Solanum macrocarpon (eggplant) leaf protein isolate (ELI) was hydrolyzed using four different enzymes to produce hydrolysates from alcalase (AH), chymotrypsin (CH) pepsin (PH) and trypsin (TH). CH had an overall stronger antioxidant property and was separated using ultrafiltration membranes into <1, 1–3 and 3–5 kDa peptide fractions. Gel-permeation chromatography confirmed conversion of the ELI (average of 22 kDa) into protein hydrolysates that contained smaller peptides (<6 kDa). A total of 23 peptides consisting of tri and tetrapeptides were identified from the CH, which is a wider spectrum when compared to seven for AH and four each for TH and PH. CH exhibited stronger scavenging activities against DPPH and hydroxyl radicals. CH and TH exhibited the strongest inhibitions against angiotensin-converting enzyme. In contrast, AH was the strongest inhibitor of α-amylase while AH and PH had strong inhibitory activities against α-glucosidase when compared with other hydrolysates. Ultrafiltration fractionation produced peptides that were stronger (p < 0.05) scavengers of DPPH, and hydroxyl radicals, in addition to better metal-chelating and enzyme inhibition agents. The study concluded that the eggplant protein hydrolysates and the UF fractions may find applications in tackling oxidative stress-related diseases and conditions involving excessive activities of the metabolic enzymes.

Hydrolysates were produced using Alcalase (AH), chymotrypsin (CH), pepsin (PH), and trypsin (TH), and also fluted pumpkin leaf protein isolate (FLI) as a substrate. AH had the lowest degree of hydrolysis (16.37%) but exhibited overall superior antioxidant and enzyme inhibitory properties....

Fertility management techniques being promoted in sub-Saharan Africa (SSA) seek to grow indigenous vegetables economically and sustainably. This study was conducted in a phytotron chamber and compared yield, soil carbon (C) speciation and greenhouse gas (nitrous oxide (N₂O) and carbon dioxide (CO₂)) emissions from SSA soils of two ecoregions; the dry savanna (lna, Republic of Benin) and rainforest (Ife, Nigeria) cultivated with local amaranth (Amaranthus cruentus) under manure (5 t/ha) and/or urea (80 kg N/ha) fertilization. Vegetable yield ranged from 4331 kg/ha to 7900 kg/ha in the rainforest, RF, soils and 3165 kg/ha to 4821 kg/ha in the dry savanna, DS, soils. Yield in the urea treatment was slightly higher compared to the manure, and manure+urea treatment, but the difference was not statistically significant. Cumulative CO₂ emissions over 21 days ranged from 497.06 to 579.47 g CO₂-C/kg soil/day in the RF, and 322.96 to 624.97 g CO₂-C/kg soil/day in the DS, while cumulative N₂O emissions ranged from 60.53 to 220.86 mg N₂O-N/kg soil/day in the RF, and 24.78 to 99.08 mg N₂O-N/kg soil/day in the DS. In the RF samples, when compared to the use of urea alone, the combined use of manure and urea reduced N₂O emissions but led to an increase in the DS samples. ATR-FTIR analysis showed that the combined use of manure and manure+urea increased the rate of microbial decomposition in the soils of the DS, but no such effect was observed in soils of the RF. We conclude that combining manure and urea fertilization has different effects on soils of the two ecoregions, and that RF farmers can reduce agricultural N₂O emissions without compromising soil productivity and yield potential.

We quantified the impact of new production technologies on total land area allocated to production of six (ugu, igbagba, tete atetedaye, woorowo, ogunmo and odu) selected high-premium under-utilised indigenous vegetables (UIVs) in south-western Nigeria. Leaf yields and accruable returns were estimated by comparing the data for these parameters at the commencement of the project in 2011 (through a baseline survey) with the same set of parameters after three years (in 2013) of project implementation. Through a structured interview and focus group discussion involving 134 randomly selected respondents (59 women and 75 men) from the 350 UIVs cooperative members in the rainforest and derived savanna agroecologies in four states (Oyo, Ondo, Osun and Ekiti) of south-western Nigeria, we studied the gender gap between male and female farmers with respect to access to productive farm resources. The data obtained were analysed using appropriate descriptive and inferential statistics. On average across south-western Nigeria in 2013, areas of 7.67, 7.0, 5.6, 1.9, 2.83 and 0.72 ha were planted to ugu, igbagba, tete atetedaye, woorowo, ogunmo and odu, respectively, compared to areas in 2011 of 0.3, 0.2, 0.6, 0, 0.32 and 0 ha, respectively. Yield analyses showed that the productivity of ugu, igbagba, tete atetedaye, woorowo, ogunmo and odu increased by 62%, 67%, 60%, 100%, 64% and 100%, respectively, as a result of the seeding rate technology applied between 2011 and 2013. More than 80% of the male and female respondents were aged between 31 and 60 years and possessed mean UIV farming experience of 18.7 years (males) and 13.4 years (females). The average farm area was 3.4 ha for men and 2.8 ha for women. The difficulty in accessing agrochemicals, modern technologies and marketing outlets was skewed towards females. We identified inadequate finance, lack of storage facilities, marketing outlets, multiple household responsibilities, lack of technology, lack of inputs and gender inequality as some of the problems associated with UIV production as perceived by both male and female respondents. Age (r = 0.290) and farming experience (r = 0.216) of female UIVs farmers, and age (r = 0.300), farming experience (r = 0.226), education (r = 0.363) and income (r = 0.224) of male UIV farmers were positively correlated with access to production resources (p≤0.01). In conclusion, there is a need to drop policies that are less favourable to rural women and to focus on the appreciation of their role as producers of wealth, and additionally to strengthen the network of public services in rural areas, including education and welfare services.

A large population in Africa, particularly West Africa, depends on leafy vegetables such as red amaranth (Amaranthus cruentus), Lagos spinach (Celosia argentea), and African eggplant (Solanum macrocarpon) as affordable and readily available sources of nutrition. These vegetables are rich sources of phenolics, minerals, vitamins, and bioactive compounds, contributing significantly to dietary nutrition and providing an important source of revenue for farmers. However, the temperature rise due to climate change threatens their availability and nutritional value. This study assessed the effects of temperature regimes (23, 30, and 40 °C) on the growth and quality of these vegetables under greenhouse conditions for 48 (A. cruentus and C. argentea) and 54 (S. macrocarpon) days after sowing by measuring biomass (leaf, stem, shoot, root dry weight, root/shoot and leaf area), photosynthetic parameters, pigments, sugars, mineral content, antioxidant activity, total phenolic compounds, total flavonoids, and free amino acids. Temperature significantly affected biomass, with A. cruentus and C. argentea showing declines of 13.5–32.2% and 5.1–27.8%, respectively, at 40 °C compared to 23 °C, indicating sensitivity to heat stress. Photosynthetic rates increased with a rise from 23 to 30 °C by 2.1–29.2% across all species. Sugar contents remained generally stable, except for notable decreases in glucose and soluble sugars by 43.3% and 40.5%, respectively, in C. argentea between 30 and 40 °C, and a 52.6% reduction in starch in S. macrocarpon from 23 to 40 °C. Mineral nutrient responses varied by species; however, they exhibited similar increases in nitrogen and phosphorus, as well as decreases in calcium and manganese, at higher temperatures. Notably, antioxidant capacity and total phenolic compounds declined significantly in C. argentea (8.1% and 8.0%) and S. macrocarpon (4.7% and 13.3%). In contrast, free amino acid contents increased by 35.2% and 28.8% in A. cruentus and S. macrocarpon, respectively. It was concluded that A. cruentus and C. argentea suffer reduced growth and nutrients at 40 °C, while S. macrocarpon maintains biomass but has some biochemical declines; antioxidant capacity and phenolics drop at high temperatures, free amino acids rise, and 30 °C is optimal for all three.