeast species and strains with traits deviating from those generally acknowledged in current taxonomic keys, have been isolated from indigenous sub-Saharan African fermented food products. Yeasts are important for flavor development, impact shelf life, and nutritional value and do, in some cases, even provide host-beneficial effects. In order to sustain and upgrade these traditional fermented products, it is quite important to obtain detailed knowledge on the microorganisms involved in the fermentations, their growth requirements and interactions. While other publications have reported on the occurrence of prokaryotes in spontaneously fermented sub-Saharan food and beverages, the present review focuses on yeasts considering their current taxonomic position, relative occurrence and successions, interactions with other commensal microorganisms as well as beneficial effects and importance in human diet. Additionally, the risk of opportunistic yeasts is discussed.

Effect of Storage Time on Nutrient, Biodeteriorating Fungi and Aflatoxin Contents of Bitter Leaf (Vernonia amygadalina) and JUTE (Corchorus olitorius)

Unhygienic handlings of several African food products during storage have been reported to promote fungal biodeterioration and subsequent aflatoxin contamination. Therefore, this study was aimed to investigate the effect of storage time on nutrient, commonly associated bio-deteriorating fungi and aflatoxin contents of selected vegetables; Bitter leaf (Vernonia amygdalina) and Jute (Corchorus olitorius) in Nigeria. Fresh and stored vegetable samples (24) were collected from different markets in Ibadan, Nigeria, they were analyzed for proximate (% Moisture, Carbohydrate, Crude Protein, Fat and Fibre), nutrient (Potassium, Calcium, Phosphorus, Sodium Iron, Zinc and Magnesium), fungal and aflatoxin contents (AFB1, AFB2, AFG1 and AFG2). Most dominantly associated fungal strains were identified as Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Aspergillus tamari, Aspergillus parasiticus, Aspergillus fumigatus, Penicillium chrysogenum and Rhizopus nigricans. The fungal incidence was more pronounced in the stored samples as compared to the fresh samples. The storage time also significantly affected the nutrient and aflatoxin contents of the vegetables; most nutrients decreased with increasing storage period while the aflatoxin contents increased. The study affirms that the storage time has effect on the nutrient, fungal contamination and consequently on the associated aflatoxin, although the detected aflatoxin levels were below the tolerance limit but these may increase with the storage time. It is therefore advisable to take hygienic measures during storage period and also, prolong storage should be discouraged.

Engaging One Health for Non-Communicable Diseases in Africa: Perspective for Mycotoxins.

The role of mycotoxins—e.g., aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, tremorgenic toxins, and ergot alkaloids—has been recognized in the etiology of a number of diseases. In many African countries, the public health impact of chronic (indoor) and/or repeated (dietary) mycotoxin exposure is largely ignored hitherto, with impact on human health, food security, and export of African agricultural food products. Notwithstanding, African scientific research reached milestones that, when linked to findings gained by the international scientific community, make the design and implementation of science-driven governance schemes feasible. Starting from Nigeria as leading African Country, this article (i) overviews available data on mycotoxins exposure in Africa; (ii) discusses new food safety issues, such as the environment–feed–food chain and toxic exposures of food producing animals in risk assessment and management; (iii) identifies milestones for mycotoxins risk management already reached in West Africa; and (iv) points out preliminary operationalization aspects for shielding communities from direct (on health) and indirect (on trade, economies, and livelihoods) effects of mycotoxins. An African science-driven engaging of scientific knowledge by development actors is expected therefore. In particular, One health/One prevention is suggested, as it proved to be a strategic and sustainable development framework.

Organic Food Certification in South Africa: A Private Sector Mechanism in Need of State Regulation?

Organic production targets the development of a sustainable cultivation system and a variety of high-quality products with emphasis on environmental protection, biodiversity and high standards of animal protection. In South Africa, the organic sector pioneered private practices and systems in small informal groups to guide the public and private sectors on environmental and sustainability issues. A private certification system for organic products is applicable in the country consisting of network certification and third-party certification in collaboration with foreign and locally-based certification organisations. Local producers also use self-declaratory vendor claims associated with organic labels. A State auditor mechanism is nonetheless applicable with respect to the use of the term “free range” on labels for meat products. South African National Standards (SANS 1369) on Organic Agricultural Production and Processing (OAPP) have been drafted by the South African Bureau of Standards (SABS) but the final version has not yet been made public. There is presently no specific legislation on organic products in the country but draft regulations (under the Agricultural Product Standards Act) on the control and sale of organic products which have not yet been promulgated. With mainly a private organic food certification system, to what extent do South African organic food products respect rules of organic production? This paper looks into the organic food regulation in South Africa and examines how far this private sector mechanism for organic food certification is in need of State regulation.
 

Phytase-producing capacity of yeasts isolated from traditional African fermented food products and PHYPk gene expression of Pichia kudriavzevii strains

Phytate is known as a strong chelate of minerals causing their reduced uptake by the human intestine. Ninety-three yeast isolates from traditional African fermented food products, belonging to nine species (Pichia kudriavzevii, Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces marxianus, Millerozyma farinosa, Candida glabrata, Wickerhamomyces anomalus, Hanseniaspora guilliermondii and Debaryomyces nepalensis) were screened for phytase production on solid and liquid media. 95% were able to grow in the presence of phytate as sole phosphate source, P. kudriavzevii being the best growing species. A phytase coding gene of P. kudriavzevii (PHYPk) was identified and its expression was studied during growth by RT-qPCR. The expression level of PHYPk was significantly higher in phytate-medium, compared to phosphate-medium. In phytate-medium expression was seen in the lag phase. Significant differences in gene expression were detected among the strains as well as between the media. A correlation was found between the PHYPk expression and phytase extracellular activity.

Environments and trypanosomiasis risks for early herders in the later Holocene of the Lake Victoria basin, Kenya

Specialized pastoralism developed ∼3 kya among Pastoral Neolithic Elmenteitan herders in eastern Africa. During this time, a mosaic of hunters and herders using diverse economic strategies flourished in southern Kenya. It has been argued that the risk for trypanosomiasis (sleeping sickness), carried by tsetse flies in bushy environments, had a significant influence on pastoral diversification and migration out of eastern Africa toward southern Africa ∼2 kya. Elmenteitan levels at Gogo Falls (ca. 1.9-1.6 kya) preserve a unique faunal record, including wild mammalian herbivores, domestic cattle and caprines, fish, and birds. It has been suggested that a bushy/woodland habitat that harbored tsetse fly constrained production of domestic herds and resulted in subsistence diversification. Stable isotope analysis of herbivore tooth enamel (n = 86) from this site reveals, instead, extensive C4 grazing by both domesticates and the majority of wild herbivores. Integrated with other ecological proxies (pollen and leaf wax biomarkers), these data imply an abundance of C4 grasses in the Lake Victoria basin at this time, and thus little risk for tsetse-related barriers to specialized pastoralism. These data provide empirical evidence for the existence of a grassy corridor through which small groups of herders could have passed to reach southern Africa.

Philanthrocapitalism: appropriation of Africa's genetic wealth

Although debates about the Gates Foundation's Alliance for a Green Revolution in Africa (AGRA) continue with the serious criticisms that it will transform Africa's farming systems into monoculture and that it is trying to link African food production to the global ‘food value chain’, this paper focuses on more fundamental goals of AGRA: to access and privatise Africa's genetic wealth. Employing the theory of accumulation by dispossession explains why AGRA is appropriating African genetic wealth and the theory of philanthrocapitalism explains how that appropriation is occurring. This study employs philanthrocapitalism to show that the multiple acts of genetic resource expropriation are neither disparate nor unconnected, but rather, reflect a systemic change of replacing public agricultural sectors with private business practices and control.

Food safety management systems performance in African food processing companies: a review of deficiencies and possible improvement strategies

This study seeks to provide insight into current deficiencies in food safety management systems (FSMS) in African food-processing companies and to identify possible strategies for improvement so as to contribute to African countries' efforts to provide safe food to both local and international markets. This study found that most African food products had high microbiological and chemical contamination levels exceeding the set (legal) limits. Relative to industrialized countries, the study identified various deficiencies at government, sector/branch, retail and company levels which affect performance of FSMS in Africa. For instance, very few companies (except exporting and large companies) have implemented HACCP and ISO 22000:2005. Various measures were proposed to be taken at government (e.g. construction of risk-based legislative frameworks, strengthening of food safety authorities, recommend use of ISO 22000:2005, and consumers' food safety training), branch/sector (e.g. sector-specific guidelines and third-party certification), retail (develop stringent certification standards and impose product specifications) and company levels (improving hygiene, strict raw material control, production process efficacy, and enhancing monitoring systems, assurance activities and supportive administrative structures). By working on those four levels, FSMS of African food-processing companies could be better designed and tailored towards their production processes and specific needs to ensure food safety.

Genotypic characterization and safety assessment of lactic acid bacteria from indigenous African fermented food products

BackgroundIndigenous fermented food products play an essential role in the diet of millions of Africans. Lactic acid bacteria (LAB) are among the predominant microbial species in African indigenous fermented food products and are used for different applications in the food and biotechnology industries. Numerous studies have described antimicrobial susceptibility profiles of LAB from different parts of the world. However, there is limited information on antimicrobial resistance profiles of LAB from Africa. The aim of this study was to characterize 33 LAB previously isolated from three different African indigenous fermented food products using (GTG)5-based rep-PCR, sequencing of the 16S rRNA gene and species-specific PCR techniques for differentiation of closely related species and further evaluate their antibiotic resistance profiles by the broth microdilution method and their haemolytic activity on sheep blood agar plates as indicators of safety traits among these bacteria.ResultsUsing molecular biology based methods and selected phenotypic tests such as catalase reaction, CO2 production from glucose, colonies and cells morphology, the isolates were identified as Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus ghanensis, Lactobacillus plantarum, Lactobacillus salivarius, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella confusa. The bacteria were susceptible to ampicillin, chloramphenicol, clindamycin and erythromycin but resistant to vancomycin, kanamycin and streptomycin. Variable sensitivity profiles to tetracycline and gentamicin was observed among the isolates with Lb. plantarum, Lb. salivarius, W. confusa (except strain SK9-5) and Lb. fermentum strains being susceptible to tetracycline whereas Pediococcus strains and Lb. ghanensis strains were resistant. For gentamicin, Leuc. pseudomesenteroides, Lb. ghanensis and Ped. acidilactici strains were resistant to 64 mg/L whereas some W. confusa and Lb. plantarum strains had a MIC value of 16 mg/L and 32 mg/L respectively. No β-haemolytic activity was observed, however, α-haemolytic activity was observed in 27% (9) of the strains comprising Lb. salivarius (6), W. confusa (2) and Lb. delbrueckii (1) isolates.ConclusionsThe resistance to kanamycin and vancomycin is probably an intrinsic feature since similar observations were reported in the literature for LAB. Low prevalence of pathogenicity indicator traits were observed among the isolates especially with the presence of poor haemolytic activities and they could therefore be considered as interesting candidates for selection of starter cultures or probiotics for different applications.

Farm Organization, Ownership and Food Productivity In Nigeria

African food production is in crisis. Today, despite Africa’s vast physical and climatic potentials to produce food, most African States depend on food importation. Africa’s capacity to deal with its food battles is severely constrained by its political instability, its early stage of scientific and institutional development, and a rapidly changing and complex global environment. In Nigeria and in most developing economies, there is a fundamental lack of political commitment to come grips with poverty, malnutrition and access to food. Because of these barriers, traditional economics is a rather limited tool to understand food production and other related variables. Poverty, hunger, malnutrition, famine and starvation in developing economies are just as much a function of political, macroeconomic, and institutional barriers as lack of technology. Illustrations from the agrarian chaos in Sudan, Ethiopia, Somalia, Chad and others are too numerous to conclude otherwise. The aim of this paper is to determine and analyze economics incentives and strategies, which could stimulate commercial agriculture in Nigeria. The analysis is based on the premise that the form of production organization in Nigerian agriculture is the major constraint to commercialization. The paper concludes that output price subsidy is the over-riding factor in the commercialization of agriculture in Nigeria.

Wheat and gluten in South African food products

Individuals with allergies and intolerances to grain products rely on accurate food labelling to prevent potentially life-threatening reactions. The aim of this study was to evaluate a number of South African food products for gluten and wheat to ascertain whether these products may pose a risk to celiac and/or wheat allergic individuals. Twenty-five products were analysed, including spelt products, flours of buckwheat, barley, rye, rice, millet, maize, semolina, triticale, oats, porridges, rice- and maize-based cereals, and rye bread. The rye and barley flours and two oat products were shown to be contaminated with wheat. Ten out of 17 naturally gluten-free products contained gluten, although in 13 of these the levels were below 20 mg/kg. The labels of four products were found to be misleading in terms of the gluten and/or wheat claims made.

Scambi commerciali agricoli e accordi di partenariato tra Unione Europea e Africa

- The Cotonou Partnership Agreement, signed on 2000, marks the beginning of a new cooperation phase between acp countries and the eu. The iv pillar of the Agreement, aimed at the creation of a free trade area, concerns the economic and trade cooperation and is targeted to make trade in line with the wto rules and to allow the acp countries a full participation to international trade understood as strategic condition for supporting growth and development. In this context, the trade relationships between the eu and Africa are of specific importance when referred to agricultural products. The liberalization process might have a significant impact for the eu as leading world exporter and importer of agricultural goods and the wider destination and origin market of the African food and agricultural products. On the African side, agricultural export are often the primary source of foreign exchange for food imports required for domestic food security. Furthermore, the new Partnership Agreement creates an additional market access only for the agricultural products that, however, might results strongly constrained by the limited supply potential and high eu sps standards. Thus, the analysis of the costs and benefits connected to the liberalization process in both the eu and Africa is relevant for a better understanding of the forthcoming competitive scenario for the agricultural products. This is the topic of the paper that, with reference to the time period from 1995- 2006, provides a preliminary analysis of the main features of the agricultural trade flows between the eu-25 and Africa; the competitive potential of the sector; the explanatory variables of the African export flows trends to the eu-25. Despite the eu is negotiating an Agreement with the African countries as a whole, the analysis also distinguishes among geographic areas in order to estimate the likely different impact of agricultural trade liberalization. To the same aim food and agricultural product are considered separately.JEL Codes: Q17 - Agriculture in International TradeKey words: agricultural trade, trade and development, agricultural competitiveness

Isolation and PCR detection of Enterobacter sakazakii in South African food products, specifically infant formula milks

Enterobactersakazakii has recently been identified as an opportunistic pathogen. The current culture-dependent detection methods for these bacteria are time-consuming and in this study a PCR method for the detection of E. sakazakii in South African food products, including an internal amplification control (IAC) was developed. DNA was isolated and amplified from the products and they were plated on selective growth media after pre-enrichment and enrichment in Enterobacteriaceae enrichment broth. Four of the 22 products tested positive for the presence of E. sakazakii, confirmed by PCR detection and growth on selective media. The PCR method proved effective in detecting E. sakazakii in South African products after three days and could serve as an alternative for traditional microbiological techniques.

The effect of climate variation on agro-pastoral production in Africa.

Using national crop and livestock production records from 1961-2003 and satellite-derived data on pasture greenness from 1982-2003 we show that the productivity of crops, livestock, and pastures in Africa is predictably associated with the El Niño Southern Oscillation and the North Atlantic Oscillation. The causal relations of these results are partly understandable through the associations between the atmospheric fluctuations and African rainfall. The range of the explained among-year variation in crop production in Africa as a whole corresponds to the nutritional requirements for approximately 20 million people. Results suggest reduced African food production if the global climate changes toward more El Niño-like conditions, as most climate models predict. Maize production in southern Africa is most strongly affected by El Niño events. Management measures include annual changes in crop selection and storage strategies in response to El Niño Southern Oscillation-based and North Atlantic Oscillation-based predictions for the next growing season.