In this study, banana and prickly peel flours were oven dried at 60 °C overnight and incorporated at a maximum of 4% (w/w) levels in wheat flour for biscuit production. Wheat, banana, prickly pear and composite flours and biscuits were evaluated for functional, bioactive compounds and antioxidant activities as well as physical properties. Functional properties analysis indicated that banana peel flour (BPF) and prickly pear flours (PPF) showed higher water holding capacity and oil holding capacity, ranging from 2.63 to 4.29 g/ml and from 1.15 to 2.0 g/ml, respectively. Total phenolic content ranged from 10.87 to 17.35 mg/g and from 11.21 to 11,44 mg/g in composite flour blends and total phenolic contents in biscuits improved from 11.365 mg/g to 11.81 mg/g with 4% BPF incorporation; and decrease to 10.92 mg/g with 4% PPF incorporation and 10.79 mg/g with 4% BPF and PPF, respectively. Total flavonoid content ranged from 15.78 to 23.19 mg/g in PPF and BPF, respectively and from 0.75 to 13.31 mg/g for control and composite flours. Moreover, results for Total flavonoid content of biscuits ranged from 17.0 to 33.74 mg/g. DPPH values ranged from 3.29 to 30.0% in flours and 8.12-9.69% in biscuits. FRAP values ranged from 0.57 to 1.51 mg/g for flours and 0.59-0.71 mg/g for biscuits. With regards to colour, incorporation of BPF and PPF resulted in decrease of L* value and b* values for composite flours and decreases in parameter L* and b* values for formulated biscuits. Spread ratio of biscuits showed an increase with addition of BPF and PPF, while diameter and height of biscuits decreased. Hardness of the biscuits increased with addition of BPF and PPF. Results suggest that by incorporating BPF and PPF, it is possible to enhance functional properties, colour parameters, antioxidant activity of the flours and biscuits.

Sweet potato (Ipomoea batatas Lam) is a nutritious crop abundant in calories and bioactive compounds such as beta-carotene, ascorbic acid, polyphenols, and dietary fibre. This study investigated the effect of pretreatments on the physicochemical and functional properties of Ndou sweet potato (NSP) flour. Flour samples were prepared by randomly assigning NSP slices to two treatments (citric acid and sodium metabisulphite) at 5, 10, and 15 g/L concentration for 10 min. Distilled water was used as control. The moisture content (7.70%) of NSP flour treated with citric acid was significantly (p<0.05) higher than that of the flour treated with sodium metabisulphite (5.54%) as the concentration level increased. The treatments did not significantly (p<0.05) affect the protein and fat contents of the NSP flour and protein increased from 2.54 to 2.82%, while fat decreased from 0.69 to 0.61%. Sodium metabisulphite treated samples had a higher L∗ value, ash, and pH level than citric acid treated samples. However, pH was slightly decreased by both treatments from 6.05 to 5.09. Citric acid treated samples had higher a∗ and b∗ values than sodium metabisulphite treated samples. In terms of the functional properties of NSP flour, the treatments significantly (p<0.05) affected the water absorption capacity, viscosity, swelling power, solubility index, and thermal properties although the bulk density and least gelation concentration were not significantly (p>0.05) affected. Sodium metabisulphite was very effective in improving physicochemical and functional properties of NSP flour as compared to citric acid. The findings of this study show the possibilities of using NSP flour in food systems as gelling agent, fat replacer, and thickeners.

Indigenous leafy vegetables (ILVs) play a pivotal role in sustaining the lives of many people of low socio-economic status who reside in rural areas of most developing countries. Such ILVs contribute to food security since they withstand harsher weather and soil conditions than their commercial counterparts and supply important nutrients such as dietary fibre, vitamins and minerals. Furthermore, ILVs contain bioactive components such as phenolic compounds, flavonoids, dietary fibre, carotene content and vitamin C that confer health benefits on consumers. Several studies have demonstrated that regular and adequate consumption of vegetables reduces risks of chronic conditions such as diabetes, cancer, metabolic disorders such as obesity in children and adults, as well as cardiovascular disease. However, consumption of ILVs is very low globally as they are associated with unbalanced and poor diets, with being food for the poor and with possibly containing toxic heavy metals. Therefore, this paper reviews the role of ILVs as food security crops, the biodiversity of ILVs, the effects of processing on the bioactivity of ILVs, consumer acceptability of food derived from ILVs, potential toxicity of some ILVs and the potential role ILVs play in the future of eating.

Bambara groundnut (Vigna subterranean) is an African legume that belongs to the family and subfamily of Fabaceae and Faboidea, respectively. It is becoming one of the most utilized legumes after being underutilized for many years in Africa. It is the third most significant legume after groundnut (Arachis hypogaea) and cowpea (Vigna hypogea). Bambara groundnut (BGN) is a complete food because of its richness in nutritional properties such as crude fiber, iron, protein, carbohydrate, fat and minerals. Moreover, BGN possesses antioxidants properties as it contains phytochemicals, such as tannins, flavonoids and phytic acids which possess health benefits for humans such as preventing diabetes, stroke, atherosclerosis, heart disease, cancer, Alzheimer and cardiovascular diseases. In addition, these phytochemicals extend the shelf life of food products and have antimicrobial properties which can inhibit microbial growth. This paper highlights the current findings on BGN nutritional composition, health benefits, antimicrobial and antioxidant properties. Therefore, it is advisable for food industry to exploit BGN grain to its full potential to tackle challenges of food security and nutrition globally.

Marula (Sclerocarya birrea, A. Rich) is an underutilized wild edible fruit tree species that grows naturally across large parts of sub-Saharan Africa. Almost every part of the tree, from leaves, bark, wood, roots and fruit has some use. The fruit is consumed fresh or processed. The fruit contains considerable amounts of dietary fiber, protein, vitamins (A, B₃, C, E and carotene), minerals, amino acids, and fatty acids. The main structural classes of the marula fruit include polyphenols, flavonoids, condensed tannins and polysaccharides (pectin), these components can prevent chronic and degenerative diseases. The marula fruit is functional food because of its components that have beneficial properties on health and prevention of diseases. Different studies have demonstrated the utilization of the marula fruit in juice processing, alcohol based products, jams and jellies, fruit leather, vinegar and animal feed. Therefore, this article reviews the nutritional composition, polyphenolic compounds and biological activities of the marula fruit and its reported use in food applications.

The flours of finger millet (Eleusine coracana) from light brown and dark brown varieties fermented spontaneously for 96 h were evaluated for their bioactive compounds, antioxidant activity and physicochemical properties. The consumer acceptability of the fermented porridges was also determined. Bioactive compounds of finger millet (FM) flours significantly (p < .05) increased with fermentation time, total polyphenolic content increased from 166 to 488 mg/100 g (light brown) and 420 to 606 mg/100 g (dark brown) and total flavonoid content increased from 160 to 330 mg/100 g (light brown) and 249 to 465 mg/g (dark brown). However, the total anthocyanin content of FM flours decreased with fermentation time. The DPPH activity of FM flours significantly (p < .05) increased with fermentation time from 52 to 58% (light brown), 53 to 59% (dark brown) and inhibitory effect on lipid peroxides significantly (p < .05) increased from 0.9 to 1.3% (dark brown) and 1.7 to 4.5% (dark brown). Fermentation significantly increased the crude protein of FM flours (light brown, 7.12 to 9.43%) and (7.80 to 9.53%, dark brown). Dietary fiber, fats, moisture and carbohydrates significantly (p < .05) decreased. Total titratable acid significantly (p < .05) increased from 0.49 to 1.77 g/100 g (light brown) and 0.47 to 1.58 g/100 g (dark brown). Fermentation resulted in the decrease of FM flours pH values. However, the total soluble solids were significantly (p < .05) different in both flours. Fermentation caused the lightness (L*) and redness (a*) to decrease and the yellowness (b*) of both flours to increase with time. The textural properties of the FM porridges decreased with fermentation time. The FM flours of both varieties which were fermented for 24 h resulted in porridges with the best sensory attributes. The results suggest that spontaneous fermentation could be an effective way of improving the bioactive compounds and antioxidant activity of FM flours.