Influence of germination on the soluble carbohydrates and dietary fibre fractions in non-conventional legumes

BACKGROUND: Mango is a highly perishable seasonal fruit and large quantities are wasted during the peak season as a result of poor postharvest handling procedures. Processing surplus mango fruits into flour to be used as a functional ingredient appears to be a good preservation method to ensure its extended consumption.

RESULTS: In the present study, the chemical composition, bioactive/antioxidant compounds and functional properties of green and ripe mango (Mangifera indica var. Chokanan) peel and pulp flours were evaluated. Compared to commercial wheat flour, mango flours were significantly low in moisture and protein, but were high in crude fiber, fat and ash content. Mango flour showed a balance between soluble and insoluble dietary fiber proportions, with total dietary fiber content ranging from 3.2 to 5.94 g kg−1. Mango flours exhibited high values for bioactive/antioxidant compounds compared to wheat flour. The water absorption capacity and oil absorption capacity of mango flours ranged from 0.36 to 0.87 g kg−1 and from 0.18 to 0.22 g kg−1, respectively.

CONCLUSION: Results of this study showed mango peel flour to be a rich source of dietary fiber with good antioxidant and functional properties, which could be a useful ingredient for new functional food formulations. Copyright © 2011 Society of Chemical Industry

Evaluation of processed green and ripe mango peel and pulp flours (Mangifera indica var. Chokanan) in terms of chemical composition, antioxidant compounds and functional properties.

The effects of seed treatments, including cooking, popping germination and flour air classification, on the functional properties and antinutritional factors of Amaranthus caudatus and Amaranthus cruentus seeds were studied. Thermal treatments increased the water absorption with a maximum value of 5.1 and 6.3 g g−1 in flour of popped seeds of both species. Generally, fat absorption increased after the treatments. Air classification and germination followed by drying at low temperature increased the foam stability of the flours, while thermal treatment and germination followed by drying at higher temperatures reduced the foam stability. All treatments except air classification decreased the emulsion stability. Also, all treatments except germination followed by drying at 30 °C increased the flour dispersibility, whereas the soluble nitrogen index was increased in the germinated seed flours and decreased in thermal treated seeds and air-classified flours. Air classification increased the contents of phenolic compounds and phytate and decreased the contents of enzyme inhibitors, whereas the thermal treatments reduced the contents of phenolic compounds, phytate and enzyme inhibitors to a greater extent for cooking than for popping. Germination followed by drying reduced the level of phenolic compounds, phytate and enzyme inhibitors. Copyright © 2006 Society of Chemical Industry

Seed treatments affect functional and antinutritional properties of amaranth flours

The research was carried out to evaluate the effect of addition of yellow maize (YM) and orange fleshed sweet potato (OFSP) flours on the quality of wheat bread. Maize and sweet potato were processed into flour and mixed with wheat flour for bread production. Five samples of bread were produced and denoted as Samples A to E. Sample A was the control with 100% wheat flour, while Sample B to E had maize and sweet potato flours added in an increasing order of 5 to 20%. The physical properties of the bread loaves were evaluated and the result decreased significantly with increasing levels of yellow maize and orange fleshed sweet potato flours. The loaf volume varied from 340 to 182 cm3 and the bread specific volume ranged from 1.35 to 0.99 cm3/g. The result of the proximate composition showed that moisture and protein contents decreased significantly (p<0.05) with increase in yellow maize and orange fleshed potato flours varying from 34.97 to 29.97% and 13.12 to 7.67% respectively. The fat, crude fibre, ash and carbohydrate contents of the bread samples generally increased significantly (p<0.05) with increase in maize and orange fleshed potato flours. The result of the mineral content revealed that β-carotene and calcium increased significantly with increased levels of maize and sweet potato. The values of magnesium iron and phosphorus in the bread samples had no definite trend. The result of the sensory properties showed that there was significant difference in the texture and taste of 100% wheat bread and the other samples. The 100% wheat bread recorded the highest scores in all the parameters evaluated however all the other samples were well accepted. There was a decrease in the values of overall acceptability, appearance and flavor of the bread samples with increasing levels of maize and sweet potato flours but the decrease was not significantly different.

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Quality Evaluation of Composite Bread Produced from Wheat, Maize and Orange Fleshed Sweet Potato Flours

The effects of hydration, cooking, autoclaving, germination and their combination on the reduction/elimination of antinutrients and the improvement of in vitro protein digestibility of the tribal pulse, Vigna unguiculata subsp. unguiculata were investigated. Hydration and germination processes were less effective in reducing l -Dopa and trypsin inhibitor activity. Cooking and autoclaving of presoaked seeds drastically reduced the content of total free phenolics, tannins, phytic acid, hydrogen cyanide, trypsin inhibitors and oligosaccharides. Germination (96 h) process reduced the total free phenolics, tannins, hydrogen cyanide and phytic acid. The combination of germination followed by autoclaving completely eliminated the total free phenolics, tannins, hydrogen cyanide, phytic acid, trypsin inhibitor, oligosaccharides and phytoheamagglutinating activity. The combination process (germination 96 h + autoclaving) improved the in vitro protein digestibility. We concluded that, a prolonged period of germination followed by autoclaving completely destroyed some of the antinutritional factors.

Effect of processing on antinutrients and in vitro protein digestibility of the underutilized legume, Vigna unguiculata (L.) Walp subsp. unguiculata

African breadfruit (Treculia africana Decne) seeds were either boiled or roasted and then milled into flour. Chemical composition, functional properties and storage characteristics of raw and treated flours and the effect of partial proteolysis on selected functional properties of the raw flour were determined. Raw flour contained 20.1% crude protein, 2.5% total ash and 13.7% fat. Heat processing significantly (p < 0.05) improved in vitro protein digestibility, and water and fat absorption capacities but decreased bulk density, nitrogen solubility, emulsion and foaming properties, trypsin inhibitor, and phytic acid and polyphenol contents of the samples. Boiling proved more effective than roasting for improving protein digestibility, emulsion capacity and foam stability and reducing antinutritional factor levels. Partial proteolysis increased nitrogen solubility, bulk density and water and fat absorption capacities but decreased foam capacity at hydrolysis levels greater than 35%. Fatty acid and peroxide values of the samples increased during storage. Compared to raw samples, heat processed samples had significantly (p < 0.05) lower and more acceptable peroxide values and free fatty acid contents and higher and more stable water (3.0 g/g sample) and fat (2.4 g/g sample) absorption capacities.

Compositional, functional and storage properties of flours from raw and heat processed African breadfruit (Treculia africana Decne) seeds.

The chemical composition and functional properties of ungerminated and germinated seeds of four advanced lines of cowpeas (IT81D-699, IT82E-18, IT84S-2246-4 and TVx 3236) were investigated. Ungerminated seeds contained 20.1 to 25.8% crude protein, 2.0 to 2.2% lipid, 115.1 to 210.0 mg phytic acid/100 g and 8.9 to 9.6 mg iron/100 g. The polyphenol contents of the brown- and cream-colored beans were similar (192.0 to 196.0 mg/100 g) but were significantly (p < 0.05) higher than the amount (99.8 mg/100 g) found in the white beans. Germination increased the crude protein content, total phosphorus content, nitrogen solubility, fat absorption capacity and foam capacity but decreased ether extract, polyphenol and phytic acid contents, water absorption capacity, bulk density and foam stability of all cowpea lines. Incorporation of up to 0.2 M NaCl improved foam volume. Ungerminated seeds had high water (2.3-3.2 g/g) absorption capacities, while germinated seeds had high fat (3.1-3.6 g/g) absorption capacities. TVx 3236 and IT81D-699 might be selected for combining such characteristics as high crude protein, low phytic acid content and good foaming properties into a single cowpea line through breeding.

Juliet N.T. Emelike

Papers

Compositional, functional and storage properties of flours from raw and heat processed African breadfruit (Treculia africana Decne) seeds.

Evaluation of selected food attributes of four advanced lines of ungerminated and germinated Nigerian cowpea (Vigna unguiculata (L.) Walp.).