Effects of Shade on Microclimate, Canopy Characteristics and Light Integrals in Dry Season Field-Grown Cocoa (Theobroma cacao L.) Seedlings

Effect of shade regimes on gradients of microclimate, canopy extent (leaf area index: LAI) and light integrals in dry season field-grown cocoa (cacao) seedlings was investigated in a rainforest zone of Nigeria. The shade regimes tested were: unshaded/open-to-sun, dense shade and moderate shade. Shade intensity affected solar radiation transmission through cacao canopy, photosynthetic active radiation (PAR) and canopy light attenuation (extinction coefficient, k). Intensity of transmitted radiation below the canopy from incident radiation was highest for open-to-sun, followed by moderate and dense shade, respectively. The temporal trend of intercepted radiation showed that intercepted radiation increased from December to May, and, the values were highest for open-to-sun, followed by moderate and dense shade. The ratio of transmitted (Io) to incident (I) radiation (IO/I) was higher for open sun. Significant differences were found between open-to-sun (unshaded) and moderate and dense shade intensity for value of canopy extinction coefficient (k). The association of growing degree days (GDD), and, total leaf number (TLN) and leaf area index (LAI), were characterized by high coefficient of determination (R2) for the respective open, dense and moderate shade treatments. Inverse of the slope of the regression of relationship between estimated thermal time (°Cdays) and corresponding total leaf number (TLN) denotes leaf appearance rate (phyllochron, in °Cdays/leaf). Rate of leaf appearance was faster in open sun compared with to that in moderate or dense shade intensity. Characteristics of the cacao canopy development were measured by leaf area index (LAI), a parameter which affects the intercepted photosynthetic active radiation (PAR). Higher LAI was obtained in no shade (open sun) compared to that in moderate or dense shade treatments. Unshaded plants had a higher radiation use efficiency (RUE) and RUE values were significantly higher compared to the other two treatments. Low light intensity and LAI for under-storey cacao had negative implications for growth and biomass development. Air temperatures within the cacao field were highest for open sun cacao, followed by moderate and dense shade, respectively; the values increased from December to April, with peak values seen in April

Chemical Composition and Quality Characteristics of Wheat Bread Supplemented with Leafy Vegetable Powders

The study investigated the effect of supplementation of the leaf powders of Telfairia occidentalis, Amaranthus viridis, and Solanum macrocarpon on the chemical composition and the quality characteristics of wheat bread. The bread samples were supplemented with each of the vegetable leaf powders at 1%, 2%, and 3% during preparation. The bread samples were assayed for proximate composition, mineral composition, physical, sensory, and antioxidant properties using standard methods. The addition of vegetable powders significantly increased the protein (9.50 to 13.93%), fibre (1.81 to 4.00%), ash (1.05 to 2.38%), and fat (1.27 to 2.00%). Supplementation with vegetable powder however significantly decreased (p<0.05) the carbohydrate and moisture contents. Significant (p<0.05) increases were recorded for all evaluated minerals as the level of vegetable powder increased. Supplementation with vegetable powder caused significant decrease in total phenolic content, percentage DPPH inhibition, metal chelating ability, ferric reducing antioxidant power, and total antioxidant capacity. Sensory results showed that there was significant decrease in sensory qualities with increasing supplementation. This therefore suggests that bread supplemented with vegetable powder could have more market penetration if awareness is highly created

Potential of Indigenous Vegetable-Fortified Food Products for Improved Human Nutrition and Health in West Africa

The study developed and tested the acceptability of key innovative value-added products, including vegetable-fortified bread and pastry products (cookies and chinchin), using each of these three indigenous vegetables, namely Telfairia occidentalis Hook. F. (fluted pumpkin), Amaranthus virdis L. (local amaranth), and Solanum macrocarpon L. (eggplant). The bread was fortified with each of the individual dried leafy vegetables at levels of 1%, 3%, and 5%. Ogi was also fortified with the equivalent of the dried Telfaria occidentalis in the wet form at 1%, 3%, and 5%, while pastry was fortified with the only extract obtained from amaranth leafy vegetable at 1%, 3%, and 5%. Results from the MicroVeg project showed that bread fortified with 3% (w/w) dried vegetable leaf powders had higher nutritional properties. Pastry formulations that included 3% dried vegetable leaf powders had slightly lower consumer acceptability in terms of taste and color; however, due to the associated potential health benefits, consumers were willing to buy the vegetable-fortified products as replacements for the regular products. This chapter discusses the full details of the nutrition and value addition aspects of MicroVeg with empirical examples of the interventions and the potential contributions to dietary diversity and enhanced family nutrition

Drying characteristics, nutritional and anti-nutritional properties of locust bean seed

AbstractThe need to ensure availability of locust beans when off-season forms the basis of this study. The study investigated the drying characteristics, nutritional composition and some anti-nutritional contents of dried locust beans. Fermented locust beans were dried at 50°C, 60°C, 70°C and 90°C. The moisture contents of the fermented locust seeds were determined at different time intervals between 0 and 480 min. Lower moisture content was achieved in a shorter drying time at higher temperature. The dried locust bean samples had lower moisture contents (12.36–12.76%) compared to control sample (38.76%). Higher drying temperature resulted in low ash content of the samples but increased the fibre, fat and protein content of the samples. The dried samples had low mineral contents compared to the fresh sample, which was used as control. The most abundant mineral in the samples were found to be calcium and zinc. No significant difference was observed in the titratable acidity and the pH of the locust bean samples at varying drying temperature. Increase in temperature resulted to a reduction in the antioxidant, phenolic composition and the anti-nutritional properties of the dried locust bean samples. Panelists preferred samples dried at lower temperature (50°C and 60°C compared with the samples dried at high temperature. The study concluded that locust bean should be dried using a carefully selected temperature to avoid negative impacts on the nutrients of the beans

Extraction Optimization and Antioxidant Properties of African Eggplant (Solanum macrocarpon) Leaf Polyphenols

Optimization of the yield, total phenolic content (TPC), and total antioxidant activities (TAA) of polyphenol concentrates extracted from Solanum macrocarpon leaves was studied using response surface methodology. The process variables investigated included extraction temperature (30, 50, and 70°C), extraction time (2, 4, and 6 h), and dried leaf powder : water ratio (1 : 10, 1 : 20, and 1 : 30 w/v). Box–Behnken design resulted in 15 experimental runs. The results showed the following optimum extraction conditions: temperature, 49.05°C; extraction time, 243 min; leaf powder : water ratio, 1 : 22 w/v. The optimized extraction conditions gave polyphenol concentrate yield, TPC, and TAA values of 24.94%, 421.09 mg GAE/g, and 23.81 mg AAE/g, respectively. Results of the in vitro antioxidant activities of the polyphenol concentrate showed 2, 2-diphenyl-2-picrylhydrazyl hydrate, metal chelating ability, and ferric reducing ability values of 76.78%, 80.22%, and 56.46 mg AAE/g, respectively. The study concludes that the experimental values compared closely with the predicted values, which indicates suitability of the model employed for polyphenol extraction optimization from dried S. macrocarpon leaves

In Vitro Characterization of Fluted Pumpkin Leaf Protein Hydrolysates and Ultrafiltration of Peptide Fractions: Antioxidant and Enzyme-Inhibitory Properties

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. Therefore, it was fractionated by membrane ultrafiltration to give 10 kDa peptide fractions. Gel permeation chromatography showed that the molecular weight of the FLI was 19.77 kDa and that of the hydrolysates was below 7.5 kDa. The hydrolysate peptides had a high content of hydrophobic amino acids but low levels of sulfur-containing amino acids, when compared to protein of FLI. Peptide sequence analysis showed that the hydrolysates consisted of dipeptides, tripeptides, and tetrapeptides with molecular weights below 500 Da. The hydrolysates were also stronger inhibitors of linoleic acid oxidation, α-amylase, α-glucosidase, and angiotensin converting enzyme (ACE) than FLI. Among the fractions, the <1 and 1-3 kDa were the most effective free radical scavengers and metal chelators in addition to their strong inhibitory activities against α-amylase, α-glucosidase, and ACE. We conclude that the AH and low molecular weight peptide fraction (<3 kDa) could find applications in formulating foods with various bioactive properties