African Indigenous Leafy Vegetables Research Articles

Isolation and Identification of Autochthonous Lactic Acid Bacteria from Commonly Consumed African Indigenous Leafy Vegetables in Kenya

African indigenous leafy vegetables (AILVs) are plants that have been part of the food systems in Sub-Saharan Africa (SSA) for a long time and their leaves, young shoots, flowers, fruits and seeds, stems, tubers, and roots are consumed. These vegetables are high in vitamins, minerals, protein, and secondary metabolites that promote health. This study aimed at isolating, characterizing, and identifying dominant lactic acid bacteria (LAB) from naturally fermenting commonly consumed AILV in Kenya. A total of 57 LAB strains were isolated and identified based on phenotypic and 16S rRNA gene analyses from three AILVs (23 nightshade leaves, 19 cowpeas leaves, and 15 vegetable amaranth). The highest microbial counts were recorded between 48 h and 96 h of fermentation in all AILVs ranging from approximately log 8 to log 9 CFU/mL with an average pH of 3.7. Fermentation of AILVs was dominated by twenty eight Lactobacillus spp. [Lactiplantibacillus plantarum (22), Limosilactobacillus fermentum (3), Lactiplantibacillus pentosus (2) and Lactiplantibacillus casei (1)], eleven Weissella spp. (Weissella cibaria (8), W. confusa (2), and W. muntiaci) six Leuconostoc spp. [Leuconostoc mesenteroides (3), Leuc. citreum (2) and Leuc. lactis (1)], six Pediococcus pentosaceus, four Enterococcus spp. [Enterococcus mundtii (2), E. faecalis (1) and E. durans (1)] and, finally, two Lactococcus garvieae. These bacteria strains are commonly used in food fermentation as starter cultures and as potential probiotics.

Awareness and Contribution of African Indigenous Leafy Vegetables to Household Wellbeing: A Case of Smallholder Farmers in Kisii County, Kenya

This study investigated the contribution of African Indigenous Leafy Vegetables (AILVs) to the welfare of smallholder farmers in Kisii County. AILVs have recently been attracting research attention not only in terms of their inherent nutrition quality and healing properties but also for their economic potential that is brought about by increased consumer demand of these vegetables. Despite having multiple benefits and positive promise towards contributing to household food dietary quality and income, utilization of African indigenous Leafy Vegetables (AILVs) by farming households is still low as indicated by a constant deficit in supply. Based on the claimed benefits in the face of low volumes in terms of utilization, this study sought to examine the socioeconomic characteristics of AILVs smallholders and factors that influence production of these vegetables in Bomachoge Borabu Sub-County, Kisii County Kenya. A Multistage sampling method was used to obtain a sample of 150 AILV farmers. Questionnaires were used to collect the data. Descriptive statistics were used to characterize the socio-economic characteristics while Tobit model was utilized in analyzing the factors that influence production of AILVs. The Tobit regression results indicated that age, gender, education, value awareness, occupation and household income significantly influenced AILV production. The study concluded that engagement in AILVs utilization brings along unmatched benefits. The study recommends a long term campaign majorly targeting the young and the non-growing communities in creation of value awareness to improve on the utilization of the vegetables. The study also recommends a similar study in regions of the Country that record low levels of utilization.

Fermentation as a tool for increasing food security and nutritional quality of indigenous African leafy vegetables: the case of Cucurbita sp.

Sub-Saharan region is often characterized by food and nutrition insecurity especially “hidden hunger” which results from inadequate micronutrients in diets. African indigenous leafy vegetables (AILVs) can represent a valid food source of micronutrients, but they often go to waste resulting in post-harvest losses. In an attempt to prolong AILVs shelf-life while enhancing their nutritional quality, fermentation was studied from a microbiological and nutritional point of view. Pumpkin leaves (Cucurbita sp.) were spontaneously fermented using the submerged method with 3% NaCl and 3% sucrose. Controls were set up, consisting of leaves with no additions. During fermentation, samples of both treatments were taken at 0, 24, 48, 72 and 168 h to monitor pH and characterize the microbial population through culture-based and molecular-based analyses. Variations between fresh and treated leaves in B-group vitamins, carotenoids, polyphenols, and phytic acid were evaluated. Data revealed that the treatment with addition of NaCl and sucrose hindered the growth of undesired microorganisms; in controls, unwanted microorganisms dominated the bacterial community until 168 h, while in treated samples Lactobacillaceae predominated. Furthermore, the content in folate, β-carotene and lutein increased in treated leaves compared to the fresh ones, while phytic acid diminished indicating an amelioration in the nutritional value of the final product. Thus, fermentation could help in preserving Cucurbita sp. leaves, avoiding contamination of spoilage microorganisms and enhancing the nutritional values.

Fermentation of African nightshade leaves with lactic acid bacterial starter cultures

The interest in the consumption of African indigenous leafy vegetables increased in African countries, e.g. Kenya, within the last years. One example of African indigenous leafy vegetables is African nightshade (Solanum scabrum) which is nutritious, rich in proteins and micronutrients and therefore could contribute to a healthy diet. African nightshade has several agricultural advantages. However, the most important disadvantage is the fast perishability which leads to enormous post-harvest losses. In this study, we investigated the fermentation of African nightshade as a post-harvest processing method to reduce post-harvest losses. The two lactic acid bacterial starter strains Lactiplantibacillus plantarum BFE 5092 and Limosilactobacillus fermentum BFE 6620 were used to inoculate fermentations of African nightshade leaves with initial counts of 106–107 cfu/ml. Uninoculated controls were conducted for each fermentation trial. Fermentations were performed both in Kenya and in Germany. The success of the inoculated starter cultures was proven by the measurement of pH values and determination of lactic acid concentration. Lactobacilli strains dominated the microbiota of the starter inoculated samples in contrast to the non-inoculated controls. This was supported by classical culture-dependent plating on different microbiological media as well as by the culture-independent molecular biological methods denaturing gradient gel electrophoresis and 16S rRNA gene high-throughput amplicon sequencing. We could demonstrate that the use of the selected starter cultures for fermentation of African nightshade leaves led to controlled and reliable fermentations with quick acidification. Thus, controlled fermentation with appropriate starter cultures is a promising method for post-harvest treatment of African nightshade leaves.

Nutritional quality, bioactive compounds and antioxidant activity of selected African indigenous leafy vegetables as influenced by maturity and minimal processing.

The African indigenous vegetables (AIVs) are excellent sources of β-carotene, vitamin C, iron as well as protein, minerals, fiber and bioactive compounds. In the recent past, AIVs have gained commercial importance as a result of increased awareness of their nutritional and health benefits and are now produce in both formal and informal marketing channels. One of the challenges in production, marketing and consumption of AIVs is that they are highly perishable and there is inadequate capacity for their storage in fresh state. This is because most storage techniques require low temperatures, which are nonexistent for AIVs in Kenya. Minimal processing can enable AIVs produced in far flung locations to be stabilized and transported to the markets in the urban centres. However, this can affect the color, texture, flavor, and nutritional quality of AIVs. This study aimed at examining the influence of harvest maturity and minimal processing techniques on the nutritional, phytochemical and anti-oxidant capacity in stinging nettle, amaranth and black nightshade. The results indicated significant differences between treatments and stages of maturity. Results further show that the highest contents of β-carotene in fresh state, at young stage was 47.82 mg/100g in amaranth and mature stage was 71.22 mg/100g in black night shade. For vitamin C, the highest content was 142.06 mg/100g in stinging nettle at young stage while amaranth had the highest content of vitamin C at mature stage as 193.52 mg/100g. The highest phenol content in fresh state was in black night shade at 1.09 g/100g and 1.29 g/100g at young stage and mature stage respectively. Among the processed, the highest content of vitamin C was seen in Freeze-Dried Unsliced Unblanched black nightshade at both young and mature stage as 86.64mg/100g and 111.14mg/100g respectively. For β-carotene, the highest content was reported on Freeze-Dried Unsliced Blanched in amaranth as 30.24mg/100g at young stage and mature stage had 57.12mg/100g in black nightshade. Keywords: Minimal processing, blanching, drying, African indigenous vegetable, maturity Afr. J. Food Agric. Nutr. Dev . 2019; 19(3): 14769-14789

Nutritional quality, bioactive compounds and antioxidant activity of selected African indigenous leafy vegetables as influenced by maturity and minimal processing

Nutritional quality, bioactive compounds and antioxidant activity of selected African indigenous leafy vegetables as influenced by maturity and minimal processing

Water use efficiency of local amaranth as affected by timing and application methods of fertilizer micro-dosing

Previous studies conducted on fertilizer micro-dosing focused on cereals-based cropping systems and led to promising productivity results. Effort are underway to adapt the technology to other high value crops such as African indigenous leafy vegetables. The recommended hill placement method of application for cereals would not be a viable option with vegetables given their high planting density. To test the potentials of alternative application methods, a field experiment was performed in northern Benin using a randomized complete block design to evaluate the effects of five nitrogen (N) rates (0, 20, 40, 60 and 80 kg N ha(-1), respectively coded N0, N20, N40, N60 and N80), two application dates (0 (d1) and 14 (d2) days after transplanting) and three application methods (broadcast, hill and strip application) on biomass yield and water use efficiency (WUE) of local amaranth. All plots received manure (5 t ha(-1)) during bed preparation except those intended to highest level of N (N80). We found that the broadcast micro-dosing method performed equally, with the strip and hill placement application enabling to save time and labor while guarantying biomass yield and WUE. The early timing of urea application also gave equal performance like the two weeks after transplanting one, giving farmers a considerable slot of time for an effective application. In regards of the application rates, nitrogen application significantly increased biomass yield and WUE. Significantly higher biomass yield and WUE were obtained with N60. Biomass yield for N0, N20, N40 and N60 were 77, 122, 165 and 247% higher than that of N80, respectively. WUE for N0, N20, N40 and N60 were 75, 118, 161 and 236% higher than that of N80, respectively. These results suggested that broadcast micro-dosing, at transplanting of up to two weeks after transplanting, on Local amaranth is a valuable option to increase biomass yield and WUE.

Thirty-year cardiovascular risk in patients with newly diagnosed bipolar disorder and their healthy first-degree relatives

Currently, consumer eating habits have shifted to an increasing demand for high quality, safe and healthy food products worldwide. In many African countries, specifically African indigenous leafy vegetables (AIVs) gained importance in this respect contributing to human diet by providing minerals, proteins, vitamins and health-promoting antioxidant compounds. Moreover, these vegetables have an immense potential in creating job opportunities in rural as well as peri-urban areas. However, AIVs tend to suffer severe quantitative and qualitative postharvest losses because of their high perishability. UV-C has been mainly applied in sanitation and food safety for its germicidal effect but also has an impact on preventing nutritional losses. To address this, studies were conducted to evaluate the effect of postharvest application of hormic UV-C dosages on bioactive plant compounds of two AIVs, i.e. African nightshade (Solanum scabrum Mill.) cv. Olevolosi and vegetable amaranth (Amaranthus cruentus L.) cv. Madiira. Eight weeks after planting, the leaves were harvested and treated with UV-C (254 nm) at either 1.7 kJ m−2 or 3.4 kJ m−2 while untreated leaves served as control. The leaves were kept for 4 and 14 d at 20 °C (65% RH) and 5 °C (85% RH), respectively. The quality parameters studied were fresh weight loss, mineral elements (N, P, K, Ca, Mg, Fe, and Zn), protein, and structural carbohydrates determining dietary fibre content and microbial counts. In addition, antioxidative, health promoting plant compounds, i.e. carotenoid, and chlorophyll contents were evaluated. The results showed that fresh weight loss of both AIVs was significantly reduced with application of lower UV-C dosage (1.7 kJ m−2). Mineral elements and proteins were variedly affected with a general decline in the initial stages followed by an increase compared to the untreated leaves. Hemicellulose and cellulose was significantly increased in vegetable amaranth and lignin content was significantly increased in African nightshade following UV-C treatment. Chlorophyll and carotenoid contents declined within 2–4 d during storage, depending on storage conditions; but thereafter increased again significantly compared to the control. Aerobic mesophyllic and yeast counts were significantly reduced by UV-C treatment, while mould counts were not affected. The findings demonstrate the potential of using hormic UV-C for maintaining the nutritional quality of AIVs during their supply chain as an easy to apply and effective tool, hence contributing to improved food accessibility and food safety in Sub-Saharan areas such as Kenya.

X-ray fluorescence analysis of selected micronutrients in ten African indigenous leafy vegetables cultivated in Nairobi, Kenya.

IntroductionThere is a growing interest on vital roles of micronutrients in the maintenance of good health and enhancement of the immune system for prevention of diseases.MethodsEnergy dispersive X-Ray fluorescence (EDXRF) spectrometer was used for qualitative and quantitative analysis of selected micronutrients Zinc (Zn), Iron (Fe), Magnesium (Mg), Calcium (Ca) and Potassium (K) in ten African indigenous leafy vegetables (AILVs) (Corchorus olitorius, Cucurbita moschata, Amaranthus blitum, Brassica carinata , Cleome gynandra, Solanum scabrum , Crotalaria ochroleuca, Urticadioica, Manihot esculenta, Vigna unguiculata) which are cultivated, marketed and consumed in Kenya and across East and West Africa.ResultsIn this study, the highest levels of Calcium, Zinc and Iron were found in Urticadioica leaves (75.0 mg/g), Manihot esculenta leaves (0.1 mg/g) and Cucurbita moschata leaves (1.0 mg/g). Amaranthus blitum leaves exhibited the highest content of Magnesium (9.5 mg/g) and Potassium (36.5 mg/g) respectively. This study demonstrated that based on weight and bioavailabilty, 10 g of Cucurbita moschata (dried weight) provides between 57% to 136% daily value of iron for children age between 7 and 10 years old and can provide up to 41%, 81% and 27% daily value of iron for female aged 18+, lactating females aged 18+ and males aged 18+ respectively. A 10 g portion of Urticadioica leaves (dried weight) will provide 75% or 58% of the daily value of calcium based on the North American or western European recommendation respectively while the same amount of Amaranthus leaves provides between 37% to 50 % of daily value of magnesium for adults of nineteen years and older based on their weight. The daily value of zinc despite its dependency with age, weight and Zinc bioavailability can be supplied by 10 g of Manihot esculenta leaves (dried weight) at a percentage ranged from 8% to 39%. Based on the 3510 mg daily recommendation, 10 g of Amaranthus, Brassica carinata, Cleome gynandra and Cucurbita moschata (dried weight) will provide 10.4%, 10.0%, 9.8% and 9.3% daily value for potassium respectively.ConclusionThe research findings are scientific evidences of the nutritional contribution of African indigenous leafy vegetables.

Net cover color influence nutritive quality of African nightshade and spiderplant

ABSTRACTIndigenous leafy vegetables play a major role in strategies to attain food and nutritional security for African households. However, the potential of these vegetables in meeting the nutritional requirements have not been adequately exploited. This study assessed effects of shadenets on nutritive value of African indigenous leafy vegetables. The vegetables African nightshade (Solanum scabrum Mill.) and spiderplant (Cleome gynandra L.) and net covers colored white, gray, blue, and yellow, with unnetted plants as a control were used. From the 7th week after sowing (spiderplant) and transplanting (African nightshade) and at 2-week intervals nutritive quality variables were determined. Compared to open field, white net produced higher leaf β-carotene at 13 weeks after planting by 6% and 17% for African nightshade and spiderplant, respectively. Use of blue net cover reduced leaf vitamin C content by 94.5% and 79% in African nightshade and spiderplant, respectively, compared to open field at 15 weeks after planting. Higher leaf calcium was consistently recorded for plants grown under yellow net cover for African nightshade and white nets for spiderplant; but was reduced under blue net for both species on most sampling dates. Leaf iron content was maximized under yellow net cover for both crops. Use of net covers reduced leaf crude fiber content compared to open field; high leaf phenolic content was obtained in crops grown under white net for both vegetables. The crop responses were attributed to spectral quality, light intensity, and environmental changes to which the crops were subjected. The different colored agronet covers differentially influenced crop leaf nutritive quality.

Postharvest UV-C application to improve health promoting secondary plant compound pattern in vegetable amaranth

Abstract Vegetable amaranth (Amaranthus cruentus L.) is gaining importance among the African indigenous leafy vegetables (AIVs) in the diets of many households in Africa. However, improper processing, handling, and storage of AIVs often result in faster deterioration thus high quantitative and qualitative losses with reduced availability of these highly nutritive and health promoting plants. Targeted application of UV-C has been shown to induce beneficial physiological responses of crops after harvest. The present study was conducted to evaluate the effects of postharvest UV-C application on health promoting secondary plant compounds of vegetable amaranth cv. Madiira. Eight weeks after planting, leaves were harvested and treated with UV-C (254 nm) at either 1.7 kJ m−2 or 3.4 kJ m−2 while untreated leaves served as control. The leaves were kept up to 4 d and 14 d at 20 °C (65% RH) and 5 °C (85% RH), respectively. Characteristic health promoting plant compounds, such as vitamin E, carotenoids, flavonoids, phenolic acids, as well as glutathione peroxidase (GPOX) activity and antioxidant capacity (TEAC) and their correlations were analyzed. Results showed that the accumulation of secondary metabolites was dependent on UV-C dosage, storage temperature and duration. Vitamin E, carotenoids (e.g. lycopene, β-carotene and lutein), flavonoids (e.g. quercetin and kaempferol derivatives), phenolic acids (e.g. ferulic, coumaric and caffeic acid derivatives) as well as GPOX activity and TEAC increased in UV-C treated vegetable amaranth leaves compared with the untreated samples. Furthermore, there was a relationship in most studied secondary compounds and TEAC. The UV-C effects at both storage conditions were comparable for most studied compounds while storage duration variedly affected the compounds studied. The increase in the studied secondary plant compounds is attributed to their plant defense mechanism against oxidative damage of plant tissues by UV-C irradiation. This could be an important strategy in reducing the loss of secondary plant compounds, hence maintaining nutritional and health promoting properties of AIVs during postharvest supply chain.

Loss of African Indigenous Leafy Vegetables along the Supply Chain

ABSTRACTDue to high perishability, African indigenous leafy vegetables (AIVs) tend to suffer heavy postharvest loss. There is a lack of information regarding management of loss of these vegetables. This study sought to identify, and assess, types and causes of AIV loss in the supply chain. The study was done across the AIV producing location of Nakuru, Kisii, and Kakamega, in Kenya, involving 45 AIV farmers from each location. Parameters studied were socio-demographic profiles, harvesting, transportation, and marketing in relation to postharvest loss. The AIV production is primarily by women who were mainly smallholder farmers. Major problems identified were inappropriate harvesting and handling techniques, inadequate postharvest treatment and preservation methods, poor roads, lack of cold storage facilities, unhygienic market conditions, and lack of implementation by regulatory bodies on AIV handling, quality, and safety standards. Values were affected by location and supply chain stage. Yellowing, wilting, presence of foreign bodies, mechanical damage, and insect pest and disease damage were major postharvest problems along the supply chain. On average, farmers experienced loss between 10 and 50% with some experiencing >50%; this varied with location and supply stage. Short AIV shelf-life (1–2 d) is a major concern. Postharvest loss is unique for specific locations and supply chain stage, and attributed to AIV production, harvesting, handling, distribution, and marketing dynamics.

Nutritional and economic postharvest loss analysis of African indigenous leafy vegetables along the supply chain in Kenya

Over the last decade, African indigenous leafy vegetables (AIVs) such as African nightshade (Solanum scabrum Mill.) have featured increasingly in both formal and informal markets in the peri-urban and urban centres of Africa, due to the increasing awareness of their nutritive and medicinal as well as expanding economic value. AIVs are rich in nutritional and health promoting plant compounds such as vitamins, minerals, proteins, dietary fibre and antioxidant compounds. However, the crop is highly perishable and more than half of it is lost before it reaches the consumer. In Kenya, appropriate postharvest handling and treatments, storage or refrigeration facilities are lacking. More so, the information on postharvest losses of the AIVs is limited, making the management of such losses along the supply chain very difficult. The objective of the study was to determine nutritional and economic losses of African nightshade plants along the supply chain, i.e. from producer until marketing. The study was conducted in the three main commercial AIVs producing counties in Kenya, i.e. Nakuru, Kisii and Kakamega, where three farmers from each county were randomly selected. The farmers were allowed to carry out their normal routine AIVs handling procedure right from harvesting to selling; and samples were collected at each supply chain stage (at harvest, before transport, after transport and at the market). Dry matter, selected macro-nutrients (N, P, K, Ca and Mg) and micro-nutrients (Fe and Zn), protein, carotenoids and chlorophyll content, cumulative produce and economic losses as well as the causes of losses were evaluated. The results obtained revealed significant quantitative, nutritive, and economic losses of African nightshade along the supply chain. The dry matter content was reduced by between 32.8–45.5%, depending on the county, along the supply chain. The mineral elements and protein were reduced by between 3.2–29.4%, while chlorophylls and carotenoids were reduced by between 70.9–90.9% and 70.4–91.9%, respectively. Cumulative produce loss was between 71.8–292.4% while the economic loss was between 12.6–34.4%. The findings indicate the immense losses of nutritional, quantitative and economic values of African nightshade along the supply chain. Lack of certified seed varieties, unfavourable weather, inadequate postharvest handling practices and technologies as well as insect pest and diseases are the main causes of losses during the supply chain. Therefore, maintaining quality attributes and managing postharvest losses in AIVs could be among the key issues to improving food security in developing countries.

Postharvest UV-C treatment for extending shelf life and improving nutritional quality of African indigenous leafy vegetables

Currently, consumer eating habits have shifted to an increasing demand for high quality, safe and healthy food products worldwide. In many African countries, specifically African indigenous leafy vegetables (AIVs) gained importance in this respect contributing to human diet by providing minerals, proteins, vitamins and health-promoting antioxidant compounds. Moreover, these vegetables have an immense potential in creating job opportunities in rural as well as peri-urban areas. However, AIVs tend to suffer severe quantitative and qualitative postharvest losses because of their high perishability. UV-C has been mainly applied in sanitation and food safety for its germicidal effect but also has an impact on preventing nutritional losses. To address this, studies were conducted to evaluate the effect of postharvest application of hormic UV-C dosages on bioactive plant compounds of two AIVs, i.e. African nightshade (Solanum scabrum Mill.) cv. Olevolosi and vegetable amaranth (Amaranthus cruentus L.) cv. Madiira. Eight weeks after planting, the leaves were harvested and treated with UV-C (254nm) at either 1.7kJm−2 or 3.4kJm−2 while untreated leaves served as control. The leaves were kept for 4 and 14d at 20°C (65% RH) and 5°C (85% RH), respectively. The quality parameters studied were fresh weight loss, mineral elements (N, P, K, Ca, Mg, Fe, and Zn), protein, and structural carbohydrates determining dietary fibre content and microbial counts. In addition, antioxidative, health promoting plant compounds, i.e. carotenoid, and chlorophyll contents were evaluated. The results showed that fresh weight loss of both AIVs was significantly reduced with application of lower UV-C dosage (1.7kJm−2). Mineral elements and proteins were variedly affected with a general decline in the initial stages followed by an increase compared to the untreated leaves. Hemicellulose and cellulose was significantly increased in vegetable amaranth and lignin content was significantly increased in African nightshade following UV-C treatment. Chlorophyll and carotenoid contents declined within 2–4d during storage, depending on storage conditions; but thereafter increased again significantly compared to the control. Aerobic mesophyllic and yeast counts were significantly reduced by UV-C treatment, while mould counts were not affected. The findings demonstrate the potential of using hormic UV-C for maintaining the nutritional quality of AIVs during their supply chain as an easy to apply and effective tool, hence contributing to improved food accessibility and food safety in Sub-Saharan areas such as Kenya.

Fermentation of African indigenous leafy vegetables to lower post-harvest losses, maintain quality and increase product safety

To investigate effects of salinity stress on growth, nutrient status, chlorophyll and water consumption, four different saline irrigation waters (S0= 0.3 dS/m-1 control, S1=1.5 dS/m-1, S2=3 dS/m-1, S3=5 dS/m-1) were applied to two-year Chandler saplings which were grafted on Juglans nigra L. (JN), Paradox (PR) and Juglans sieoboldiana L. (JS) walnut rootstocks. Three different salts including NaCl, MgSO4, and CaCl2 were used to prepare saline irrigations. Shoot length change rate (%) was varied between 77.57 (JN) to 81.83 (PR) for S0 salinity treatments and between 55.60 (JS) to 56.84 (PR) for S3 treatments. The plant diameter change rate (%) varied between 75.10 (JN) to 99.22 (PR) for S0 treatments and 60.63 (JN) to 80.97 (PR) for S3 treatments. Average of root length (cm) was between 30.75 cm (JN) to 37.50 cm (PR) for S0 treatments, and 8.91 cm (JN) to 21.50 cm (PR) for S3. Number of roots changed between 19.00 (JS) to 22.16 (PR) for S0 treatments and between 6.41 (JN) and 8.08 (PR) for S3 treatments. Sodium (Na) content (%) in S3 was 1.41, 1.97 and 3.41 in JN, PR, and JS, respectively. Chloride (Cl-) content (ppm) for S3 was 0.88, 0.99 and 0.91 in JN, PR, and JS, respectively. Ca/Na ratios of 0.43, 0.27 and 0.14 and K/Na ratios of 0.24, 0.12 and 0.10 were detected in JN, PR, and JS, respectively. Depending on leaf Na+, Cl- and K contents, K/Na and Ca/Na ratios, the ranking of salinity tolerance of rootstocks were determined as JN˃ PR ˃ JS.

Analysis of the marketing behaviour of African indigenous leafy vegetables among smallholder farmers in Nyamira County, Kenya

The African Indigenous Leafy Vegetables (AILV) agricultural sub-sector in Kenya has in recent times gained considerable prominence and attention. A diverse number of studies have underpinned the role it can play in improving the economic standing of smallholders, while playing an imperative nutritional role in the diets of many consumers. Stemming from increased awareness on the rise of various lifestyle illnesses and crusaders championing for healthy eating habits, the demand of AILV, as healthier dietary alternatives, has been gradually on the rise. However, the socioeconomic and institutional factors that influence market participation and the effect of choice of market packages on AILV income are still not clear. Therefore, the main objectives of the study were: to characterize the socio-economic attributes of AILV farmers; to determine factors influencing households’ market participation behaviour; and to identify the combination of market outlets that deliver the highest payoffs (income) to farmers. The study was based on data collected from a sample of 254 households drawn from Nyamira North Sub-County in Nyamira County. A multistage sampling procedure was used to arrive at the sample, with semi structured questionnaires employed as the research instrument to collect qualitative and quantitative data through face to face interviews. The determinants of market participation behaviour among smallholders was estimated by an ordered probit model, while the combination of market outlets that delivered the highest payoffs (income) to farmers employed a multinomial endogenous switching regression. SPSS and STATA software were used for data analysis and management. Findings revealed that marketing experience, land ownership, households’ food self-sufficiency, contractual marketing, access to credit and extension services significantly influenced the regimes in which smallholders participated in markets. Further, using market packages that contained urban market outlets led to higher incomes among smallholders. It is not enough that farmers merely participated in markets, rather they should participate in markets profitably as net sellers. Identifying the specific challenges and requirements that are unique for each market regime (net sellers, autarkic and net buyers) through proper targeting and screening of farmers is necessary. Here, equipping extension workers with the ability to address the specific needs of each group is recommended. Urban markets, in isolation as well as in market packages, were clearly shown to offer higher incomes in actual and counterfactual scenarios. Improving the condition of roads linking urban markets to producers could potentially reduce transportation costs of accessing such urban markets. This could go on to encourage the use of urban markets among farmers, who stand to gain better income and gradually fish themselves out of poverty traps.

Health Promoting Potentials of Selected South African Indigenous Leafy Vegetables

Health Promoting Potentials of Selected South African Indigenous Leafy Vegetables

Diversity and immune boosting claims of some African indigenous leafy vegetables in Western Kenya

A survey was carried out to document the diversity and immune boosting claims of African indigenous leafy vegetables (AILVs) in Western Kenya. Both qualitative and quantitative methods of data collection were used. The results showed that there is diversity of AILVs in the study area with nine popular and frequently consumed, but cassava leaves, stinging nettle and russian comfry are not popular. Seven of these are cultivated but two, stinging nettle (Urtica massaica) and vine spinach (Basella alba) grow wildly. The AILVs are cultivated at subsistence level on home gardens with minimal inputs and only excess of this is sold. The religion one belonged to was significant (p<0.05) in determining consumption or not of some of the vegetables. The vegetables are rain fed and the process of harvesting is by first uprooting during thinning followed by breaking the main stem and finally plucking off the leaves with maturity. Vegetable preparation in most households was mainly by women. The elderly women were keen in this process and spent more time in preparing the vegetables which were believed to be ‘nutritious’. There was no processing and preservation of the AILVs for use during the dry season. The communities rely on wild weeds during such seasons. The AILVs though consumed for good nutrition are also associated with various medicinal and immune boosting claims. Out of the nine, five are known for various health benefits, African nightshade and spider plant for good nutrition by 31.8% and 25.1% of the respondents, respectively, slender leaf for healing power by 34%, cowpea leaves and slender leaf for anti-aging by 50% and 43.8%, respectively, and cowpea leaves (43.6%) and amaranthus (53%) for smooth skin and adding blood, respectively. Chi square analysis indicated that African night shade, spider plant and amaranthus are statistically significant (p<0.05) in contributing to good nutrition, healthy functioning of the body and immune boosting. Further analysis showed that spider plant and amaranthus are significant (p<0.05) for immune boosting.

English

African indigenous leafy vegetables have the important role of providing essential minerals, vitamins and amino acids in diets of poor smallholder farmer households in sub-Saharan Africa. A study was conducted to quantify the influence of applying cattle and goat manure on the biomass yields and crude protein content of two commonly used African leafy vegetables (Cleome gynandra and Amaranthus hybridus) when subjected to varying leaf cutting management. Treatments for each vegetable consisted of a combination of three manures (control, cattle and goat) and three cutting regimes (cutting edible leaves, all harvestable leaves and cut only at the end) utilised in randomised block design. The results showed significant increase in leaf biomass yields and crude protein content of both vegetables due to manure application. Goat manure was superior to cattle manure due to its higher quality in terms of nutrient content and lower C:N ratio. Cutting the edible leaves more frequently, every fortnight, was associated with the highest leaf biomass yield and crude protein in treatments where manure was applied. It was concluded that potential exist for smallholder farmers to benefit from adopting appropriate manure and leaf cutting regime. A combination of goat manure and frequent cutting of the tender edible leaf tips is recommended. The results point to the potential of maximizing biomass yield and quality of the vegetable leaves by adopting appropriate nutrient supply and leaf cutting regime.   Key words:       Animal kraal manure, nutritional security, smallholder farmers, indigenous vegetables, leaf defoliation.

Folkloric Cues and Taste Bias in African Vegetable Foods

Food is significant beyond its nutritive value and its dietary customs are culturally contextualised. Folklore, the unwritten cultural evidence of a people, presents a stable platform for cultural analysis of oral food cultures. Using a biocultural approach, this study traces folkloristic influences on African indigenous leafy vegetables preference and dietary habits. Folkloristic products with a semiotic dimension are of particular interest. Norms, acts and events that dictate their use are analysed from a sociolinguistic perspective. These studies show that the folklore of the agropastoral Luo abound with useful reference to vegetables; indigenous leafy vegetables are more than just food. Gender, taste, textural preferences, recipe constructs and olfactory attributes of vegetable foods and sectarian taboos are discussed. The argument is that in general vegetable consumption reflects cultural backgrounds and experiences. Sixteen recorded sayings, proverbs, illustrative metaphors, mantras, lexical phrases, tropes and folktales depicting both wrong and right meanings suggest that vegetable foods are a less preferred food. Cultural factors forcefully determine semiotic workings that underlie food consumption and are more imposing largely determining what is palatable and what is not.