Nutritive value of baobab milk (gubdi) and mixtures of baobab (Adansonia digitata L.) and hungry rice,acha (Digitaria exilis) flours

The baobab milk and fermented baobab/acha flour mixtures were analyzed chemically for their proximate, ascorbate, mineral and antinutrient composition. The dry pulp scraped from baobab fruits was kneaded, made into solution, extracted through cheese-cloth and stored frozen until analyzed. The acha and baobab grains were cleaned, fermented for 24 to 120 hours, dried and hammermilled into fine flours. The unfermented flours served as controls. The standard assay methods of AOAC were selected for use for the analysis of the nutrients and the antinutrients. The mixtures were composed of 70% acha and 30% baobab flours (70:30 protein basis). The baobab milk contained more protein (1.5%) and minerals (Fe, 17.8 mg; Ca 134.2 mg) than those of human milk (protein, 1.3%, Fe, 0.2 mg, Ca 30 mg) and cow milk (Fe, 0.1 mg; Ca 1.20 mg) and most leading national commercial infant formulas e.g. cerelac (Fe, 10.0 mg). The composite flours contained more nutrients than the baobab or the acha flour alone. The BF96 had greater advantage over other BF flours as a supplement to acha. The mixtures are within the reach of lower income group and can be incorporated into their diets.     

Proximate composition and selected functional properties of fermented and unfermented African oil bean (Pentaclethra macrophylla) seed flour

Flour samples were prepared from fermented and unfermentedAfrican oil bean (Pentaclethra macrophylla) seeds (AOBS). The flour samples were evaluated for proximate composition and certain functional properties. The influenceof defatting on these properties was also determined. Fermentation significantly increased (p<0.05) the proteinand decreased the crude fiber, ash, fat and carbohydrate contents of the AOBS flours. The nitrogen solubility of both fermented and unfermented flours was pH dependent withminimum and maximum solubility at pH 4.0 and pH 8.0, respectively, and with increased nitrogen solubility in the fermented sample. The fermented and unfermented flour sampleshad least gelation concentrations of 14 and 16% (w/v), respectively. The water absorption capacity and foam capacitiesof the fermented flour were 36 and 34%, respectively, over the unfermented seed flour. On the other hand, fermentation decreased the fat absorption capacity, emulsion activity and emulsion and foam stabilities. Fermentation decreased (p<0.05) the bulk density of AOBS flour by 15%. Defattingimproved all the functional properties evaluated except emulsion activity. These results indicate potential food usesof fermented and unfermented AOBS flour samples as protein supplements in diets and as functional ingredients in formulated foods.     

Effect of domestic processing,cooking and germination on the trypsin inhibitor activity and tannin content of faba bean (Vicia faba)

The effects of domestic processing methods like soaking for 12 h dehulling, ordinary cooking of whole as well as dehulled seeds at 151bs/inch² pressure for 15 and 25 min, and germination for 24, 36 and 48 h were observed on trypsin inhibitor (TIA) and tannin content of two varieties of faba bean viz. VH-131 and WF. A non-significant reduction in TIA was observed on soaking and dehulling, while tannins showed a reduction of 42 and 51% on soaking in VH 131 and WF, respectively. Dehulled seeds showed a decline in tannin content by 70 to 73% in two varieties. There was a significant reduction in TIA (75–76 per cent) and tannin (76–81%) on cooking, while autoclaving for 25 min almost completely eliminated both of these stress factors. Germination of seeds for 48 h led to a reduction of 64–65% in TIA and 90–91% in tannins, which was more than germination for 24 and 36 h. Soaked seeds gave positive results of both these antinutrients.     

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.     

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 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%.     

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 heat treatments and germination on trypsin inhibitor activity and polyphenols in jack bean (Canavalia ensiformis L. DC)

The application of dry heat to seeds and meal was not effective in inactivating the TI and reducing the polyphenol content. Soaking for 24 h followed by cooking for 20 min, was equally effective in destroying the TI activity. Germination of jack bean seeds for 40 h decreased the levels of TI and polyphenols by 31% and 35%, respectively.     

Effect of thermal treatments on the chemical and biological value of irradiated and non-irradiated cowpea bean (Vigna unguiculata L. Walp) flour

Chemical and nutritional characteristics of irradiated and nonirradiated cowpea bean at 0.2 kGy submitted to several thermal treatments were studied. The cowpea bean flours irradiated at 0.2 kGy were superior to those non-irradiated concerning digestibility and the flours submitted to microwave oven were superior to those cooked under low pressure, autoclaved or even raw from the nutritional point of view. As to the presence of anti-nutritional factors, the results showed that the variety of cowpea bean under research presented neither trypsin inhibitor nor haemagglutinin activity, however, regarding tannin, a 0.006% content was found and considered negligible.     

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.     

Production of African bread-fruit (Treculia africana) and soybean (Glycine max) seed based food formulations, 1: Effects of germination and fermentation on nutritional and organoleptic quality

Germination and fermentation were investigated as methods of improving the nutritional and organoleptic properties ofsoybean and African breadfruit seed based food formulations.Four products consisting of germinated-fermented soy-breadfruitseeds (GFSB), nongerminated-fermented soy-bread-fruit seeds(NGFSB), germinated-nonfermented soy-breadfruit seeds (GNFSB)and nongerminated-nonfermented soy-breadfruit seeds (NGNFSB)were prepared. Phytic acid contents, in vitro protein digestibilities, protein efficiency ratios (PER), net proteinratios (NPR), flavor, appearance and overall acceptabilitywere evaluated. Germination followed by natural lactic fermentation significantly (p < 0.05) reduced the phytic acid by a factor of 11.6 in NGNFSB compared to reductionfactors of 2.1 and 1.5 in GNFSB and NGFSB, respectively.The in vitro protein digestibility (%), PER and NPR valuesof 73.4, 2.46 and 3.62 for GFSB; 71.1, 2.35 and 3.46 for NGFSB;68.7, 2.16 and 3.41 for GNFSB were significantly (p < 0.05)higher than the 64.7, 1.82 and 2.11 for NGNFSB. The meansensory scores were 5.26–5.67 for GNFSB, 4.66–4.94 forNGNFSB, 4.33–4.80 for GFSB and 4.27–4.34 for NGFSB on a7-point rating scale.     

Effect of plant development during first and second growth cycle on chemical composition,condensed tannins and nutritive value of three sainfoin (Onobrychis viciifolia) varieties and lucerne

Sainfoin (Onobrychis viciifolia) is a temperate legume that contains condensed tannins (CT), i.e., polyphenols that are able to bind proteins and thus reduce protein degradation in the rumen. Few studies have investigated the relation between plant phenology, CT characteristics and nutritive value of sainfoin. In this study we investigated differences among three sainfoin varieties (Esparcette, Ambra and Villahoz) that were of different geographical origin, and which were cultivated at the same site over the course of two growth cycles and compared with a tannin‐free legume, lucerne (Aubigny). Plants were harvested on nine dates in the first and four dates in the second growth cycle. Phenological stages were analysed for leaf‐to‐whole‐plant ratio, nitrogen (N), organic matter digestibility (OMd) by the pepsin‐cellulase method, cell‐wall concentration, N solubility (solN) plus CT concentration, biological activity and structures. Leaf‐to‐whole‐plant, cell‐wall concentration, N of sainfoin and lucerne were closely related to the phenological stage. Although sainfoin developed earlier than lucerne, its pepsin‐cellulase digestibility was higher than or close to lucerne. Esparcette had the lowest OMd, N and solN and the highest CT concentration. CT concentration, proportion of prodelphinidins (PD) and mean degree of polymerization (mDP) increased with the phenological stage (or plant maturity), and these parameters were associated with lower biological activity of CT. Sainfoin varieties differed in their relationships between phenological stages, nutritional parameters and CT characteristics. The results demonstrated that sainfoin can be a valuable alternative forage legume to lucerne.     

Effect of soaking,sprouting, fermentation and cooking on nutrient composition and some anti-nutritional factors of sorghum (Guinesia) seeds

This study was designed to determine the effect of soaking, sprouting, fermentation and cooking on nutrient composition and some antinutritional factors of sorghum seeds (guineesia). Standard assay procedures were adopted to resolve both the nutrients and the antinutritional factors content of the products. Combination of cooking and fermentation improved the nutrient quality and drastically reduced the antinutritional factors to safe levels much greater than any of the other processing methods tested.     

Effect of heat processing on in vitro protein digestibility and some chemical properties of African breadfruit (Treculia africana Decne) seeds

The effects of dry heat (roasting) and moist heat (boiling) on in vitro protein digestibility, protein fractions and other chemical properties of African breadfruit (Treculia africana Decne) seed that affect their utilization as a source of human food were investigated. Chemical analyses showed that the crude protein and fat contents of the unprocessed (raw) seeds were 20.1% and 13.7%, respectively. The level of phytic acid in the raw seed (1.19 mg/g) was lower than the levels found in some commonly consumed pulses in Nigeria. Albumin and globulin protein fractions were found to be the major seed proteins of African breadfruit seed, constituting 67.8% of the total protein of the raw seed. There were no significant (p<0.05) differences between crude protein, ash and fat contents of the raw and heat processed samples. Boiling proved more effective than roasting for improving protein digestibility and for reducing the levels of trypsin inhibitor, phytic acid and polyphenols of the samples. The complete removal of these antinutrients, however, would require a more severe heat treatment of the seed, which in turn would profoundly reduce the nutritional value and availability of proteins, as demonstrated by the low values obtained for in vitro protein digestibility, protein fractions and protein extractability.