African Yam Bean Seeds Research Articles

Phytotoxic effect of Carica papaya extract on seed-borne fungus of African Yam Bean (Sphenostylis stenocarpa Hochst ex. A. Rich. Harms) seeds

Extracts of many higher plants have been reported to exhibit antifungal properties under laboratory experiments. This study was therefore carried out to investigate the effect of Carica papaya plant extracts on the African Yam Bean seed-borne pathogen. The seed health test of African Yam Bean was carried out using the blotter paper method. The experiment was conducted at the Plant Pathology Laboratory of the Department of Crop Science and Horticulture, Nnamdi Azikiwe University, Awka. Test of plant extract for inhibition of radial growth of seed-borne pathogen of African yam bean was studied under in vitro experiment at 0%, 50%, 75% and 100% concentrations with 0% as the control. The design was a Completely Randomized Design (CRD) with three replications. The test plant extracts of different concentrations were added into Petri dishes containing molten-sterilized Sabouraud Dextrose Agar (SDA) and swayed gently on the laboratory bench to allow an even mixture These were allowed to gel. Then nine millimeter discs of a seven-day pure culture of Aspergillus flavus were aseptically placed on the centre of the Petri dishes containing the SDA-extract mixture. Records on the radial inhibition effect of the test plant extract were kept for further analysis. Data on radial inhibition of fungus were subjected to Analysis of Variance (ANOVA). Results showed that Aspergillus niger, Aspergillus flavus and Aspergillus terreus were isolated from incubated African Yam Bean seeds. Carica papaya leaf extract used was very effective and the higher the concentrations of extract, the more effective in the inhibition of radial growth of the test fungus. It could therefore be recommended that farmers should always conduct viability tests on procured seeds before planting. Farmers should rather use plant extract such as the one used in this experiment in controlling seed-borne fungal pathogens of African Yam Bean seeds than synthetic fungicides.

Antioxidant, Anti-diabetic and Sensory Properties of Bread Produced from Flour Blends of Wheat and Pretreated African Yam Bean and Bambara Groundnut Seed Coat

Antioxidant, Anti-diabetic and Sensory Properties of Bread Produced from Flour Blends of Wheat and Pretreated African Yam Bean and Bambara Groundnut Seed Coat

Effects of thermal processing on the nutritional and antinutritional properties of African yam bean (Sphenostylis stenocarpa) seed flours

The study was carried out to evaluate the effects of thermal processing treatments on nutrient and antinutrient contents of African yam bean seed flours. The African yam bean seeds were sorted, cleaned and divided into five equal lots of one kilogram each. Four lots were processed into boiled, blanched, roasted and autoclaved African yam bean flours, while the last lot was processed raw and used as control. The flour samples obtained were analysed for proximate, mineral, vitamin and antinutrient contents using standard methods. The proximate composition of the samples revealed that the flours had a range of 6.14-11.24% moisture, 8.18-14.37% crude protein, 3.06-4.61% fat, 2.04–3.32% ash, 3.18–3.56% crude fibre, 62.90–76.98% carbohydrate and 350.57–368.50 kJ/100g energy, respectively. The mineral composition of the samples showed that the flours contained 128.81–174.16 mg/100g calcium, 88.86–212.20 mg/100g, potassium, 134.71–166.77 mg/100g phosphorus, 89.17 – 122.76 mg/100g, magnesium, 14.28–18-11 mg/100g iron and 3.24–5.59 mg/100g zinc, respectively. The vitamin composition of the flours were 1.15–1.37 mg/100g ascorbic acid, 1.15–135 mg/100g thiamine, 1.19–1.55 mg/100g niacin, 1.34–1.85 mg/100g riboflavin, 1.09–1.29 mg/100g folic acid, 1.37–1.95 mg /100g vitamin A and 1.27–1.66 mg/100g vitamin E, respectively. The results showed that the roasted and autoclaved African yam bean flours generally had higher crude protein, fat, ash, crude fibre, mineral and vitamin contents than the boiled and blanched flour samples compared to the raw sample. The antinutrient composition of the flours also showed that the levels of trypsin inhibitor activity, tannin, phytate, oxalate, saponin and haemagglutinin of the samples were significantly (p<0.05) reduced by boiling, autoclaving roasting and blanching treatments compared to the raw sample. However, the study revealed that the processed African yam bean flours have the potentials to be used as nutrient dense ingredients in the preparation of a wide range of food products than the raw sample especially in both underdeveloped and developing countries where the problems of protein-energy malnutrition and micronutrients deficiencies are prevalent.

Quality Characteristics and Sensory Properties of Bread Elaborated with Flour Blends of Wheat and African Yam Bean

This study evaluated quality characteristics and sensory properties of bread elaborated with flour blends of wheat and African yam bean. The wheat flour was procured, while the purchased African yam bean seeds were cleaned, sorted, washed and steeped in 2.5 litres of clean water for 12 h with intermittent changing of soaking water at 3 h intervals, drained, sprayed on moistened jute bag spread on malting table and covered with moistened jute bag. The seeds were germinated for 72 h with occasional sprinkling of water. Thereafter, harvested imbibed seeds were dried in a hot air oven at 60⁰C for 12 h and converted into flour with attrition mill. Wheat flour and African Yam Bean flour were sieved individually with 60 mm mesh size sieve. The flours were blended in the percentage ratios (W: W) of 100:0, 90:10, 80:20 and 70:30 for samples A, B, C and D, respectively. Three grams of yeast (Saccharomyces cerevisiae, Foshan Ceng Goa Food Co. Ltd, De Rich Instant Dry) were dissolved in clean bowl with 30 l of water and 10 g sugar of the stipulated receipe and left for 1 h to activate at ambient temperature (29 ± 1⁰C). The flour blends were evaluated for proximate composition, functional properties and consumer acceptability. Preference ranking tests were conducted to describe and evaluate the acceptability of the bread loaves according to hedonic scale on texture, flavour, colour and overall acceptability using a 9-point, where1 = dislike extremely and 9 = extremely like. The data generated were analyzed statistically using one way analysis of variance and means separated by Tukey test at 5% level of Significance. The results showed that sample D – 30% substituted African yam bean flour had higher swelling index (1.81g/g), water absorption capacity (160.00%), protein content (14.89 %), fat content (2.80%), panelists textural scores (6.55) and the least flavour scores (4.05),colour scores (5.70) and overall acceptability scores (3.85) compared to other samples. There were no statistically significant differences (p > 0.05) in overall acceptability scores of samples B, C and D. The overall acceptability scores showed that samples acceptance decreased with increased levels of substitution with African yam bean seed flour.

Amino acid profile and protein quality of starter cultures fermented African Yam bean (Sphenostylis sternocarp) seed condiment

African yam bean seeds condiment is an unpopular nutritive local food seasoning compared to Iru and is mostly produced by natural fermentation. Production with a defined starter culture will give a novel functional condiment with enhanced nutritive values, especially amino acids, to prevent hidden hunger, shorten the fermentation time, and improve product uniformity. The effect of different monoculture bacterial starters and natural fermentation on the amino acids profile of condiments produced from African yam bean seeds was investigated. The result revealed a total of 18 amino acids with glutamic and aspartic acids as the most abundant amino acids in all the samples portions, with a range of values of 9.79-11.44 g/100 g protein and 9.20 -10.67 g/100 g protein respectively. The inoculated samples were rich in all the amino acids quality than un-inoculated. The total amino acid content of the samples was significantly different (p ≤ 0.05). Bacillus amyloliquefacien starter fermented sample had the highest total amino acid value of 95.80 g/100 g protein while Bacillus subtilis fermented and un-inoculated seed portion samples had a total amino acid value of 86.81 g/100g and 74.04 g/100 g protein respectively. The essential amino acids (EAA10) were significantly different (p ≤ 0.05) and were in the range of 35.75-46.32 g/100 g protein with leucine, arginine, lysine, valine, isoleucine and phenylalanine the most abundant in inoculated and un-inoculated samples portions and were more concentrated in inoculated samples. Non-essential amino acids were slightly higher (38.29 - 49.47 g/100 g protein) than the total essential amino acids. The total acidic amino acids varied from 18.99 – 22.11 g/100 g protein and were significantly higher than the basic amino acids (12.88 – 15.95 g/100 g protein). The amino acid content of the Bacillus amyloliquefacien starter fermented sample was better enhanced than the sample fermented with Bacillus subtilis starter. The study concluded that controlled fermented condiments produced with B. amyloliquefacien culture boosted the amino acids value and profile.

Nutrients, the Bioavailability of Micronutrients and Antinutrient Composition of African Yam Bean Tubers

Despite the huge nutritional and nutraceutical benefits associated with the consumption of African yam bean (AYB) seeds, AYB tubers are still underutilized in Nigeria, they are left to rot in farmers’ fields. To create awareness about their nutrient density and provide information on the bioavailability of micronutrients in the tubers of AYB accessions, raw tubers of TSs 9, TSs 60 and TSs 93 were analyzed using standard laboratory procedures. The AYB tubers had the following composition on a fresh weight basis: crude protein (7.55-8.27%), carbohydrate (9.36-11.12%), crude fat (0.18-0.22%), crude fibre (0.33-0.750%), crude ash (0.44-0.59%), and moisture (79.76-80.82%). The fresh tubers were rich in minerals: potassium (532.88-557.80 mg/100 g), calcium (205.75-467.50 mg/100 g), magnesium (124.75-168.50 mg/100 g), iron (15.71-27.30 mg/100 g), zinc (8.57-14.80 mg/100 g), and manganese (0.68-1.98 mg/100 g). The phytate: Zn and the phytate: Fe molar ratios indicated the bioavailability of Fe and Zn in the raw AYB tubers. The results of this study indicate that AYB tubers are good sources of protein, energy and bioavailable Fe and Zn and should be utilized for human diets and livestock feed. With good processing, AYB tubers could contribute to food and nutrition security. There is a need for research on food products developed from AYB tubers to enhance their utilization and large-scale production in Nigeria.&nbsp

EFFECTS OF BACILLUS AMYLOLIQUEFACIENS CULTURE CONCENTRATIONS ON MICROBIAL LOAD, PHYSICOCHEMICAL AND SENSORY PROPERTIES OF “IRU”-TYPE CONDIMENT FROM AFRICAN YAM BEAN (SPHENOSTYLIS STENOCARP) SEEDS

African yam bean seeds (Sphenostylis sternocarpa) Iru-like condiment was produced with 0.005 and 0.0075 g broth/g seed different concentrations of Bacillus amyloliquefaciens culture. The sample fermentation was conducted at 35 °C for 5 days. Proximate composition, water absorption capacity, oil absorption capacity, pH, and titratable acidity of the fermented samples were assessed using standard methods. Proximate composition of fermented African yam bean (AYB) condiment with 0.005 g broth/g seed inoculum concentration as determined were crude protein (6.86%-7.74%), crude fat (1.37%-1.71%), crude fiber (2.73%-4.81%), ash content (1.02%-1.59%), moisture content (9.71%-14.92%), dry matter (85.10%-90.28%), carbohydrate (70.43%-77.16%). The pH, total titratable acidity, water absorption capacity (WAC), and oil absorption capacity (OAC) of the fermented condiment were 6.76-7.60 ml, 0.07-0.09 ml, 0.50%-0.92%, and 0.55%-0.65% respectively. The fermented condiment produced with 0.0075 g broth/g seed inoculum concentration had its proximate composition as determined as crude protein (8.10%-8.53%), crude fat (1.81%-2.12%), crude fiber (2.83%-3.73%), ash content (1.23%-1.42%), moisture content (8.97%-12.81%), dry matter (87.19%-90.91%), carbohydrate (72.22%-76.13%) while its pH, total titratable acidity, WAC and OAC ranged as 7.10-8.76 ml, 0.06-0.11 ml, 0.38%-0.81% and 0.54%-0.84% respectively. The sensory acceptability scores reveal condiment samples from 0 hours as the best-preferred sample produced from the use of the inoculum concentrations. The study showed that AYB seeds condiments produced were significantly different in terms of different concentrations of starter culture used. Although the single starter culture did not deliver acceptable products during the fermentation, it played a few parts within the product quality.

Evaluation of Pasting and Functional Properties of Flour Blends Made from African Yam Bean (Sphenostylis stenocarpa) and Corn (Zea mays) Seeds

Evaluation of Pasting and Functional Properties of Flour Blends Made from African Yam Bean (Sphenostylis stenocarpa) and Corn (Zea mays) Seeds

Chemical composition, sensory and microbial attributes of porridges prepared from African yam bean (Sphenostylis stenocarpa) and corn (Zea mays) flour blends

Background: The dietary challenges facing type 2 diabetics have necessitated the development of high fiber indigenous diets for the management/control of blood glucose.
 Objectives: The study determined the chemical composition, sensory and microbial attributes of porridges prepared from African yam bean (AYB) and corn flour blends.
 Methods: AYB seeds roasted at 1910C for 40 min and corn oven-dried at 500C for 24 h were finely milled, evaluated for proximate composition and dietary fiber profile and formulated into 5 flour samples in the ratios of 100, 70:30, 50:50, 30:70, 100 to supply one-third (1/3) of the daily dietary fiber requirement (12.7 g) of a reference man (70 kg). The 5 samples (including 3 composites) together with the control (traditional corn flour) provided 6 samples for the study. The samples were made into porridges and evaluated for chemical composition, sensory and microbial attributes using standard procedures. Data generated were analyzed using the IBM Statistical Product for Service Solution statistics version 21. Results were presented as means and standard deviations, Analysis of variance (ANOVA) was used to compare the means and significance was accepted at p < 0.05.
 Results: The proximate, minerals, vitamins and phytochemical compositions of the porridges were superior to the traditional corn porridge (control). No anti-nutrients were detected in all the porridges. Flavonoids (0.01 to 0.04 mg) and saponins (0.01 to 0.05 mg) were present in the porridges but not in the control. Viable organisms (Staphylococcus aureus, Bacillus cereus, Micrococcus spp, Enterobacter aerogenes, Pencillum spp. Rhizopus spp.) that were unnatural microfloral of AYB and corn seeds were detected in the porridges. The microbial loads (1.2 x 101 to 2.0 x 102 cfu/g) were within the acceptable International Commission on Microbiological Specification of food limits of 105 cfu/g. More coliforms and fungal growth were observed in porridges with higher proportions of corn. All porridges rated higher (5.08 - 6.67) on the acceptability scale than the traditional corn porridge (4.00).
 Conclusion: The high-fiber AYB-corn porridges had improved nutrient content, safe microbial load and consumer acceptability than the traditional corn porridge, and will add variety to diabetic meals.

Screening of African Yam Bean Accessions for Imbibition and Seed Physiological Quality

African yam bean is a nutritionally-important but neglected food crop with several health benefits. But its large scale cultivation and consumption are still limited by lack of systematic genetic improvement and breeding programme for the crop. Preliminary studies have established that the inherent field establishment potential of African yam bean is low. Hence the need to screen available accessions to identify those with outstanding seed physiological qualities for selection as parental materials for further improvement. Thirty-four African yam bean accessions were collected from different farmers in five states of Southeastern Nigeria. Seed physiological quality (viability and vigour) was assessed using hundred seed weight, water imbibition, standard germination, accelerated ageing and conductivity tests. The mean squares due to varietal effect were significant (p < 0.05) for germination index and highly significant (p < 0.01) for all other traits. Accessions ENAGag, ENAGmg 1 and, ENAGmg 2 had high standard (> 80%) and accelerated ageing (> 70%) germination percentages. Only 11 of the accessions had an accelerated ageing germination percentage of above 50%. All but one of the 34 accessions had conductivity values less than 5.00 µScm-1 g-1. On the average, African yam bean seeds require up to 76.9% moisture of their initial weight over a period of approximately 53 hours prior for the commencement of germination process. Accessions ENAGag, ENAGmg 1, ENAGmg 2, ENNKob, ENNSog, IMISis, IMOKeo 1 and IMOKeo 3 were outstanding and are therefore potential candidates for genetic improvement of seed quality in African yam bean.

Chemical Composition, Anti-Nutritional Factors and Pasting Properties of Cassava-African Yam Bean Flour Blends for Noodle Preparation

Noodle consumption has been increasing in Nigeria as a result of rapid urbanization, increase in population growth, and desire for convenience food. Noodles are produced from wheat our which is not grown in Nigeria. In order to reduce wheat imports and improve utilization of local crops, various options have been developed to replace wheat flour partially or wholly in noodle production. This study was aimed at optimizing the level of major ingredients to obtain the best flour blend for noodle preparation with optimum nutritional quality. Pro-vitamin A cassava roots (Manihot esculenta Crantz) and African yam bean seeds (AYB) (Sphenostylis stenocarpa) were processed into ours. The ranges of these flours, based on preliminary findings, were computed into a central composite design of Response Surface Methodology (RSM) to obtain 13 flour blends with five central points. The chemical compositions, anti-nutritional factors, and pasting properties of these flour blends were analyzed and measured. By maximizing total β-carotene, protein content, and minimizing fat content, the predicted model indicated the optimum blend of 70.52% cassava flour to 29.48% AYB flour. The best our blend sample of 69.23% cassava our to 30.77% AYB flour gave the actual value of total β-carotene 6.76 μg/g, with proximate analysis composition of protein 6.17%, fat 0.82%, moisture 8.95%, ash 1.77%, crude fiber 5.09%, and carbohydrate 82.30%. The anti-nutritional factors of the best blend were 8.21 mg HCNeqv/kg, 1.69 mg phytate/g and 0.37 mg tannin/g.

Growth performance of starter broiler chickens fed processed African yam bean meal as protein source in place of soyabean meal

Protein source like soyabean meal is expensive and constitutes about 15-30% of poultry and pig diets. Thus, the study was carried out to determine the growth performance of starter broiler chickens fed processed African yam bean meal as protein source in place of soyabean meal in their diets. The processed African yam bean meal (AYBM) was used to replace soyabean meal at various levels to determine the best level that would give optimal performance in starter broilers. The African yam bean seeds were procured at Ndioro market in Abia state and were sorted to remove stones and dirt by sieving. The seeds were soaked in water for 24 hours in large vats and then, the water was removed and the seeds were air dried for 3 days. The seeds were then toasted for 35 minutes in a frying pan, milled using hammer mill to obtain processed African yam bean meal, and then stored in bags until used. The proximate composition of processed African yam bean meal showed that it contained 8.29% moisture, 91.71% dry matter, 3.40% ash, 21.12% crude protein, 5.0% ether extract, 5.73% crude fibre and 56.46% nitrogen free extract. In the starter feeding trial, the processed African yam bean was used to replace soyabean meal at levels of 0, 10, 15, 20 and 25% respectively in the control diet. Each starter diet was fed to a group of 30 broiler chicks for 4 weeks using completely randomized design. Each treatment was divided into 3 replicates of 10 broiler chicks each. The broiler chicks were kept in pens in deep litter and given feed and water ad libitum. Parameters measured include; initial body weight, final body weight, body weight gain, feed intake, feed conversion ratio and cost of production. In the starter broiler feeding trial, the group on 10% processed AYBM compared favourably with the control (P>0.05) in terms of feed intake, feed conversion ratio and body weight gain. Cost of production per kg (was lowest for diet 2 (N463.38) against N471.63 for those on control diet. The result of the trial has shown that processed African Yam bean meal can be used to replace soyabean meal in the diet at 10% for optimum performance of starter broilers without affecting the body weight gain, feed intake and feed conversion ratio.

Biochemical and Histopathological Studies of Key Tissues in Healthy Male Wistar Rats Fed on African Yam Bean Seed and Tuber Meals

Food insecurity and malnutrition are currently major issues affecting most developing countries, especially on the African continent. To mitigate this effect, focus is being given to orphan or underutilized crops with immense potentials to boost food and nutrition security in Africa, such as the African yam bean (AYB) Sphenostylis stenocarpa. The effect of AYB seed and tuber meals on the tissues of the kidney, liver, and testis of healthy male Wistar rats were investigated in this study. Four accessions of AYB were used for this study, TSs 107, TSs 140, AYB 45, and AYB 57. Thirty rats were randomly assigned into five groups (n = 6). Group I was fed on standard pelletized rat chow (control), Group II fed on 50% seed meal, Group III fed on 100% seed meal, Group IV fed on 50% tuber meal, and Group-V fed on 100% tuber meal. At the end of the treatments, the animals were sacrificed after 72 h under light ether anesthesia, and biochemical and histopathological analyses were conducted on the tissues. Phytate concentration was higher in the seeds (TSs140 (550 mg 100g−1), AYB45 (460 mg 100g−1), and AYB57 (485 mg 100g−1)) compared to the tubers (TSs140 (14.8 mg 100g−1), AYB 45 (275 mg 100g−1), and AYB57 (240 mg 100g−1)). The consumption of 100% unprocessed AYB seeds caused liver and kidney damage in rats due to increased levels of aspartate aminotransferase (5.04 ± 1.62 U L−I), alanine aminotransferase (8.46 ± 2.43 U L−I), and lipid peroxidation (0.27 ± 0.02-unit mg−1protein). AYB tubers were innocuous to Wistar rats investigated. Good processing of AYB seeds is required for safe consumption by humans and livestock. This study has shown that tubers of AYB are safe for human consumption and should be utilized in meals as it contains fewer antinutrients and had no significant effect on the tissues examined in Wistar rats.

Updating the Data Base of Indigenous Raw Food Materials by Analyzing Their Chemical Compositions

Introduction: The porosity of recent data on the chemical compositions of indigenous food might contribute to poor food choices thereby promoting food and nutrition insecurity. This study provides data on the proximate, mineral and antinutrient compositions of raw, Triticum aestivum, Musa paradisiaca, Xanthosoma sagittifolium, Ipomea batata, Zea mays and Sphenostylis stenocarpa.
 Methodology: The raw food materials were purchased in Nigerian markets. Corn grains and African yam bean (AYB) seeds were sorted to remove impurities and separately milled into fine flours. Green matured plantain fruits, cocoyam, yellow and orange fleshed sweet potatoes tubers were separately washed to remove adhering soil particles, peeled and sliced into a thin thickness of about 2 cm and then dried in a food dehydrator (40- 50°C) for 24 hr. After drying, they were separately milled into fine flours. Chemical properties were analyzed using standard laboratory methods. Data generated were computed using means and standard deviations.
 Results: The ranges of the proximate compositions of the food materials were as follows: Moisture 4.3-11.8%, ash 0.6 -2.8%, dietary fibre 3.2-17.5%, fat 0.8-4.3%, protein 2.8 - 20% and available carbohydrate 48.5 -72.5%. The mineral contents of the samples were in the following ranges; iron 0.8-5.4 mg/100 g, zinc 0.51-2.43 mg/100 g, calcium 8-109 mg/100 g, potassium 135-325 mg/100 g, sodium 3-12 mg/100 g, phosphorus 84- 688 mg/100 g, magnesium trace -119 mg/100 g. The antinutrients were as follows: trypsin inhibitors 1.85 IU/mg, phytate ranged from 5.1-6.57 mg/g, oxalate 0.21-0.29 mg/g, saponins 0.03-0.02 mg/100 g, raffinose 0.88- 2.18%, stachyose 1.93 – 3.16%, lectins 32.5 Hu/100 g and tannins 0.9 mg/g.
 Conclusion: Knowing the nutrient contents of raw food materials will help food producers/processors and consumers combine foods leveraging on the comparative advantage of each nutrient to make up for limited nutrient(s). Also, knowledge of the antinutrient compositions of raw food staples will aid decisions on adequate processing methods to be employed in reducing or eliminating them.

Effect of Citric Acid Treatment and Fermentation on the Chemical Composition of African Yam Bean (Sphenostylis stenocarpa) and Sensory Evaluation of Its Gruel

Aims: Legumes, (especially indigenous/ underutilized legumes), have been found to make substantial contributions to nutrient intakes of the populace especially in low resources environments. The African yam bean (AYB) is one of such indigenous legumes with utilization constraints such as hard-to-cook phenomenon, beany flavour, bitter taste and some anti- nutritional factors that limit its utilization. The aims of this study were to determine effect of citric acid treatment and fermentation on the chemical composition of African yam bean (Sphenostylisstenocarpa) and sensory evaluation of its gruel.
 Methodology: Cream coloured AYB seeds were purchased in Enugu, Enugu State Nigeria. Sorted AYB seeds were washed and fermented in citric acid medium (0.25%, 0.5% and 1%) for 24 h 48 h and 72 h at room temperature (28°C) in a seed water ratio of 1:4 (w/v). The control seeds were fermented without citric acid for 24 h, 48 h and 72 h. After fermentation, each batch of the fermented seeds was divided into two. The first half was dehulled and the other half was left as whole. The fermented seeds were separately dried and milled into flour for further use. Standard methods were used for proximate, mineral and anti-nutrient analyses. Gruels were produced from all the flours and subjected to sensory evaluations using a nine-point hedonic scale. Data obtained were analyzed using a Statistical Package for Social Sciences (SPSS) version 20.0. The analysis of variance (ANOVA) was used to compute the mean and standard deviations. Means were compared using the least significant difference (LSD) and significance accepted at P<.05.
 Results: Chemical compositions of AYB flour fermented in 0.5% citric acid solution showed that protein contents increased by 50%, dietary fibre decreased by 0.02%. Raffinose, stachyose, lectins, trypsin inhibitors, tannins, oxalates, phytates and saponins were all significantly reduced to safe levels. Gruels made from raw and dehulled AYB seeds fermented for 24 h with 0.5% citric acid had higher scores for aroma (7.30 & 7.35, respectively) and general acceptability (7.32 & 7.22, respectively). Dehulled AYB fermented for 24 h in 1% citric acid had the highest score (7.99) for colour. Based on the sensory evaluation results, gruels made from the AYB seeds fermented in 0.5% citric acid compared with the gruels made from AYB seeds that were fermented in tap water. The results showed that gruels made from the AYB seeds that were fermented in 0.5% citric acid for 24 h had higher score for aroma (7.70), colour (7.10) and overall acceptability (7.52). Utilization of AYB in food formulation could be improved by fermenting in 0.5% citric acid solution for 24 h.

Chemical and Sensory Evaluation of African Yam Bean (Sphenostylis Sternocarpa) Seed-Enriched Cassava (Manihot esculenta) Product (Pupuru)

This study evaluated the proximate composition, total energy values and mineral profiles of Pupuru flour blends produced from fermented cassava ( Manihot esculenta Crantz) roots enriched with African yam bean ( Sphenostylis stenocarpa ) seeds (AYBS) and sensory qualities of stiff dough meals prepared from them. African yam bean seeds were cleaned, washed with and soaked in clean water for 24 h, manually dehulled, rinsed, cooked for about 45 min, rinsed, dried in an oven at 60 o C for 5 h, cooled to about 30 ± 2 o C, milled, sieved and added to cassava which was previously spontaneously-fermented for 96 h, toasted, cooled, milled, sieved and packaged to form Pupuru flour blends of various proportions (0:100 (P100), 5:95 (EP5), 10:90 (EP10) 15:85 (EP15) of AYB seed : cassava) and a commercial sample (CP) was used as a control. The proximate compositions indicated significant (p<0.05) reductions in moisture, fibre and carbohydrate but increased the protein, fat and ash contents and energy values of all the blends as enrichment levels with AYBS increased. Moisture (dry basis), protein, fat, fibre, ash, carbohydrate and total energy contents of the blends ranged from 6.78 - 9.26%, 3.18 - 21.74%, 2.18 – 4.98%, 2.79 - 3.57%, 2.91 – 3.93%, 59.78 - 80.26% and 364.02 - 387.20 Kcal, respectively. Mineral compositions were significantly (P<0.05) different: Sodium (143.00-187.00 mg/100g), Potassium (537.00-675.00 mg/100g), Calcium (129.30-201.50 mg/100g), Phosphorus (63.50-124.00 mg/100g), Magnesium (49.10-71.00 mg/100g), Copper (2.3-3.4 mg/100g), Manganese (1.20-21.20 mg/100g), Zinc (4.50-11.00 mg/100g), Iron (5.20-12.50 mg/100g) while lead was below detection level. All samples had good sensory scores and overall acceptability. Enrichment of Pupuru with AYBS, significantly (p<0.05) improved proximate and energy compositions, mineral profile, and sensory properties, hence, could be used to enhance food security and combat malnutrition in Africa. Keywords: Pupuru , Cassava, African yam bean ( Sphenostylis stenocarpa ) seed, Malnutrition, Food security DOI: 10.7176/FSQM/96-07 Publication date: April 30 th 2020

Effect of Plant Ash on Nutrient Quality and Antioxidant Activity of African Yam Bean Seed Porridge in Relation to Cooking Time

The present study aimed to investigate the nutrient quality, antioxidant activity and sensory acceptability of hard-to-cook African yam bean (AYB) seeds cooked for 5 h (control) and for 2 h with plant ash. The plant ash were unripe plantain peel ash (UPA), corn cob ash (CCA) and UPA and CCA mixture. Standard methods of Association of Official Analytical Chemists (AOAC) were used for the proximate and mineral analysis, DPPH, ABTS and FRAP assays were used to investigate the antioxidant activity. A completely randomized design with one way analysis of variance (ANOVA) was used for data analysis. The results showed that cooking of AYB seeds for 2 h with 8 g/100mL plant ash solution improved the nutrient contents, antioxidant activity and sensory scores of the porridge. Higher values of proteins, ash and energy were obtained in 8 g/100mL UPA/CCA and in 8 g/100mL CCA additives. However, moisture, fat and fibre contents were not affected by plant ash additives and were higher in 5 h cooked porridge. Cooking with 8 g/100mL plant ash solution for 2 h significantly increased mineral elements in the porridge. Phenolic compounds (total polyphenols and flavonoids), and antioxidant activity (DPPH, ABTS and FRAP) showed higher values with plant ash additives. This study reveals that addition of plant ash did not only reduce the cooking time of AYB seed by 60%, but also improved the nutrient quality, antioxidant activity and sensory acceptability.

EFFECTS OF STORAGE METHODS AND MYCOFLORA ON PROXIMATE COMPOSITION OF AFRICAN YAM BEAN (Sphenostylis stenocarpa Hochust ex Rich ) SEEDS

One of the limitations of African yam bean (AYB) (Sphenostylis sternocarpa) is poor storage ability due to the adverse effect of seed-borne fungi. This study was conducted to examine the effects of storage methods on nutritive composition of AYB seeds stored in three types of storage materials viz; jute bags, polypropylene bags and plastic bowls. Freshly harvested AYB seeds were stored in all the storage materials for 6 months using 2 × 3 factorial (2 AYB cultivars and 3 storage methods) in 3 replicates. The proximate analysis of the stored AYB seeds was carried out at 3 and 6 months after storage using standard methods. The temperature and relative humidity of the store room were recorded monthly. Seeds stored in jute bags gave the best values for crude protein (24.87%), ash (5.69%) and fat content (6.64%) but recorded least values for crude fibre (2.55%), carbohydrate (50.86%) and moisture content (12.68%) at the 6th month of storage. Temperature of the store room decreased from 32.9 ºC - 28.3ºC, while the relative humidity increased from 78% - 86%. Decreased incidence of field fungi namely: Rhizopus oryzae, Aspergillus flavus, Geotricum candidum, Aspergillus fumigatus and Mucor meihei was accompanied by increase in storage fungi viz: Apergillus niger, Mucor hiemalis, Penicillium espansum and Penicillium atrovenetum with prolonged storage. The study showed that out of the three storage materials, jute bag was more effective in preserving AYB seeds.

Pasting Properties of Flour Blends from Water Yam, Yellow Maize and African Yam Bean Seeds

Pasting properties of flour blends from water yam, yellow maize and African yam bean were investigated in this study. Peak viscosity ranged from 133.50 to 166.25RVU, Trough viscosity ranged from 85.08 to 135.20RVU, break down viscosity ranged from 28.17 to 50.58RVU, final viscosity ranged from 5.05 to 5.49 min and pasting temperature ranged from 80.25 84.15oC. Addition of yellow maize and African yam bean affected (p<0.05) the peak viscosity, trough viscosity, break down viscosity, final viscosity, and setback viscosity in different trends. However, peak time and peak temperature of the flour sample were not statically (p<0.05) affected by the blend ratio in this study. Amongst the flour samples investigated in this study, flour sample DIN (60%WY:10%YM:30%AYB) showed promise for value added products such as noodles among other flour products. They flour sample adjusted to be the best sample could be used as a good replacement for wheat flour and when achieved, it will reduce the cost of importation.

Proximate, mineral and anti-nutritional compositions of raw and processed African Yambean (<i>Sphenostylis stenocarpa</i>) seeds in Cross River State, Nigeria

African yambean (Sphenostylis stenocarpa, Hochst. Ex A. Rich, Harms) is an indigenous legume in tropical Africa. This food crop legume is highly under-exploited and very little scientific information is available in literature. In this study, the chemical composition (proximate, minerals and anti-nutritional profile) of raw and processed African yambean (AYB) seeds was investigated. Seeds of brown seed coat landraces of African yambean were collected from various locations in the Northern part of Cross River State. The seed characteristics were noted and subjected to boiling and toasting for one hour and thereafter evaluated for proximate composition, gross energy, mineral and antinutritional properties. Results showed that boiling significantly (P<0.05) increased crude Protein (CP) (22.10%), ether extract (EE) (7.53%) and gross energy (GE) (5.23 Kcal/g) compared to the raw (21.61% CP, 5.12% EE and 4.88 Kcal/g GE) as well as toasted seeds (21.41% CP, 5.195 EE and 4.51 Kcal/g GE). Toasting significantly (P<0.05) increased nitrogen free extract (NFE) (50.65%) and ash values. Processing (boiling/toasting) had significant (P<0.05) effect on mineral composition (Ca, Mg, K, Na and Fe) of the seeds except for phosphorus. Boiling significantly (P<0.05) reduced phytate (0.68%), alkaloid (0.70%) and trypsin-inhibitor (0.08 IU/mg) contents. Results have shown that African yambean seeds are rich sources of nutrients but have low human preference for food. But have a high potential as an energy/protein source in livestock feeds. The boiled AYB seeds had highest CP, mineral and lowest in anti-nutrient contents. Hence, boiling was the preferred processing method for AYB seeds.Keywords: Boiling, legume, nutrient profile, toasting, yambean