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Ase Hansen - One of the best experts on this subject based on the ideXlab platform.
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headspace volatile composition and oxidative storage stability of pressed marama bean Tylosema esculentum oil
Food Chemistry, 2012Co-Authors: Mette Holse, Mikael Agerlin Petersen, Gaamangwe Nehemiah Maruatona, Ase HansenAbstract:Abstract Marama bean ( Tylosema esculentum ) is an underutilised legume indigenous to the Kalahari Desert region of southern Africa. The bean has high lipid content and hence is a potential source for production of edible oil. The headspace volatile composition of freshly pressed marama bean oil was explored and the oil was further studied during 7 months of storage under different light and temperature conditions. The oxidative stability of the oil was examined by measuring peroxide value, vitamin E content and FT-IR spectra. Additionally, the headspace volatile composition of the oil was investigated during storage by use of dynamic headspace GC–MS. The results showed that marama oil is highly stable and has good natural antioxidant properties; enzymatic lipid oxidation does not take place in marama oil. Light has a greater effect on the lipid oxidation than has temperature, and hence marama oil should preferably be stored in darkness and rather at 25 °C than 35 °C. Under these conditions, the marama oil has a shelf life of at least 7 months.
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oxidative storage stability of roasted marama beans Tylosema esculentum
World Congress of Food Science & Technology, 2012Co-Authors: Mette Holse, Thomas Skov, Ase HansenAbstract:The marama bean is an underutilized traditional source of food for the indigenous population in Southern Africa such as the Herero, Tswana and Khoisan people and is mostly eaten as a snack after roasting in hot sand. The beans have a high content of protein and oil (mainly unsaturated lipid). This composition gives the marama bean a significant potential for production of various nutritious food products such as roasted beans. The aim of this study was to investigate the influence of different storage conditions on the oxidative stability of roasted marama beans. This was evaluated by packing the roasted marama beans in the presence or absence of oxygen and storing them with or without exposure to light for seven months. During the storage period, the changes in flavor related oxidation products (i.e. secondary oxidation products) were investigated. It was found that roasted marama beans should preferably be stored in darkness in bags containing a low amount of oxygen. Under these conditions the beans could be stored for at least five months without obtaining undesirable odors caused by lipid oxidation. Hexanal was found to be the limiting storage factor as it was the first volatile exceeding its odor detection threshold.
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proximate composition histochemical analysis and microstructural localisation of nutrients in immature and mature seeds of marama bean Tylosema esculentum an underutilised food legume
Food Chemistry, 2011Co-Authors: Minah Mmoni Mosele, Ase Hansen, Michael Hansen, Alexander Schulz, Helle Juel MartensAbstract:Abstract Marama bean (Tylosema esculentum) is a wild-growing legume adapted to semi-arid conditions in southern Africa. Both immature and mature seeds are used as food by locals and marama bean has potential as a crop plant. Physicochemical and histochemical methods were used to study the accumulation of nutrients and their localisation in immature and mature seeds. The immature seeds had a high content of moisture (67%) and protein (21%), and a low content of lipid (1.5%). At maturity, proteins formed spherical bodies that were embedded in a droplet lipid matrix. The mature seeds are exceptional as they have a high content of protein (32%) and lipid (40%) and no starch. Staining of polysaccharides indicated increases of pectin and cellulose during maturation, parallel with the general increase of cell wall thickness; however, lignin was absent. The content and distribution of protein, lipid and carbohydrates in immature and mature marama beans make this underutilised nutritive legume a prospective crop plant and interesting for food processing applications.
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characterisation of the arabinose rich carbohydrate composition of immature and mature marama beans Tylosema esculentum
Phytochemistry, 2011Co-Authors: Minah Mmoni Mosele, Ase Hansen, Soren Balling Engelsen, Jerome Diaz, Iben Sorensen, Peter Ulvskov, William G T Willats, Andreas Blennow, Jesper HarholtAbstract:Abstract Marama bean ( Tylosema esculentum ) is an important component of the diet around the Kalahari Desert in Southern Africa where this drought resistant plant can grow. The marama bean contains roughly 1/3 proteins, 1/3 lipids and 1/3 carbohydrates, but despite its potential as dietary supplement little is known about the carbohydrate fraction. In this study the carbohydrate fraction of “immature” and “mature” marama seeds are characterised. The study shows that the marama bean contains negligible amounts of starch and soluble sugars, both far less than 1%. The cell wall is characterised by a high arabinose content and a high resistance to extraction as even a 6 M NaOH extraction was insufficient to extract considerable amounts of the arabinose. The arabinose fraction was characterised by arabinan-like linkages and recognised by the arabinan antibody LM6 and LM13 indicating that it is pectic arabinan. Two pools of pectin could be detected; a regular CDTA (1,2-diaminocyclohexane- N , N , N ′, N ′-tetraacetic acid) or enzymatically extractable pectin fraction and a recalcitrant pectin fraction containing the majority of the arabinans, of which about 40% was unextractable using 6 M NaOH. Additionally, a high content of mannose was observed, possibly from mannosylated storage proteins.
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characterization of marama bean Tylosema esculentum by comparative spectroscopy nmr ft raman ft ir and nir
Food Research International, 2011Co-Authors: Mette Holse, Ase Hansen, Flemming H Larsen, Soren Balling EngelsenAbstract:Abstract The marama bean from Southern Africa has proven to be a source for production of various healthy food products. In order to exploit its commercial potential, it is important to know its chemical composition in more detail. In this study, marama beans from different geographical sites and harvest years were analyzed by use of infrared, near infrared, Raman, and 1H as well as 13C nuclear magnetic resonance spectroscopy. These techniques can measure single beans in a rapid and non-destructive manner. By comparative application, the qualitative composition of the marama bean was explored in detail, revealing large amounts of protein, dietary fiber and unsaturated fat. The carbohydrate fraction was largely present as pectins and a minor fraction of smaller water soluble carbohydrates were tentatively assigned to raffinose. It is characteristic that the beans do not contain starch or β-glucans and that the water soluble part of the proteins/peptides have a high content of the aromatic amino acid tyrosine.
Mette Holse - One of the best experts on this subject based on the ideXlab platform.
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headspace volatile composition and oxidative storage stability of pressed marama bean Tylosema esculentum oil
Food Chemistry, 2012Co-Authors: Mette Holse, Mikael Agerlin Petersen, Gaamangwe Nehemiah Maruatona, Ase HansenAbstract:Abstract Marama bean ( Tylosema esculentum ) is an underutilised legume indigenous to the Kalahari Desert region of southern Africa. The bean has high lipid content and hence is a potential source for production of edible oil. The headspace volatile composition of freshly pressed marama bean oil was explored and the oil was further studied during 7 months of storage under different light and temperature conditions. The oxidative stability of the oil was examined by measuring peroxide value, vitamin E content and FT-IR spectra. Additionally, the headspace volatile composition of the oil was investigated during storage by use of dynamic headspace GC–MS. The results showed that marama oil is highly stable and has good natural antioxidant properties; enzymatic lipid oxidation does not take place in marama oil. Light has a greater effect on the lipid oxidation than has temperature, and hence marama oil should preferably be stored in darkness and rather at 25 °C than 35 °C. Under these conditions, the marama oil has a shelf life of at least 7 months.
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oxidative storage stability of roasted marama beans Tylosema esculentum
World Congress of Food Science & Technology, 2012Co-Authors: Mette Holse, Thomas Skov, Ase HansenAbstract:The marama bean is an underutilized traditional source of food for the indigenous population in Southern Africa such as the Herero, Tswana and Khoisan people and is mostly eaten as a snack after roasting in hot sand. The beans have a high content of protein and oil (mainly unsaturated lipid). This composition gives the marama bean a significant potential for production of various nutritious food products such as roasted beans. The aim of this study was to investigate the influence of different storage conditions on the oxidative stability of roasted marama beans. This was evaluated by packing the roasted marama beans in the presence or absence of oxygen and storing them with or without exposure to light for seven months. During the storage period, the changes in flavor related oxidation products (i.e. secondary oxidation products) were investigated. It was found that roasted marama beans should preferably be stored in darkness in bags containing a low amount of oxygen. Under these conditions the beans could be stored for at least five months without obtaining undesirable odors caused by lipid oxidation. Hexanal was found to be the limiting storage factor as it was the first volatile exceeding its odor detection threshold.
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characterization of marama bean Tylosema esculentum by comparative spectroscopy nmr ft raman ft ir and nir
Food Research International, 2011Co-Authors: Mette Holse, Ase Hansen, Flemming H Larsen, Soren Balling EngelsenAbstract:Abstract The marama bean from Southern Africa has proven to be a source for production of various healthy food products. In order to exploit its commercial potential, it is important to know its chemical composition in more detail. In this study, marama beans from different geographical sites and harvest years were analyzed by use of infrared, near infrared, Raman, and 1H as well as 13C nuclear magnetic resonance spectroscopy. These techniques can measure single beans in a rapid and non-destructive manner. By comparative application, the qualitative composition of the marama bean was explored in detail, revealing large amounts of protein, dietary fiber and unsaturated fat. The carbohydrate fraction was largely present as pectins and a minor fraction of smaller water soluble carbohydrates were tentatively assigned to raffinose. It is characteristic that the beans do not contain starch or β-glucans and that the water soluble part of the proteins/peptides have a high content of the aromatic amino acid tyrosine.
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chemical composition of marama bean Tylosema esculentum a wild african bean with unexploited potential
Journal of Food Composition and Analysis, 2010Co-Authors: Mette Holse, Soren Husted, Ase HansenAbstract:Abstract Marama bean is an underutilized legume which grows wild in Southern Africa and forms part of the diet for the indigenous population. The seeds are rich in lipid and protein, and have the potential to improve nutrition and increase food security for people living in these rural areas. Sixteen samples of marama beans from Botswana, Namibia and South Africa harvested in 1990–2008 were examined for chemical composition. The nutrient content on dry matter basis was: protein 29–38%, lipids 32–42%, dietary fiber 19–27% and ash 2.5–3.7%. In general, beans from South Africa had higher content of protein and ash compared to beans from Botswana and Namibia. The vitamin E isomers α-, β- and γ-tocopherols were found at levels of 14–48, 1.1–3.3 and 59–234 μg/g, respectively. In general, beans from Namibia contained the highest amount of vitamin E. The marama bean had a mineral content similar to that of peanut and approaching that of soybean, and is a good source of the important trace-elements Zn and Fe. The three lignans secoisolariciresinol, lariciresinol and pinoresinol were present in the marama bean. Additionally, the marama bean did not seem to contain any of the potent allergens found in lupine and peanut, and it was not cyanogenic.
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the morama bean Tylosema esculentum a potential crop for southern africa
Advances in food and nutrition research, 2010Co-Authors: Jose C Jackson, Avrelija Cencic, Walter Chingwaru, Kwaku G Duodu, Mette Holse, Margarida Faria, Danie Jordaan, A M Hansen, Martha Kandawaschultz, S MpotokwaneAbstract:Abstract The morama bean is an underutilized leguminous oilseed native to the Kalahari Desert and neighboring sandy regions of Botswana, Namibia, and South Africa (Limpopo, North-West, Gauteng, and Northern Cape provinces), and forms part of the diet of the indigenous population in these countries. It is also known as gemsbok bean, moramaboontjie, elandboontjie, braaiboonjie, marama, marumana, tsi, tsin, gami, and ombanui. It is reported as an excellent source of good quality protein (29–39%); its oil (24–48%) is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Morama is a good source of micronutrients such as calcium, iron, zinc, phosphate, magnesium, and B vitamins including folate. It is also reported to be a potential source of phytonutrients including phenolic compounds (e.g., tannins), trypsin inhibitors, phytates, and oligosaccharides, components which have been shown in other foods to contribute to health in particular, prevention of noncommunicable diseases such as cardiovascular diseases, diabetes, and some cancers. From a nutritional and health perspective, the morama bean has potential commercial value as a cash crop and value-added products, particularly in the communities where it is found.
Jose C Jackson - One of the best experts on this subject based on the ideXlab platform.
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therapeutic and prophylactic potential of morama Tylosema esculentum a review
Phytotherapy Research, 2015Co-Authors: Ofentse Mazimba, Walter Chingwaru, Jerneja Vidmar, Petrina T Kapewangolo, Jose C JacksonAbstract:Tylosema esculentum (morama) is a highly valued traditional food and source of medicine for the San and other indigenous populations that inhabit the arid to semi-arid parts of Southern Africa. Morama beans are a rich source of phenolic acids, flavonoids, certain fatty acids, non-essential amino acids, certain phytosterols, tannins and minerals. The plant's tuber contains griffonilide, behenic acid and starch. Concoctions of extracts from morama bean, tuber and other local plants are frequently used to treat diarrhoea and digestive disorders by the San and other indigenous populations. Information on composition and bioactivity of phytochemical components of T. esculentum suggests that the polyphenol-rich extracts of the bean testae and cotyledons have great potential as sources of chemicals that inhibit infectious microorganisms (viral, bacterial and fungal, including drug-resistant strains), offer protection against certain non-communicable diseases and promote wound healing and gut health. The potential antinutritional properties of a few morama components are also highlighted. More research is necessary to reveal the full prophylactic and therapeutic potential of the plant against diseases of the current century. Research on domestication and conservation of the plant offers new hope for sustainable utilisation of the plant. Copyright © 2015 John Wiley & Sons, Ltd.
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consumers knowledge and perceptions on utilization of the morama bean Tylosema esculentum in botswana
International Journal of Consumer Studies, 2013Co-Authors: Salah E O Mahgoub, Fungi M Mthombeni, Elizabeth B Maswabi, Jose C JacksonAbstract:Morama bean (Tylosema esculentum) is one of the wild legumes that grow in some parts of the Southern African countries like Botswana, Namibia and South Africa. A descriptive survey research design was conducted to assess consumers' knowledge, perceptions and utilization of Morama bean in Botswana. A structured questionnaire was used for face to face interviews. Results indicated that a high percentage of families use Morama beans for food. Other minor uses included decoration and medicine. The majority of respondents indicated that they were unaware of the nutritional qualities of the bean and of any Morama products available in the market. However, they did indicate that they would like to see Morama bean as part of some food products in the market. Development of viable Morama bean products can play a significant role in encouraging farmers to cultivate Morama on a commercial level – a wish expressed by some respondents. However, there is a need to embark on educational programmes that are aimed at creating and increasing awareness on the importance of Morama bean and other similar uncultivated food crops. Knowledge about the role and benefits of indigenous foods in ensuring food security can help communities to utilize resources around them. The findings raised a number of issues that should be of interest to policy makers and the community as a whole. Follow-up of these findings may help in better utilization of Morama beans.
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effect of pre processing on the physico chemical properties of morama bean Tylosema esculentum milk
African Journal of Food Agriculture Nutrition and Development, 2013Co-Authors: S Mpotokwane, T Tlhong, F Mthombeni, E Gaditlhatlhelwe, O Phokoje, Jose C JacksonAbstract:Morama bean (Tylosema esculentum) is an indigenous bean of the Kalahari region of Botswana. It has high nutritional content and is believed to also contain high levels of phytonutrients. The bean is traditionally eaten roasted as a snack but there is increasing emphasis to develop other innovative high value morama products, while maintaining its healthful properties. The effect of pre-processing treatments including salt-water-blanching, sodium-bicarbonate-blanching, hot-water-blanching on the proximate composition, total solids non-fat, colour, viscosity, sediments, pH and titratable acidity of morama milk was assessed. Consumer preference of the morama milk was also studied, using a soymilk control. Milk extracts were stored at 4°C for up to 24 hours and analyses conducted using standard methods. The findings indicated that the pre-processing treatments produced significant differences (p < 0.05) in protein (1.50 ± 0.18g/100g) and carbohydrate (1.09 ± 0.94g/100g) composition of the baking soda blanched milk sample. The viscosity of the baking soda blanched milk (18.91 ± 3.38cps) was significantly higher than that of the other milk samples, while the sediments of the salt water blanched milk (14.01 ± 1.63%) was significantly higher (p < 0.05) than the others. Baking soda blanching resulted in the highest pH (7.31 ± 0.32) and lowest titratable acidity levels (0.45 ± 0.24). The hot water blanched and baking soda blanched samples were slightly darker in colour, while the baking soda blanched sample had more greenness and less yellowness characteristics than the other two samples. Baking soda blanched pre-treated morama milk was the preferred morama milk by over 85% of the consumers; they also preferred it over soymilk. This is the first reported study on the processing of morama beans into milk and it demonstrated that it was possible to process high quality and acceptable morama milk, which can be utilized as a supplement to the dairy industry. Key words : morama, milk, physico-chemical, sensory, nutrition
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Tylosema esculentum marama tuber and bean extracts are strong antiviral agents against rotavirus infection
Evidence-based Complementary and Alternative Medicine, 2011Co-Authors: Walter Chingwaru, Petrina T Kapewangolo, Jose C Jackson, Runner T Majinda, Samuel O Yeboah, Martha Kandawaschulz, Avrelija CencicAbstract:Tylosema esculentum (marama) beans and tubers are used as food, and traditional medicine against diarrhoea in Southern Africa. Rotaviruses (RVs) are a major cause of diarrhoea among infants, young children, immunocompromised people, and domesticated animals. Our work is first to determine anti-RV activity of marama bean and tuber ethanol and water extracts; in this case on intestinal enterocyte cells of human infant (H4), adult pig (CLAB) and adult bovine (CIEB) origin. Marama cotyledon ethanolic extract (MCE) and cotyledon water extract (MCW) without RV were not cytotoxic to all cells tested, while seed coat and tuber extracts showed variable levels of cytotoxicity. Marama cotyledon ethanolic and water extracts (MCE and MCW, resp.) (≥0.1 mg/mL), seed coat extract (MSCE) and seed coat water extract (MSCW) (0.01 to 0.001 mg/mL), especially ethanolic, significantly increased cell survival and enhanced survival to cytopathic effects of RV by at least 100% after in vitro co- and pre-incubation treatments. All marama extracts used significantly enhanced nitric oxide release from H4 cells and enhanced TER (Ω/cm2) of enterocyte barriers after coincubation with RV. Marama cotyledon and seed coat extracts inhibited virion infectivity possibly through interference with replication due to accumulation of nitric oxide. Marama extracts are therefore promising microbicides against RV.
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antibacterial and anticandidal activity of Tylosema esculentum marama extracts research article
South African Journal of Science, 2011Co-Authors: Walter Chingwaru, Petrina T Kapewangolo, Jose C Jackson, Runner T Majinda, Samuel O Yeboah, Martha Kandawaschulz, Gyebi Duodu, Yolandi Van Zyl, C J Schoeman, Amanda MinnaarAbstract:Bean and tuber extracts of Tylosema esculentum (marama) - an African creeping plant - were obtained using ethanol, methanol and water. Based on information that T. esculentum is used traditionally for the treatment of various diseases, the antibacterial and anticandidal effects of tuber and bean extracts were investigated. The antimicrobial activity of the extracts was tested on methicillin-resistant Staphylococcus aureus (MRSA, ATCC 6538), Mycobacterium terrae (ATCC 15755), Corynebacterium diphtheriae (clinical) and Candida albicans (ATCC 2091). We performed the broth microdilution test for the determination of the minimum inhibitory concentration (MIC) and a method to determine survival of microorganisms after in vitro co-incubation with the highest concentrations of T. esculentum extracts, followed by assessment of colony counts. Ethanol and methanol (phenolic) bean extracts exhibited higher potency against bacteria and yeast than aqueous extracts. Marama bean seed coat crude ethanolic extract (MSCE) and seed coat polyphenolic fractions, especially soluble-bound fraction (MSCIB), were highly antimicrobial against M. terrae, C. diphtheriae and C. albicans. All marama bean polyphenolic fractions, namely cotyledon acidified methanol fraction (MCAM), seed coat acidified methanol fraction (MSCAM), cotyledon insoluble-bound fraction (MCIB), seed coat insoluble-bound fraction (MSCIB), cotyledon-free polyphenolic fraction (MCFP) and seed coat free polyphenolic fraction (MSCFP) had high antimicrobial effects as shown by low respective MIC values between 0.1 mg/mL and 1 mg/mL. These MIC values were comparable to those of control antimicrobials used: amphotericin B (0.5 mg/mL) and cesfulodin (0.1 mg/mL) against C. diphtheriae, streptomycin (1.0 mg/mL) and gentamicin (0.4 mg/mL) against M. terrae, and amphotericin B (0.05 mg/mL) against C. albicans. Marama seed coat soluble-esterified fraction (MSCS) had closer activity to that of cefsulodin against M. terrae. High amounts of phenolic substances, such as gallic acid, especially in the seed coats, as well as high amounts of phytosterols, lignans, certain fatty acids and peptides (specifically protease inhibitors) in the cotyledons contributed to the observed antibacterial and anticandidal activities. Marama extracts, especially phenolic and crude seed coat extracts, had high multi-species antibacterial and anticandidal activities at concentrations comparable to that of some conventional drugs; these extracts have potential use as microbicides.
Christopher A Cullis - One of the best experts on this subject based on the ideXlab platform.
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a novel inversion in the chloroplast genome of marama Tylosema esculentum
Journal of Experimental Botany, 2017Co-Authors: Yunsoo Kim, Christopher A CullisAbstract:Tylosema esculentum (marama bean) is being developed as a possible crop for resource-poor farmers in arid regions of Southern Africa. As part of the molecular characterization of this species, the chloroplast genome has been assembled from next-generation sequencing using both Illumina and Pac-Bio data. The genome is of typical organization with a large single-copy region and a small single-copy region separated by a pair of inverted repeats and covers 161537 bp. It contains a unique inversion not present in any other legumes, even in the closest relatives for which the complete chloroplast genome is available, and two complete copies of the ycf1 gene. These data extend the range of variability of legume chloroplast genomes. The sequencing of multiple individuals has identified two different chloroplast genomes which were geographically separated. The current sampling is limited so that the extent of the intraspecific variation is still to be determined, leaving open the question of legume chloroplast genomes adapted to particular arid environments.
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developing dna barcoding matk primers for marama bean Tylosema esculentum burchell schreiber
African Journal of Biotechnology, 2012Co-Authors: M Takundwa, Percy M. Chimwamurombe, K Kunert, Christopher A CullisAbstract:DNA barcoding is based on the premise that a short standardized DNA barcoding sequence can distinguish individuals of a species because the genetic variation between species exceeds that within species. Information on genetic variation of breeding materials helps to maintain genetic diversity and sustains long term selection gain. This information is a prerequisite for the genetic improvement of any plant species for effective use of germplasm in breeding and for conservation. Marama bean [ Tylosema esculentum (Burchell) Schreiber] is found in the arid, dry parts of Southern Africa and due to the high nutrient value of the seeds and tubers, richness in protein, oil and starch, it is a potential crop for arid areas where few conventional crops can survive. The effective conservation and use of marama bean genetic resources for domestication involves investigating the extent of genetic variation. The matK gene, formerly known as orfK, is emerging as a DNA barcoding gene with potential contribution to plant molecular systematics and evolution. The gene matK, approximately 1500 base pairs (bp), is believed to code for a maturase-related protein based on structural similarities to other such genes. This gene was investigated for potential contribution in genetic variation studies of marama bean and also establishing a barcode for T. esculentum . The matK gene was amplified in marama bean and we reported herein, the first record of sequences of this gene for the species that were found to be related to other legume matK sequences deposited in GenBank. The homology found with Tylosema fassoglensis (trnK gene) and Pisum sativum (matK gene) suggests that an identical region was amplified for Tylosema esculentum . A phylogenetic tree was constructed based on the matK sequences and the results suggest that the matK region can also be used in determining levels of genetic variation and for barcoding. Key words : Marama bean, DNA barcoding, genetic variation, maturase kinase.
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determining genetic diversity based on ribosomal intergenic spacer length variation in marama bean Tylosema esculentum from the omipanda area eastern namibia
African Journal of Plant Science, 2010Co-Authors: E Nepolo, Christopher A Cullis, P M Chimwamurombe, M A KandawaschulzAbstract:Marama bean [Tylosema esculentum (Burchell) L. Schreiber] is an under-utilized non-nodulating legume, native to the arid and semi-arid areas of Southern Africa, including Namibia, South Africa and Botswana. Its primary benefit to man is based upon the high nutritional value of the seeds. The protein content is slightly higher than that of soybeans and the oil content is twice that of soybeans and approaches that of peanuts. There is an increasing interest in its cultivation, due to its potential as a cash crop and food source, especially in the face of climate changes. In this study, the intergenic spacers (IGS) region of the large ribosomal DNA gene was amplified to assess length variation in Marama bean. A pair of primers based in the conserved ribosomal DNA coding region, but both reading out the coding region, was used to amplify the IGS that separates the repeat units within the tandem arrays of the ribosomal DNA (rDNA) genes. A total of 79 scorable bands were generated by the primer pair used, of which 7 alleles were polymorphic. The rDNA genes proved to be a useful tool for identifying the genetic variation of Marama bean which will be the basis of its effective domestication. Key words: Marama bean genetic diversity, rDNA gene, intergenic spacer,Tylosema esculentum.
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isolation and characterization of microsatellite repeats in marama bean Tylosema esculentum
African Journal of Agricultural Research, 2010Co-Authors: M Takundwa, Percy M. Chimwamurombe, K Kunert, Christopher A CullisAbstract:Marama bean [Tylosema esculentum (Burchell) Schreiber] occurs naturally in arid and dry parts of Southern Africa, including Botswana, Namibia and South Africa. Due to the high nutrient value of the seeds and tubers, rich in protein, oil and starch, it is a potential crop for arid areas where few conventional crops can survive. The objectives of this study were to design microsatellite primers based on microsatellite repeats identified in Marama bean and to determine their ability to detect polymorphisms for use in diversity characterization. DNA fragments of T. esculentum containing microsatellite loci were isolated by enrichment of genomic DNA by a modified FIASCO technique and sequenced. Nine Marama bean microsatellite libraries enriched for (AAG)7, (GTT)7, (AGG)7, (GAG)7, (CA)10, (CT)10, (TCC)7, (CA)15 and (CAC)7 were created and thirty microsatellite primers based on the microsatellite regions of marama bean were designed and screened for polymorphism. Polymorphic microsatellites that were identified can be used as markers in future breeding programs. The screening for the polymorphic SSRs is being carried out to reach a target of 50 or more polymorphic SSR markers. It appears that the marama bean germplasm has abundant polymorphic microsatellites as 77% of the 30 loci screened initially were polymorphic. Key words: Marama bean, microsatellite markers, primers, polymorphism, maker assisted selection (MAS).
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a review of geographical distribution of marama bean Tylosema esculentum burchell schreiber and genetic diversity in the namibian germplasm
African Journal of Biotechnology, 2009Co-Authors: E Nepolo, M Takundwa, Christopher A Cullis, P M Chimwamurombe, K KunertAbstract:Marama bean [Tylosema esculentum (Burchell) Schreiber] occurs naturally in the drier areas of Southern Africa, including Botswana and Namibia. The implementation of molecular breeding is important to advance the process of securing the world’s food supply. The development of molecular markers is vital for mapping important traits that can then be followed in subsequent breeding programs. This study assessed the distribution of marama bean in Namibia and isolated microsatellite regions for microsatellite primer design for the purpose of determining genetic diversity and construction of molecular genetic maps for marama. This will greatly enhance the process of domesticating marama bean, currently a wild plant that is still picked wild and unsustainably. The geographical distribution was geo-referenced using Geographic Positioning System (GPS) points and microsatellites were isolated from the germplasm using a modified FIASCO technique. The study revealed widespread, but patchy distribution of marama bean in Namibia. Five Marama bean microsatellite enriched libraries were created. The initial results provided vital information for the ongoing marama bean conservation function and improvement program.
Kwaku G Duodu - One of the best experts on this subject based on the ideXlab platform.
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sensory and physicochemical analyses of roasted marama beans Tylosema esculentum burchell a schreiber with specific focus on compounds that may contribute to bitterness
Food Chemistry, 2015Co-Authors: Patricia Nyembwe, Amanda Minnaar, Kwaku G Duodu, Henrietta Letitia De KockAbstract:The role of phenolics and saponins in contributing to bitterness in marama beans, an underutilized legume, especially when roasted, was investigated. Marama beans were roasted at 150°C for 20, 25 or 30 min, then dehulled to separate cotyledons, and pastes were prepared from these. Water extracts were prepared from full fat and defatted flours from roasted and unroasted marama cotyledons. A sensory panel evaluated the sensory attributes of marama pastes and water extracts. Marama water extracts were analysed for total phenolic content, phenolic composition and saponin content. Roasting of marama beans for more than 20 min resulted in negative properties, such as bitterness. The major extractable phenolic acids present in marama water extracts were gallic and protocatechuic acids which increased as a function of roasting time. Saponin content of the water extracts was in the range of 55-63 mg/l. The identified phenolic acids, saponins and other as yet unidentified compounds may contribute to the perceived bitterness.
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characterisation of phenolic acids flavonoids proanthocyanidins and antioxidant activity of water extracts from seed coats of marama bean Tylosema esculentum an underutilised food legume
International Journal of Food Science and Technology, 2012Co-Authors: Jeremiah S Shelembe, Duncan Cromarty, Megan Jean Bester, Amanda Minnaar, Kwaku G DuoduAbstract:The EU for supporting this work through the EU FP-grant (FP6-2004- INCO-DEV-3-MARAMA II-032059), Development of Innovative and Healthful Marama bean (Tylosema esculentum) Products Targeting Niche Markets (http:// www.marama.life.ku.dk/).
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the morama bean Tylosema esculentum a potential crop for southern africa
Advances in food and nutrition research, 2010Co-Authors: Jose C Jackson, Avrelija Cencic, Walter Chingwaru, Kwaku G Duodu, Mette Holse, Margarida Faria, Danie Jordaan, A M Hansen, Martha Kandawaschultz, S MpotokwaneAbstract:Abstract The morama bean is an underutilized leguminous oilseed native to the Kalahari Desert and neighboring sandy regions of Botswana, Namibia, and South Africa (Limpopo, North-West, Gauteng, and Northern Cape provinces), and forms part of the diet of the indigenous population in these countries. It is also known as gemsbok bean, moramaboontjie, elandboontjie, braaiboonjie, marama, marumana, tsi, tsin, gami, and ombanui. It is reported as an excellent source of good quality protein (29–39%); its oil (24–48%) is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Morama is a good source of micronutrients such as calcium, iron, zinc, phosphate, magnesium, and B vitamins including folate. It is also reported to be a potential source of phytonutrients including phenolic compounds (e.g., tannins), trypsin inhibitors, phytates, and oligosaccharides, components which have been shown in other foods to contribute to health in particular, prevention of noncommunicable diseases such as cardiovascular diseases, diabetes, and some cancers. From a nutritional and health perspective, the morama bean has potential commercial value as a cash crop and value-added products, particularly in the communities where it is found.
