Potential Role of African Fermented Indigenous Vegetables in Maternal and Child Nutrition in Sub-Saharan Africa

Hunger and malnutrition continue to affect Africa especially the vulnerable children and women in reproductive age. However, Africa has indigenous foods and associated traditional technologies that can contribute to alleviation of hunger, malnutrition, and communicable and noncommunicable diseases. The importance of African indigenous vegetables is undeniable, only that they are season-linked and considered as “food for poor” despite their high nutritional contents. The utilization of African indigenous vegetables (AIVs) is hindered by postharvest losses and antinutrients affecting the bioavailability of nutrients. In Africa, fermentation is among the oldest food processing technologies with long history of safe use. Apart from extending shelf life and improving food organoleptic properties, fermentation of African indigenous vegetables (AIVs) is known to improve food nutritional values such as proteins, minerals, vitamins, and other beneficial phytochemicals. It can also increase bioavailability of various vitamins, minerals, and phytochemicals and increase synthesis of vital blood pressure regulators thus protecting against cardiovascular diseases and cancer and further helping fight certain malnutrition deficiencies. Some lactic acid bacteria (LAB) involved in food fermentation are known to produce exopolysaccharides with cholesterol-lowering, immunomodulator, antioxidant, and anticancer properties. Fermented foods (vegetables) are superior in quality and safety since most microorganisms involved in fermentation are good starter cultures that can inhibit the growth of foodborne pathogens and detoxify harmful compounds in foods. Thus, fermented foods can boost growth and well-being in children and women due to their higher nutritional contents. Therefore, fermentation of AIVs can contribute to the attainment of food and nutrition security especially among women and children who rely on these vegetables as a staple source of micronutrients and income. These benefits have a positive impact on the implementation of the second sustainable development goals and African Union agenda 2063. This review is aimed at shedding light on the potential of African fermented indigenous vegetables in combating maternal and child malnutrition in Sub-Sahara Africa.

Impact of COVID-19 pandemic on African indigenous vegetables value chain in Kenya

Background African indigenous vegetables are important for food security and nutrition, and income of the poor farm households. In the era of COVID-19, they are critical for boosting people’s immunity. Unfortunately, both production of and trade in these vegetables is likely to be severely affected by the pandemic. Methods This study examined potential effects of COVID-19 pandemic on production and trade of African indigenous vegetables using a cross-sectional survey of 244 farmers and 246 traders from different regions in Kenya. Results COVID-19 has a negative impact on production and trading of AIVs in Kenya. Findings indicate that 75% of the farmers are experiencing declining production due to reduced access to input, farm labour and output market. Secondly, about 98% of the traders have recorded a drop in sales volumes due to containment measures implemented by the government and personal safety precautions. In particular, farmers’ production and traders’ sales volumes declined by 39 and 65%, respectively, during the first phase of the pandemic. Conclusion The findings indicate that the sub-sector requires targeted interventions which may include input support, careful reopening and control of the open-air markets, reduced taxation and facilitated access to urban markets.

In Vitro Bioaccessibility of the Vitamin B Series from Thermally Processed Leafy African Indigenous Vegetables

Thermal processing of leafy African indigenous vegetables (LAIVs), which are rich in nutrients, especially vitamin B series affects the levels and bioaccessibility of the vitamins. This study investigated the bioaccessibility of vitamin B series in fresh and thermally processed LAIVs. Five commonly consumed indigenous vegetables, Cleome gynadra, Vigna unguilata, Amaranthus viridis, Basella alba, and Cucurbita maxima, were processed by boiling and/or frying, treated to in vitro gastrointestinal digestion procedure, and levels of vitamin B series determined before and after treatment. The vitamin B series in fresh LAIVs ranged from 0.73 ± 0.01 mg/100 g (B9; spider plant) to 174.16 ± 3.50 mg/100 g (B2; vine spinach) and had both significant increase (ranging from +8.71% to +446.84%) and decrease (ranging from −0.44% to −100.00%) with thermal processing ( p < 0.001 ). The in vitro digestion resulted in a significant increase ( p < 0.001 ) of vitamins ranging from 5.18% (B5; boiled cowpeas) to 100% (B2, B3, and B6 in several processed vegetables). Where detected, the bioaccessible levels of vitamin B series in fresh, processed, and in vitro digested samples were sufficient to meet the Recommended Dietary Allowances (RDA) of children and adults. These findings support the promotion of a nutritional approach to malnutrition resulting from vitamin B series deficiency.

Rediscovering pride in agricultural heritage through cultivation of African Indigenous vegetables (AIVs) as climate acquiescent vegetables, immune and health in response to COVID-19 pandemic in Zimbabwe

African Indigenous Vegetables are assert to cope with climate variability beside their great potential as both food and medicine in Zimbabwe. They can be easily grown in drought prone areas with low rainfall as they are resistant to adverse environmental factors. Inimitable opportunities are offered through cultivation of AIVs to diversify farming systems so as to ensure food security and are cheap alternatives as compared to their expensive exotic counterparts. Alternative approaches to reduce escalating numbers of current Covid-19 patients and death is to introduce nutrient intervention through rediscovering of pride in agriculture through cultivation and commercialisation of AIVs in Zimbabwe. AIVs have great potential to improve immune response by supplementing dietary requirements (micronutrients) of an individual and can have a positive impact on COVID-19 outcome as they play a significant role in the immune system. AIVs have antifungal, acaricidal, antiviral, anticancer and act as immune stimulants. There is need for persuasive research based information, suitable national legislation and information campaigns on cultivation and consumption of AIVs in Zimbabwe.

Effect of cooking methods on levels of folates and ascorbic acid in cowpea (Vigna unguiculata L. Walp) from Nairobi, Kenya

Folate (vitamin B9,5-methyltetrahydrofolate) and ascorbic acid (AA) (vitamin C) play a key role in human health and wellbeing. It is greatly established that AA is beneficial in preventing scurvy while folate helps in prevention of neural tube defects and congenital malformations. The main sources of these vitamins are fruits and vegetables especially green leafy vegetables including the African Indigenous Vegetables (AIVs). However, these vegetables are consumed after cooking which leads to loss of the vitamins through oxidation, thermal degradation, and leaching. The study aimed at determining the effect of different cooking methods on the retention of AA and folate in cowpea (Vigna unguiculata L. Walp) as affected by different cooking methods. Folate and AA were determined using high pressure liquid chromatography with ultra UV-visible detection, HPLC-UV after extraction of the vitamins from raw and cooked samples. Analysis of Variance (ANOVA) was used to determine difference in nutrients retention by various cooking methods. Significance was imputed at p<0.05. Raw V. unguiculata ontained 45.516±0.649 mg/100g AA and 91.736±0.586 μg/100g folate. The cooked samples of the vegetable contained folate ranging from 40.713±0.081 to 65.128±0.007 μg/100g and AA ranging from 0.719±0.063 to 24.181±0.051 mg/100g of the edible portion of the vegetable. Cooking the vegetable significantly reduced both folate and AA concentration compared to the raw vegetable samples, p<0.05. Frying raw vegetables with onions and tomatoes was found to retain significant folate and AA than boiling the vegetables, p<0.05. Addition of milk resulted in significant retention of folate and significant loss of AA than boiling, p<0.05. Both lye and sodium bicarbonate significantly reduced folate and AA concentration than boiling, with lye causing significant reduction of both vitamins than sodium bicarbonate p<0.05. It is concluded that cooking reduces folate and AA concentration in cowpea (V. unguiculata L. Walp). Additive such as lye and bicarbonate also reduce the concentration of the vitamins. Cooking cowpea leaves with addition of milk and frying with onion and tomatoes retains more folate than boiling. However, AA is significantly lost in the process than when the vegetable is just boiled.

Smallholder Farmers’ Practices and African Indigenous Vegetables Affect Soil Microbial Biodiversity and Enzyme Activities in Lake Naivasha Basin, Kenya

Loss of soil biodiversity and fertility in Sub-Saharan Africa (SSA) may put the food security of smallholder farmers in peril. Food systems in SSA are seeing the rise of African indigenous vegetables (AIVs) that are underexploited but locally consumed without being considered a primary source of food and income. Here we present a field study, a first of its kind, in which we investigated the effects of different cropping systems and inclusion of AIVs in the farming approach on bacterial and fungal biodiversity and community structures, enzymatic activity, and the alteration status of soils of the smallholder farmers in Kenya. When compared to mainstream farming approaches, the composition and biodiversity of bacteria and fungi under AIV cultivations was significantly different. Tillage had a significant impact only on the fungal communities. Fertilization and soil amendments caused shifts in microbial communities towards specialized degraders and revealed the introduction of specific microorganisms from amendments. Traditional homemade plant protection products did not cause any disturbance to either of soil bacteria or fungi. The soil alteration index based on enzyme activity successfully differentiated the alteration status for the first time in SSA. These findings could be useful for farmers to integrate AIVs with correct sustainable practices for a sustainable future.