Proximate composition and selected functional properties of African Breadfruit and sweet potato flour blends

Full-fat African breadfruit flour was used to replace 30, 40, 50, 60 and 70% of sweet potato flour. The chemical composition and functional properties of composite flours showed that they contains more protein, fat, and ash and less carbohydrate than sweet potato flour. With increasing level of supplementation of breadfruit, ash, protein and fat contents increased while carbohydrate decreased. The composite flours possessed higher water absorption than sweet potato flour. The water absorption capacity increased from 20% for sweet potato flour to the range of 85–120% for composite flours. The oil absorption capacities for some composite flours were higher than that for sweet potato but less than that of breadfruit. Composite flours had good foaming capacity but lacked foaming stability. The bulk density of the composite flours was found to be low which will be an advantage in the preparation of weaning food formulations.     

Chemical composition and selected functional properties of sweet orange (Citrus sinensis) seed flour

Flour samples were prepared from dehulled and undehulledsweet orange (Citrus sinensis) seeds. The flour samples were evaluated for proximate composition, mineralcontent and selected functional properties. Proximate analysis showed a composition of 54.2% fat, 28.5% carbohydrate, 5.5% crude fiber, 3.1% crude protein and 2.5% ash for the dehulled orange seed flour (dry weight).Mineral analyses showed high levels of calcium and potassium in flour samples. Partially defatted and undefatted flour samples prepared from dehulled orangeseeds had least gelation concentrations of 10 and 12%(w/v), respectively. Water absorption capacity for thedefatted and undefatted dehulled flour samples were 240and 220%, respectively. Defatting improved oil absorptioncapacity of the orange seed flour by 84%. Emulsion activity, emulsion stability and foaming capacity decreasedfollowing defatting of flour. Foam prepared from defattedflour was less stable than that from full-fat flour.Incorporation of NaCl up to 0.2 M improved the foamingcapacity of orange seed flour.     

Proximate composition and selected functional properties of Detarium microcarpum

The proximate composition and functional properties of Detariummicrocarpum seed flour were evaluated. The dehulled seed flour contained3.5% moisture, 3.5% ash, 2.9% crude fiber, 15% crude fat, 37.1% crude protein and 39%carbohydrate. Functional properties showed bulk densityof 0.86 g/cm³ for dehulled and 0.92 g/cm³ for undehulled flour.Water absorption capacity was 4.9 g/g for dehulled and 5.1 g/g forundehulled seed flour; oil absorption capacity was 0.75 g/g for dehulled.The emulsion activity was 4.4% and 4.3% for dehulled and undehulled,respectively. The results obtained above showed that the Detariummicrocarpum seed flours have good nutritional quality and the functionalproperties confirmed their suitability for use in various food preparations.As a result, its present limited use should be expanded into additionalopportunities.     

Effect of heat treatment on the proximate composition,energy values,and levels of some toxicants in African yam bean (Sphenostylis stenocarpa) seed varieties

The effects of heat treatments on the proximate composition, energy content, and levels of some antinutritional factors in brown and marble-colored African yam bean (AYB) seed flours were investigated. In raw brown and marble-colored AYB seed flours; moisture content, dry matter, crude protein, crude fat, ash, total carbohydrate and caloric value did not differ significantly at the 5% level. Autoclaving and cooking slightly increased the moisture level. Crude protein, crude fat, and ash contents were decreased by autoclaving and were further decreased by cooking. The decrease was not, however, considerable for the AYB that is not eaten raw and whose full nutritional potential as a legume can be derived only when heat treated, as previous reports have indicated for legume seeds.The levels of the toxicants were generally higher in the raw brown AYB compared to the marble-colored, and were generally reduced by both autoclaving and cooking. In the most commonly available and consumed marble-colored AYB, autoclaving at 121 ^°C, 15 psi for 20 min decreased cyanogenic glycosides by 46%, oxalate by 48.9%, tannin by 15.0%, saponin by 14.8% and trypsin inhibitors by 61.3% while cooking for 3.5 hours in tap water decreased these toxic factors by 66.5%, 70.3%, 72.2%, 48.7%, and 86.0%, respectively.The results indicate that for raw samples, varietal difference did not significantly affect nutrient composition though the toxicants were generally higher in the brown AYB than the marble-colored. Autoclaving decreased both nutrient value and the level of toxicants in the two seed types; values were further reduced by cooking. Of the toxicants, trypsin inhibitor was found to be the most heat-labile and of the heat treatment methods, cooking to tenderness is recommendable.     

Proximate composition and selected physicochemical properties of the seed,pulp and oil of sour sop (Annona muricata)

Proximate composition and physicochemical analyses were carried out onthe seed, pulp and extracted oil of sour sop (Annona muricata). Theresults showed that the seed contained 8.5% moisture, 2.4% crudeprotein, 13.6% ash, 8.0% crude fiber, 20.5% fat and 47.0%carbohydrate. The seed also contained 0.2% water soluble ash, 0.79%titratable acidity and 17.0 mg calcium/100 g. The pulp was found tocontain 81% moisture, 3.43% titratable acidity and 24.5%non-reducing sugar. Selected physicochemical characteristics includedrefractive indices of 1.335 for the seed and 1.356 for the pulp, specificgravities of 1.250 for the seed and 1.023 for the pulp, pH values of 8.34for the seed and 4.56 for the pulp, and soluble solids contents of1.5 ^°Brix for the seed and 15 ^°Brix for the pulp. Theextracted oil (20.5% yield) had a 60.43% unsaponifiable value,23.54 KOH/g acid value, 100.98 K0H/g saponification value, 1.1 K0H/gperoxide value, 1.464 refractive index, 5.77 pH, 69.5 ^°Brix soslublesolids and 0.2900 specific gravity.     

An Evaluation of the Microflora Associated with Fermented African Oil Bean (Pentaclethra Macrophylla Bentham) Seeds During Ugba Production

The microorganisms associated with fermented African oil bean (Pentaclethra macrophylla Bentham) seed during ugba production was studied. Only bacteria were isolated from the ugba samples used. Although the bacteria included Bacillus spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp. and members of the family Enterobacteriaceae, only the Bacillus spp. were found to ferment African oil bean seeds to ugba. Bacillus spp. were the predominant microorganisms present, constituting over 95% of the total microbial population density. An increase in the number of Bacillus cells of about 2 log units daily, which attained a maximum density of log₁₀ 9.00 - log₁₀ 11.90 cfu/g after 3 days was observed. Contrarily, the Lactobacillus spp. increased minimally and attained a maximum value of log₁₀ 4.20 - log₁₀ 6.35 cfu/g within the same period. The Staphylococcus spp., Micrococcus spp. and the members of the family Enterobacteriaceae remained fairly steady in number for 24h, increased slightly till the 3rd day followed by exponential increases which attained maximum values of between log₁₀ 9.20 - log₁₀ 11.00, about the 7th day. Bacillus spp. cells also had the highest protease activities which were significantly (p < 0.05) higher than the values for the other bacterial isolates. The Bacillus spp. responsible for the fermentation of African oil bean seeds to ugba were identified as Bacillus coagulans, B. macerans, B. megaterium, B. pumilis and B. subtilis.     

Proximate composition and functional properties of four cultivars of bambara groundnut ( Voandezeia subterranea)

Proximate composition and selected functional properties of four cultivars of bambara groundnut ( Voandezeia subterranea Thoura) were ascertained. Crude protein ranged from 17.5 to 21.1 percent; crude fat 7.3–8.5 percent; total ash 4–5 percent; crude fiber 1.8–2.0 percent; carbohydrate and moisture content for the different cultivars were 53.0–60.8 percent and 7.5–12.3 percent, respectively. The results of functional property determinations indicated that the bulk density ranged from 0.65 to 0.75 g/ml; water binding capacity 2.1–2.9 g/2g sample; oil binding capacity 0.9–1.6 g/2g sample; emulsifying activity 55.-1–60.0 percent and emulsifying stability 10–12 percent. The results show that bambara groundnut has great potential for incorporation into various human foods where it could provide useful plant proteins.     

Proximate composition and antinutritional factors in rice bean (Vigna umbellata)

Thirteen promising strains of Rice bean (Vigna umbellata) were analysed for their proximate compositions and antinutritional factors. Protein content in these varieties ranged from 17.50 to 23.10 per cent, ash from 3.06 to 4.48 per cent, ether extract from 2.4 to 3.9 per cent and crude fibre from 1.70 to 4.25 per cent. Trypsin inhibitor activity ranged from 112.63 to 163.98 units/g and polyphenols ranged from 0.58 to 1.19 per cent. Phytohemagglutinating activity was present in all the strains, except one, RB-32. Oligosaccharides, viz., raffinose, stachyose and verbascose, ranged from 0.32 to 0.91, 0.95 to 1.98 and 1.40 to 2.58 per cent, respectively. Attempts have been made to compare the results with a standard variety each of cowpea (Vigna unguiculata), moong (Vigna radiata) and mash (Vigna mungo).     

Influence of heat processing of African yam bean seed (Sphenostylis stenocarpa) flour on the growth and organ weights of rats

The influence of heat processing of African yam bean seed flour on the growth and organ weights of rats was studied. Body weight change, feed utilization and feed conversion ratio were improved by heat processing. All rats significantly (p0.05) gained weight except those fed raw African yam bean and basal diets (diets 3 and 1 respectively). Raw African yam bean diet decreased the growth of rats and had negative effect on the organ weights especially the pancreas which was enlarged. The results indicate that heat processing improved the growth of rats and organ weights due to heat inactivation of toxic factors especially trypsin inhibitors.     

Effect of processing on nutrient composition and anti-nutritive substances of African locust bean (Parkia filicoidea) and baobab seed (Adansonia digitata)

The effects of various processing techniques on nutrient composition and anti-nutritional factors in baobab seeds (Adansonia digitata L.) and locust beans (Parkia filicoidea L.) were investigated. The methods used for processing include boiling in water, acid or alkali and fermentation. Using the water treated samples as controls, there were slight decreases in protein and carbohydrate contents of the fermented and alkali-treated meals. However, an increase in extractable oil content was observed in acid, alkali and fermented samples. The alkali treatment appeared to be the most effective method for reducing trypsin inhibitor and tannin contents and has the additional advantage of improving the protein digestibility.     

Influence of pH and sodium chloride on selected functional and physical properties of African breadfruit (Treculia africana Decne) kernel flour

African breadfruit seeds were cleaned, parboiled (98 ^°C) for 15min, drained and dehulled. The kernels were sun-dried, then milled andsieved into flour. Nitrogen solubility (NS), water absorption capacity(WAC), emulsion activity (EA), viscosity, foaming and emulsifyingproperties of the flour were determined as functions of pH and NaClconcentration. The NS was pH dependent with a minimum at pH 4 andmaximum at pH 10. The flour also exhibited minimum and maximum foamcapacity at pH 4 and 10, respectively. The minimum emulsion activity wasat pH 4, a value which increased from 7–16% at pH 12. The addition ofNaCl at concentrations of 0.2 to 0.4 M improved WAC, NS, foamingand emulsion properties of the flour. Sodium chloride enhanced NS of theflour at pH 4–6 and EA at pH 2–8.The EA at pH 2, 10 and 12 correlated negatively (r = –0.30) with NaClconcentration levels; however, the correlation was not significant (p> 0.05). The flour dispersions had lower viscosities at acid pH and in thepresence of NaCl than at neutral and alkaline pH values. Results indicatedthe flour could be used in food product supplementation.     

Chemical and sensory evaluation of vegetable milks from African yam bean Sphenostylis stenocarpa (Hochst ex A Rich) Harms and maize (Zea mays L.)

Vegetable milks were developed from fermented and unfermented African yam bean (AYB) flours and their maize blends. AYB was cleaned, dehulled, milled and fermented for 24 hours by the natural microflora present in the legume flour. Maize was fermented for 48 hours. A ratio of 70:30 (protein basis) of AYB: maize was used to formulate the blends. Vegetable milks were prepared from the AYB flours and their maize blends. Standard assay techniques were used to evaluate the milks for proximate, mineral, ascorbate and antinutrient composition. The protein contents of the milks (1.47–2.06 percent) was comparable to soymilk (2.04 percent) and bambara groundnut milk (2.00 percent). The milks contained appreciable quantities of carbohydrate and minerals tested. The milk blends had traces of ascorbate and contained higher phosphorus than the milks from the AYB flours. The fermented milk blend had higher protein, ash and sugar levels and lower phytate and stachyose levels compared to non-fermented blend. Raffinose was reduced to trace levels in the fermented milks. The milks were appetizing. The fermented milk blend was more acceptable than others and was preferred in terms of flavor and color. It had greater advantages over the other vegetable milks evaluated in terms of zinc, phosphorus and stachyose levels.     

Effects of debittering methods on the proximate composition,organoleptic and functional properties of sesame (Sesamum indicum L.) seed flour

Sesame seeds were boiled and allowed to sprout under ambient condition (30±2 °C) with an objective to reduce or eliminate the bitter taste associated with them. The untreated seeds were used as a control. The proximate composition, functional and organoleptic properties of defatted sesame flour were assessed at room temperature. There was a slight increase (about 10%) in protein content of sprouted seeds. The foaming capacity of flours from untreated, sprouted and boiled seeds were 34.6, 38.5 and 11.5%, respectively. The flour from the boiled seeds had the highest foam stability. Flours from untreated or sprouted seeds, gelation started at the least concentration of 6% whereas that from boiled seed was 11%. The emulsion capacity of flours from the untreated or sprouted seeds was the same (27.6 g oil/g sample) while that from boiled seeds was 12.9 g oil/g sample. Emulsion stability with prolonged storage appeared to be more with flours from the sprouted or boiled seeds than that from the untreated ones. The water absorption properties of flours from the untreated, sprouted and boiled seeds were 8.0, 5.9 and 6.5 g H₂O/g sample, respectively whereas the oil absorption capacity same (5.9 g oil/g sample). The bitter taste in flours from the untreated or sprouted was high. The bitter taste was not detected in flour from boiled seeds and the functional properties of the flour were not deleteriously affected except foaming and emulsion capacity. Therefore, this boiling method of debittering sesame seed could be practised. The quality of sesame flour obtained with this boiling method could still serve its role in traditional dishes and in the formulation of some other conventional food products.     

Chemical composition and nutritional potential of yam bean seeds (Pachyrhizus erosus L. Urban)

Pachyrhizus erosus seeds were analysed for proximate composition, minerals, protein fractions, antinutritional factors, and rotenoids. The seeds showed a high content of proteins, lipids, Fe and Ca, in comparison to other legumes. Glutelins constitute the highest protein fraction, followed by globulins. Antinutritional substances detected as tannins, hemagglutinating activity and trypsin inhibitory activity, were in low concentrations. Seeds were also processed to obtain a flour which showed proper characteristics, good in vitro digestibility, significant rotenoid reduction level and amino acid composition rich in essential amino acids, except methionine.     

Effect of processing on flatus producing oligosaccharides in cowpea (Vigna unguiculata) and the tropical African yam bean (Sphenostylis stenocarpa)

The effect of dehulling, soaking and soaking/cooking on sucrose, raffinose and stachyose in mature dry seeds of nine varieties of cowpea (Vigna unguiculata) and one variety of tropical African yam bean (Sphenostylis stenocarpa) were investigated. The results showed a progressive decrease in sucrose, raffinose, and stachyose contents. Soaking for 12 hours and cooking for 30 min eliminated most of the sucrose, raffinose and stachyose. The sugar contents in whole raw cowpea were sucrose 0.73–4.58%, raffinose 0.71–6.86% and stachyose 2.38–3.87%, and for tropical African yam bean sucrose 4.08%, raffinose 1.08% and stachyose 4.14% while the seeds soaked for 12 hours and cooked for 30 min had for cowpea sucrose 0.03–0.81%, raffinose 0.04–0.20% and stachyose 0.12–0.72%, and tropical African yam bean sucrose 0.70%, raffinose 0.40% and stachyose 0.41%.     

An evaluation of the effect of Bacillus cells and Bacillus spores in association with cowpea granules as starter cultures for the fermentation of African oil bean (Pentaclethra macrophylla Bentham) to `ugba'

Studies on the improvement of the traditional production of `ugba',a protein-rich fermented African oil bean seed product, were undertaken,by developing starter cultures of Bacillus subtilis cells andspores in association with cowpea granules. The viability of the cellsin association remained stable at 94.5% for 6 months at 30 <sup>°</sup>C and for up to 10 months at 4 <sup>°</sup>C while the viability of the sporesin association remained stable at ca. 96% for up to 10 months at both4 and 30 <sup>°</sup>C. The starter cultures resulted in high increases inprotease activity from ca 2.8 mg N/min to about 51.6 ± 0.4 mg N/minin 48 h and a corresponding increase in amino-nitrogen content of ca2.0 ± 0.2 mg N 100 g dry matter (DM) to ca 18.5 ± 0.3 mg N/100g (DM) during the same period. Changes in the protease activity of thenatural process were gradual and increased from 3.0 mg N/min to 38.0 ±0.8 mg N/min after 5 days of fermentation. The maximum amino nitrogencontent of `ugba' produced by the starter cultures (18.5 ± 0.3 mgN/100 g DM) after 2 days was significantly (p < 0.05) higher than themaximum amino nitrogen content (12.5 ± 0.8 mg N/100 g DM), of `ugba'obtained by the natural process. `Ugba' produced by the starter cultureswere well accepted and compared favorably with the natural product.     

Chemical composition and profile characterisation of pumpkin (Cucurbita maxima) seed oil

Seeds of a Tunisian variety (Béjaoui) of pumpkin (Cucurbita maxima) were analysed for their main chemical composition and for their oil properties. Expressed on dry weight basis, seed moisture was 8.46%, whereas contents of proteins, fibre, ash, fat, and total sugars established at 33.92%, 3.97%, 21.97%, 31.57%, and 0.11% respectively. Gas chromatography revealed that the major fatty acids were oleic, linoleic, and palmitic acids (44.11%, 34.77%, and 15.97% respectively). Seed oil was also found to be rich in tocopherols with a predominance of δ-tocopherol (42.27%). The sterol marker β-sisosterol accounted for 39.6% of total sterols contained in seed oil of this variety. Six phenolic acids (protocatechuic, caffeic, syringic, vanillic, p-coumaric and ferulic) were detected, the syringic acid being predominant (7.96 mg/100 g). As a whole, based on its seed oil features, pumpkin may be considered as a valuable source for new multi-purpose products for industrial, cosmetic, and pharmaceutical utilisation.     

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

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.     

Production of African breadfruit (Treculia africana) and soybean (Glycine max) seed based food formulations, 2: Effects of germination and fermentation on microbiological and physical properties

The effects of germination (G) and naturally fermented (F)on the bacterial flora, viscosities and moisture sorptionisotherms of soybean (S) and African breadfruit (B) seed based food products were investigated. Bacillus,Enterobacter, Enterobacteriaceae, Proteus, Serratia andStaphylococcus species dominated in the nonfermentedproducts. Lactobacillus, Leuconostoc, Pediococcusand yeast species dominated in the fermented products whosegruels also inhibited growth of coagulase positive Staphylococcus aureus in challenge tests. Germination andfermentation resulted in significant (p < 0.05) decreasesin cooked paste viscosities which is advantageous inincreasing nutrient density. The monolayer moisture contents (g H₂O/g solid) and surface areas for monolayer adsorption (m²/g solid) derived from BETmodel were 0.0422 and 148.1 (GFSB); 0.0428 and 150.4 (NGFSB); 0.0436 and 153.3 (NGNFSB); 0.0531 and 186.6 (GNFSB), respectively.     

European pennyroyal (Mentha pulegium) from Portugal: Chemical composition of essential oil and antioxidant and antimicrobial properties of extracts and essential oil

There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The aim of this study was to determine the chemical composition of European pennyroyal (Mentha pulegium) essential oil and to characterize the in vitro antioxidant and antimicrobial activities of its water (hot and cold) and ethanolic extracts and of the essential oil. The essential oil revealed menthone, pulegone and neo-menthol as the main constituents, comprising 35.9, 23.2 and 9.2% of the essential oil, respectively. The hot water extract exhibited the highest antioxidant activity and phenol content. In contrast, the extracts were not very effective to inhibit the growth of the seven foodborne spoilage and pathogenic bacteria tested, but the essential oil showed antibacterial activity against all bacterial strains. In conclusion, extracts and essential oil of M. pulegium from Mediterranean origin have huge potential as an alternative to chemical additives for the food industry.