Ahmad Cheikhyoussef

• PhD
• Professor (Associate) at University of Namibia

Taro (Colocasia esculenta L.) is one of the underutilized roots and tuber crops that have the potential to be used as a future smart food to combat malnutrition and hunger in several parts of the world. Taro is one of the world’s oldest domesticated crops and belongs to the Araceae family, which contains 106 and 2500 genera and species, respectivel...

Kohlrabi (Brassica oleracea var. gongylodes) is a vegetable of the cruciferous family (Brassicaceae). Based on the color of kohlrabi, it is classified as purple or pale green kohlrabi. Kohlrabi by-products include mainly peels, sprouts, leaves, and seeds, with several phytochemicals being reported from these by-products, such as anthocyanin, flavon...

Cucumber (Cucumis sativus L.) is a widely cultivated plant belonging to the Cucurbitaceae family. This plant is a popular vegetable crop used in several international cuisines and traditional medicine, such as the Mediterranean diet style and Indian culture, owing to its refreshing taste, high water content, and high nutritional value. It is mainly...

Tomatoes (Solanum lycopersicum L.) are among the most valuable vegetables worldwide. This appreciation is associated with their wide varieties and unique organoleptic characteristics. The industrial processing of tomatoes generates massive amounts of by-products, mainly used in the formulation of livestock feeding material or disposed of without fu...

Mushrooms are a vital component of biologically diverse and healthy ecosystems that contains vitamins, minerals, and protein. With increasing evidence that mushrooms have medicinal effects, such as anticancer and antiviral activities, they offer great hope for various interventions in functional foods and drug development. In some cultures, mushroo...

Bacterial species causing foodborne illnesses such as Campylobacter jejuni, Clostridium botulinum, Listeria monocytogenes, Shiga toxin-producing Escherichia coli O157, Salmonella typhi, Shigella dysenteriae, and Vibrio cholerae are the main representatives of bacterial pathogens of food importance, and they pose an increasing threat to the safety a...

Despite increased awareness of the importance of consuming safe food, concerns regarding food contamination have largely been directed at exogenous chemicals in the food chain such as artificial or synthetic additives, agrochemicals, environmental contaminants, or adulterants. Comparatively, little to no attention has been directed to toxic and pot...

Fermented wine from palm trees is gaining more acceptance by consumers given its natural and health promoting attributes. The traditional wine is fermented from the extracted sap of palm trees by microbes, however, excessive contamination by spoilage microorganisms must be avoided, storage conditions must be ensured to foster its natural fermentati...

Cardamom [Elettaria cardamomum (L.) Maton] is an essential member of the Zingiberaceae family. This species has several known names, such as green cardamom, small cardamom and true cardamom. The plant is cultivated in several Asian countries; Cambodia, India, Indonesia, Nepal, Sri Lanka, North and Latin America, Mexico, Costa Rica, and African coun...

Cardamom (Elettaria cardamomum (L.) Maton) is a perennial herbaceous plant cultivated about 600 m to 1200 m above sea level in southwest India. Elettaria cardamomum has been introduced in Australia, Bangladesh, Cambodia, Costa Rica, Guatemala, Laos, Nusa Tenggara Island, Papua New Guinea, Réunion, São Tomé and Príncipe, Seychelles, Tanzania, Thaila...

Amomum subulatum (black cardamom) is the dried fruit of a perennial herbaceous plant belonging to the family Zingiberaceae. It is cultivated in marshy places across hills near water streams and is one of the major commercial crops of the Eastern Himalayan Region. It is a well-known spice with a distinct taste and aroma and is used as a flavouring a...

The aquaculture sector is growing exponentially and has certainly gained popularity in the international economics and development agenda across the world. The challenges in aquaculture intensification can be solved by establishing sustainable technologies that could boost the rapid growth rate while minimizing disease outbreaks. Host physiology is...

Clove (Syzygium aromaticum (L.) Merr. & Perry) is an essential herb with well-documented health benefits. Carbohydrates were detected in the ethanolic bud extract of S. aromaticum. Two antithrombotic polysaccharides were isolated from the flower buds of clove by anion-exchange chromatography, hydrophobic interaction column chromatography, and size...

The avocado (Persea Americana Mill.), a pear-shaped fruit, is a member of the family Lauraceae. It is a tropical native American fruit and is considered a functional food due to its unique bioactive compounds. Mexico is the largest producing country of avocado by over 30%, followed by Dominican Republic, Peru, Indonesia, Colombia, Kenya, United Sta...

Green chemistry focuses on eliminating and/or reducing the environmental pollution that protects the environment for the next generations. Green nanotechnology, one of the most important branches of green chemistry, is expected to solve the current drawbacks in different fields, including medicine, food, and the nutraceutical industries. Biocomposi...

The green synthesis of nanoparticles has been explored to develop environmentally friendly and less toxic nanomaterials that can safely incorporate into biomedical applications. Using plant extracts makes it possible to biosynthesize nanoparticles with higher biological activity attributed to the bioactive secondary metabolites’ contents of these e...

Clove (Syzygium aromaticum L.) is a dried flower bud belonging to the Myrtaceae family indigenous to Indonesia. Recently, it has been farmed in different places worldwide with potential food and nutraceutical applications. Clove volatile compounds contribute to the smell and unique aroma; meanwhile, nonvolatile compounds in the clove are mainly res...

Syzygium aromaticum (L.) Merril. & Perry commonly known as clove is an important herb with vast health benefits to human beings. S. aromaticum belongs to the Myrtaceae family and is considered one of the earliest known species for use as a spice. Clove has great potential for agricultural, cosmetic, food, and pharmaceutical applications. S. aromati...

Solar energy is one of the most important renewable and sustainable forms of energy. Different technologies have been developed to harness this free energy and contribute to the world economy, especially in countries with no seasonal variations in solar radiation. Dye-sensitized solar cells (DSSCs) are simply used to collect solar energy and conver...

Safe environment and clean energy are among the most important green chemistry fundamentals. The world economy depends mainly on fossil fuel as a source of energy, and due to limited natural resources and uncontrolled pollution, the world is looking for alternatives that can meet the basic requirements of a clean and safe life. Using alternative so...

The Opuntia, commonly known as cactus pear or prickly pear, belongs to the Cactaceae family and is widely distributed either as indigenous, alien, wild, or domesticated species in various countries across the world. Seeds are usually removed as waste products from the fruit pulp and can constitute important new oil source. The Opuntia seed oil, com...

Vegetable oils are a unique class of substances in the chemical industry, since their applications are versatile. Their contribution as solvents, cosolvents, derived solvents, reactants, or as raw materials for derived compounds is significant in the Green Chemistry field. From an economic point of view, vegetable oils are most suited as they are r...

Worldwide, bioeconomy is promoted as an ‘engine for sustainable development’. However, increasingly, the notion that ‘the bioeconomy’ will facilitate sustainable development per se is challenged. Based on the assumption that when leaving the relations between ‘nature’ and ‘society’ unquestioned, inherent inequalities are rather reproduced than over...

Seeds from berries contain between 11% and 23% oil, which can be extracted by the cold pressing method. Cold pressed berry seed oils (CPBSO) are extracted between 40°C and 60°C depending on the composition of the different seeds. CPBSO have unique characters due to their high content of polyunsaturated fatty acids (PUFAs) and low n-6/n-3 ratio (3/1...

Lepidium sativum is an annual herb, widely cultivated throughout the world as a culinary, traditional medicine, and oilseed crop. This chapter aims at providing a critical review of the physical, nutritional, and chemical properties of L. sativum seed oil. Documented information on the physical, nutritional, and chemical properties of L. sativum se...

Chia seed (Salvia hispanica L.) is widely cultivated in Latin America and Australia for its oils that are known for health-promoting characteristics due to the high content of omega-3 α-linolenic acid (ω-3 ALA) and other polyunsaturated fatty acids (PUFAs). Chia seed oil is obtained from the seed through different extraction methods, which result i...

Moringa oleifera Lam. belongs to the family Moringaceae, and is predominantly found in India and tropical and arid countries, including Namibia. The different plant parts of the tree have been subject to extensive research for many years due to the beneficial properties and applications in the medicinal, food, and fuel industries. The oil content o...

The morphological criteria of the Origanum genus divide the genus into three groups and several sections and species. There are four main groups of oregano, which are recognized for common use and economic importance: Greek, Spanish, Turkish, and Mexican oregano. The herb is an important source of active compounds and is among the most traded and c...

Supercritical carbon dioxide is predominantly becoming the solvent of choice for polymer synthesis because of several beneficial environmental and synthetic factors. It has been widely studied for use in the synthesis of polymers for a number of years, and has proven to be an effective inert solvent for polymerization reactions. Interesting progres...

Schinziophyton rautanenii (Schinz) Radcl.-Sm., formerly known as Ricinodendron rautanenii Schinz, is a large spreading dioecious tree, typically 15–20 m in height. The tree commonly grows wild in Angola, Botswana, Namibia, South Africa and Zambia and is known to be an important food source to the inhabitants. It is commonly also known as the Mongon...

Oshikundu is brewed from fermentation of pearl millet (Pennisetum glaucum (L.) R.Br) meal commonly known as mahangu, sorghum (Sorghum bicolor (L.) Moench)/pearl millet malt, water and/or bran (from pearl millet). Consumption of this brew is daily in many households mostly in the Northern Namibia. Oshikundu samples were collected from north central...

This paper examines the position, usage and healing power of medicinal plants in the treatment of mental illness in two regions in the Kavango, Namibia. It focuses in particular on three common, locally identified mental disorders, namely nyambi, kasenge, and ndjangura. These disorders are encountered in community settings and signal a breakdown in...

Moringa ovalifolia tree is indigenous to Namibia and is a multipurpose tree whose leaves, pods, fruits, and flowers are edible. The tree is well adapted to the harsh climatic conditions of the region and easily cultivated. In this paper, we investigate the physicochemical characteristics of the oil extracted from M. ovalifolia seeds collected from...

The Schinziophyton rautanenii tree is an important food source for many communities of the African continent. Oil extracted from the Manketti nut is of great economic value, due to its unique composition and properties. In this study, the physical and chemical characteristics of the oil obtained from three extraction methods - cold pressed, traditi...

Namibia has a rich biodiversity of plant species of which a great variety is used for food, cosmetics and medicinal applications. Oils from plants such as Citrullus lanatus (Kalahari melon), Schinziophyton rautanenii (Manketti) and Ximenia americana (Blue Sour plum) are produced by local people of Namibia according to age-old traditional methods fo...

In Namibia the promotion of the national bio-economy has been taken up as a strategy to facilitate sustainable and inclusive development. In order to analyse the societal-relations-to-nature characterizing the commercialization of indigenous plants, a trans-disciplinary approach is taken. Here we consider bio-prospecting negotiations not only as a...

The physicochemical characteristics, fatty acid, tocopherol, stigmasterol, β-sitosterol, and 1H NMR profiles of Citrullus lanatus and Acanthosicyos horridus melon seed oils were determined and compared among different extraction methods (cold pressing, traditional, and Soxhlet). The oil content was 40.2 ± 3.45 and 37.8 ± 7.26% for C. lanatus and A....

Bird plum (Berchemia discolor) is a shrub or tree distributed in the Arabian Peninsula and Africa characterized by edible fruits and its wood makes charcoal, building material, beehives, furniture and crafts. Berchemia discolor is also used as a dye, fodder, ornamental tree and as herbal medicine to treat several human and animal diseases and ailme...

Background: Although traditional fermented foods and beverages play an important role in contributing to the livelihoods of Namibians through enhanced food security and income generation, there is a scarcity of information regarding their traditional production methods, microbiological and biochemical characteristics, nutritional value, and safety....

A large proportion of resource poor rural households in southern African communal areas are dependent on wild edible fruits to meet part of their daily nutritional needs. For many people and ethnic groups, the use of wild edible fruits is a source of cultural identity, reflecting a deep and important body of knowledge about the environment, surviva...

In biodiversity-rich countries, the creation of new markets to finance sustainable development has become the central premise of today's environmental policy-making. In Namibia, access to traditional knowledge (TK) to be employed in commercial product development is going to be regulated under the forthcoming access and benefit-sharing (ABS) regula...

The poster presents findings of the physical and chemical properties of Namibian traditional prepared and cold pressed Sclerocarya birrea (marula/ondjove) oil.

Oshikundu or ontaku is a low- or non-alcoholic fermented drink commonly produced in over half of Namibian households on daily basis. It is prepared using water, pearl millet (Pennisetum glaucum) flour and sorghum (Sorghum bicolor) malt flour. Like many African fermented drinks, oshikundu is a dynamic drink with live fermenting microorganisms that c...

An overview of the possible ideas, solutions, food for thought to address for safety and food security in Namibia.

This paper examines the accumulation of indigenous body knowledge on primary health care among the female traditional healers in twin Kavango regions northeastern part of Namibia. The paper is grounded on one general ethno-botanical survey conducted in 2012 and ongoing ethnographic research since, 2014 on ethno botanical knowledge on medicinal plan...

Purpose The aim of this study was to evaluate the proximate composition and micronutrient content of two indigenous beverages; Maxau and Âudaï. Maxau is a maize-based fermented beverage meanwhile; Âudaï is a fermented goat’s milk. These two fermented products are traditionally produced by the Damara/Nama people in southern Namibia. There is an inad...

Purpose Oshikundu is a cereal based fermented beverage brewed from brans pearl millet (Pennisetum glaucum), locally known as “omahangu” and sorghum (Sorghum bicolor) flour. The objectives of the study were to measure the main physicochemical parameters such as titratable acidity, pH, viscosity, alcohol level and kinetics of acid evolution of oshiku...

Herbal medicines prepared from wild plants play an important role in the primary healthcare needs of people living in developing countries. A comparative ethnobotanical study was undertaken to document medicinal plants used in rural areas of Namibia and Zimbabwe. In order to document medicinal plants used for primary healthcare in rural areas of Na...

The phytochemical content and antioxidant activity of the Namibian resurrection plant, Myrothamnus flabellifolius, which is traditionally used in the management and treatment of various diseases was determined. Samples were collected from Remhoogte pass, 130 km south west of Rehoboth. Solvent extraction using ethanol, methanol, water on powdered ex...

The present study focused on the isolation, identification and antimicrobial profile of the dominant lactic acid bacteria from three traditional fermented milk products namely: Omashikwa, Mabisi and Mashini Ghamushikwa from the north-central and north-eastern parts of Namibia. The microbiological and antimicrobial activities of these products fluct...

Cereal-based fermented beverages are not only known to quench thirst but also for their biochemical contribution to human diet. One of the many fermented beverages in Namibia is Oshikundu; a cereal-based fermented non-alcoholic, brewed with water, Mahangu flour (pearl millet), sorghum flour and brans. Oshikundu is an important beverage brewed in mo...

Drawing on the ethno-botanical survey which was aimed at establishing indigenous knowledge system in Kavango region situated in the northeastern part of Namibia. This paper discusses the uses of medicinal plants by traditional healers to treat mental illness in the region. Simultaneously, method of preparation and mode of administration of these pl...

The different cultures in Namibia depend on their own indigenous foods and beverages for nutrients to sustain good health conditions. However, little is known on the food composition of their indigenous foods to the indigenous people. It is important that foods are labelled by their composition for Recommended Dietary Allowance (RDA) purposes. This...

This study focused on three traditional fermented milk products namely: Omashikwa from (Oshana, Omusati, Oshikoto and Ohangwena regions), Mabisi from Zambezi region and Mashini Ghamushikwa from Kavango region which are common in the northcentral and north-eastern of Namibia. The local fermenting microflora hence the physical and sensory of these pr...

Background Indigenous communities in Namibia possess a rich indigenous knowledge expressed within many practices of these communities. Indigenous wild edible fruits are available along the Namibian 13 regions of which it forms a rich source of vitamins, fibres, minerals and a heterogeneous collection of bioactive compounds referred to as phytochemi...

The objectives of this study were to add value to three popular indigenous fruits found in Namibia namely, Marula (Sclerocarya birrea), Monkey orange (Strychnos cocculoides) and Eembe (Berchemia discolour) into processed food products and to train rural communities on value addition for job creation, income generation and food security. Indigenous...

In recent years there has been increasing recognition by researchers, governments and development agencies That Indigenous Knowledge System (IKS) is one of the sources of knowledge which can be easily understood, accessed and useable to, particularly, people and communities in developing countries. Namibia, as a developing country is no exception i...

Fermented beverages have a long history in Africa and fermentation is the cheapest, oldest form of food preservation. Indigenous Knowledge (IK) has been at the for-front of the traditional food and beverage processing technology. Oshikundu is a Namibian cereal based fermented beverage brewed with water, brans, pearl millet (Pennisetum glaucum (L.)...

Research into Indigenous Knowledge System Technology (IKST) has been receiving increasing attention from research institutions and Government Ministries in Namibia during the last five years. Indigenous communities in Namibia possess a rich traditional knowledge expressed in many practices in their communities. This paper aims to present and identi...

This paper describes the evolution of indigenous knowledge systems documentation at the Multidisciplinary Research Centre, University of Namibia. As awareness of the value of indigenous knowledge systems has increased it has become apparent that it is threatened with extinction and there is a need to document it. Documentation of indigenous knowled...

The main objectives of this study were to document the indigenous knowledge (IK) on the Namibian traditional foods and beverages found in the Karas region between 26-29 July 2010, to collect samples of these different products for the purpose of conducting laboratory analysis to determine their nutritional profiles and to investigate the microbiolo...

Local communities in Namibia possess an in-depth knowledge of the use of medicinal plants and their environment. Medicinal plants contribute significantly to the intellectual property rights of poor local households in theses local communities. This article gives an overview of the use of indigenous knowledge held by traditional healers, the uses o...

The objective of this study was to establish a regional profile of the indigenous knowledge system (IKS) for medicinal plant use and cultural practices associated with the healing process of these plants by traditional healers in the Oshikoto region, Namibia. An ethnobotanical survey was undertaken to collect information from traditional healers du...

Ximenia is an important indigenous plant in many countries and used often in herbal preparations by traditional healers. The plant is claimed to possess medicinal properties and is used in the treatment of different ailments and diseases. The aim of this study is to report some of the medicinal properties of Ximenia used by traditional healers in O...

The aim of this study was to investigate the phytochemical properties of Eembe (Berchemia discolor); one of the underutilized indigenous plant in Namibia. This species is distributed in the northern part of Namibia and has many general uses. The fruit is high in sugar and contains vitamin C. It is eaten fresh or dried and stored for use in the dry...

A three-step purification protocol has been applied for purification of a new bacteriocin, bifidin I, from Bifidobacterium infantis BCRC 14602. The purification protocol resulted in a purification fold of 1390 with a specific activity of 365714 AU mg�1 and a yield of 25.6%. Bifidin I was recovered by adsorption–desorption onto/from silicic acid (AD...

Bifidobacterium infantis BCRC 14602 was found to produce a bacteriocin-like inhibitory substance (BLIS) with inhibitory activities against a wide range of Gram- positive and Gram-negative bacteria. An activity level of 400 AU/ml in the middle of the exponential phase (i.e. 6 h) and maximum activity (1600 AU/ml) at the beginning of the stationary ph...

The objective of this research was to compare three different methods for the isolation of bacteriocin-like inhibitory substances (BLIS) from Bifidobacterium infantis BCRC 14602 (Bioresource Collection and Research Center) for their ease of use and reliability. Ammonium sulfate with 80% saturation of the neutralized cell-free supernatant resulted i...

Antimicrobial proteinaceous compounds such as bacteriocins or bacteriocin-like compounds produced by bifidobacteria are largely unknown but have been found to have potent antimicrobial activities toward closely related bacteria and undesirable harmful microorganisms. They are useful in the fields of food preservation or safety, health care, and pha...

The aim of the study was to investigate the extracellular lipase production by the fungus, Rhizopus chinensis CCTCC M201021. The biochemical characteristics of this lipase were also identified. The inducing effect of vegetable oils (soybean oil, sunflower oil, sesame oil, rice bran oil and olive oil), fatty acids (palmitic acid, oleic acid, linolei...

 The antimicrobial activity of four strains of Bifidobacterium toward Salmonella ssp. during associated cultures growth was investigated in skim milk medium. All strains showed different degrees of antagonistic action toward the indicator strain. The highest degree of inhibition (96%) was obtained with Bifidobacterium infantis and Bifidobacteriu...

ipases (triacylglycerol acylhydrolases, E.C. 3.1.1.3) are a class of hydrolases that catalyze both, hydrolysis and synthesis of esters which are formed from glycerol and long-chain fatty acids. Lipases are potential enzymes which are used extensively in a wide range of industrial applications. The production, biochemical properties and application...

The antimicrobial effects of the supernatants obtained from four strains of bifidobacteria were tested against two types of indicator strains, Bacillus cereus and three strains of Escherichia coli. E. coli AS 1.543 was the most sensitive strain among the E. coli strains whereby B. bifidum showed the highest antimicrobial activity against indicator...