Breeding of Vegetable Cowpea for Nutrition and Climate Resilience in Sub-Saharan Africa: Progress, Opportunities, and Challenges

Currently, the world population is increasing, and humanity is facing food and nutritional scarcity. Climate change and variability are a major threat to global food and nutritional security, reducing crop productivity in the tropical and subtropical regions of the globe. Cowpea has the potential to make a significant contribution to global food and nutritional security. In addition, it can be part of a sustainable food system, being a genetic resource for future crop improvement, contributing to resilience and improving agricultural sustainability under climate change conditions. In malnutrition prone regions of sub-Saharan Africa (SSA) countries, cowpea has become a strategic dryland legume crop for addressing food insecurity and malnutrition. Therefore, this review aims to assess the contribution of cowpea to SSA countries as a climate-resilient crop and the existing production challenges and perspectives. Cowpea leaves and immature pods are rich in diverse nutrients, with high levels of protein, vitamins, macro and micronutrients, minerals, fiber, and carbohydrates compared to its grain. In addition, cowpea is truly a multifunctional crop for maintaining good health and for reducing non-communicable human diseases. However, as a leafy vegetable, cowpea has not been researched and promoted sufficiently because it has not been promoted as a food security crop due to its low yield potential, susceptibility to biotic and abiotic stresses, quality assurance issues, policy regulation, and cultural beliefs (it is considered a livestock feed). The development of superior cowpea as a leafy vegetable can be approached in different ways, such as conventional breeding and gene stacking, speed breeding, mutation breeding, space breeding, demand-led breeding, a pan-omics approach, and local government policies. The successful breeding of cowpea genotypes that are high-yielding with a good nutritional value as well as having resistance to biotics and tolerant to abiotic stress could also be used to address food security and malnutrition-related challenges in sub-Saharan Africa.

The Antioxidant Analysis of Selected Types of Climbing Plants with Therapeutic Effect

Climbing plants with therapeutic effects are relatively little studied group of medicinal species. In the collection of climbing species planted in 2019 in the Botanical Garden of the Slovak University of Agriculture (SUA) in Nitra, we observed the growth and potential food, horticulture and healing use. For the antioxidant analysis, 7 species from 152 plants of 13 genera and 22 species were selected. The highest antiradical activity was recorded in the species Vigna sinensis, where reached average measured values achieved up to 73.79%. However, the related species Vigna unguiculata achieved only 26% of antioxidant activity. Of the fruits, the highest activity was Momordica charantia in immature state (73%). Other fruits showed very low antiradical activity

Identification and Quantification of Phenolic Compounds in Grains of Biofortified Cowpea Cultivars, Before and After Cooking

Objective:

This study aimed to identify and quantify phenolic compounds in the grains of biofortified cowpea (Vigna unguiculata) cultivars before and after cooking.

Methods:

We analyzed two cultivars of genetically improved cowpeas, namely BRS Aracê and BRS Tumucumaque. Raw and cooked samples of the cultivars were analyzed (in triplicate). The concentrations of phenolics, flavonoids, anthocyanins, and flavanols, as well as the antioxidant activity, were determined. Phenolic compounds were identified and quantified using high-performance liquid chromatography.

Results:

Grains of cultivar BRS Tumucumaque had higher concentrations of total phenolic compounds before (297.23 ± 4.24 (mean ± standard deviation) mg/100 g) and after (147.15 ± 6.94 mg/100 g) cooking, and higher concentrations of total flavonoids before (49.36 ± 2.02 mg/100 g) and after (23.97± 0.67 mg/100 g) cooking. Anthocyanins were not measured in the grains of either cultivars. There was a statistically significant reduction in the concentration of total flavanols after cooking, with the greater retention in BRS Aracê. Similarly, the antioxidant activity was significantly reduced after cooking, with greater reductions in BRS Tumucumaque than in BRS Aracê. Five phenolic acids were identified and quantified, including gallic, caffeic, and ferulic acids.

Conclusion:

We conclude that cooking affected the concentrations of phenolic compounds in the cultivars, as well as the antioxidant activity exhibited by these cultivars. The cultivars contained beneficial compounds that can contribute to disease prevention and health maintenance.

Plant growth-promoting actinobacteria on chickpea seed mineral density: an upcoming complementary tool for sustainable biofortification strategy

The present study was evaluated to test the potential of plant growth-promoting actinobacteria in increasing seed mineral density of chickpea under field conditions. Among the 19 isolates of actinobacteria tested, significant (p < 0.05) increase of minerals over the uninoculated control treatments was noticed on all the isolates for Fe (10–38 %), 17 for Zn (13–30 %), 16 for Ca (14–26 %), 9 for Cu (11–54 %) and 10 for Mn (18–35 %) and Mg (14–21 %). The increase might be due to the production of siderophore-producing capacity of the tested actinobacteria, which was confirmed in our previous studies by q-RT PCR on siderophore genes expressing up to 1.4- to 25-fold increased relative transcription levels. The chickpea seeds were subjected to processing to increase the mineral availability during consumption. The processed seeds were found to meet the recommended daily intake of FDA by 24–28 % for Fe, 25–28 % for Zn, 28–35 % for Cu, 12–14 % for Ca, 160–167 % for Mn and 34–37 % for Mg. It is suggested that the microbial inoculum can serve as a complementary sustainable tool for the existing biofortification strategies and substantially reduce the chemical fertilizer inputs.

Effect of canning on color, protein and phenolic profile of grains from kidney bean, field pea and chickpea

The aim of the present study was to evaluate the effect of canning on color, protein and phenolic profile of grains of kidney bean, field pea and chickpea varieties/accession. Color of grains of different pulses was enhanced after canning. Grains L* (lightness) decreased while a* (redness to yellowness) and b* (greenness to blueness) increased after canning in all the pulses. Protein profiling of grains of different pulses after canning revealed that kidney bean and chickpea, respectively, had the least and the most thermally susceptible polypeptides. Kidney bean and chickpea showed higher Percentage washed drained weight (PWDW) than field pea. Pulse with more grain hardness and PWDW showed higher degree of grain splitting during canning. Grain splitting was also higher in dark colored accessions/varieties as compared to the light colored. Ferulic acid was the most predominant compound present in raw grains of different pulses. Raw kidney bean grains showed higher accumulation of catechin, chlorogenic, protocatechuic acid, p-coumaric acid and ferulic acid than those of chickpea and field pea. Canning caused reduction in all the phenolic compounds except gallic acid and most prominent effect of canning on protocatechuic acid, chlorogenic and ferulic acid was observed.

Cowpea (Vigna unguiculata L. Walp), a renewed multipurpose crop for a more sustainable agri-food system: nutritional advantages and constraints

The growing awareness of the relevance of food composition for human health has increased the interest of the inclusion of high proportions of fruits and vegetables in diets. To reach the objective of more balanced diets, an increased consumption of legumes, which constitutes a sustainable source of essential nutrients, particularly low-cost protein, is of special relevance. However, the consumption of legumes also entails some constraints that need to be addressed to avoid a deleterious impact on consumers' wellbeing and health. The value of legumes as a source of nutrients depends on a plethora of factors, including genetic characteristics, agro-climatic conditions, and postharvest management that modulate the dietary effect of edible seeds and vegetative material. Thus, more comprehensive information regarding composition, especially their nutritional and anti-nutritional compounds, digestibility, and alternative processing procedures is essential. These were the challenges to write this review, which focusses on the nutritional and anti-nutritional composition of Vigna unguiculata L. Walp, an emerging crop all over the world intended to provide a rational support for the development of valuable foods and feeds of increased commercial value. © 2016 Society of Chemical Industry.

Preparation, nutritional composition, functional properties and antioxidant activities of multigrain composite mixes

Multigrain composite mixes were prepared from different cereals, legumes, millets, nuts along with condiments by different processes. Multigrain composite mixes had 10 to 12% moisture, 56 to 61% carbohydrate, 15 to 20% protein, 9 to 13% crude lipid and 2 to 3% ash. Energy value ranged from ~1600 to 1700 kJ/100 g. Among the vitamins studied, thiamine and riboflavin content varied from 0. 23 to 0.45 mg% and from 8.7 to 21.6 microgram% respectively. Dietary fibre was in the range of 12.4-16.5%. Swelling power of these mixes was about 10; however solubility varied from 17 to 22%. In-vitro Starch digestibility varied from 60 to 76%. Phytic acid content in these multigrain composite mixes varied from 0.6 to 0.8%. Poly-phenols ranged from 1.2 to 1.5%, DPPH free radical scavenging activity ranged from 75.2-86.2% and metal chelating activity ranged from 1.9 to 3.9%. Pasting profile by a Brabender Viscograph of these mixes indicated that they have cross linked starch type behaviour. These multigrain composite mixes can be used for the preparation of food formulations, savory products, pan cake, snacks preparation like muruku and chakli.