Water Yam Flour Research Articles

SENSORY EVALUATION AND ACCEPTABILITY OF WATER YAM (DIOSCOREA ALATA) FLOUR FOR PRODUCTION SNACKS

This study assess the acceptability of processed water yam flour as a snack and its sensory evaluation. Using water yam flour and wheat flour in the ratios of 70:30 and 50:50, two distinct composite flour blends were created. As a control, there were samples made of wheat flour. The purpose of the study was to investigate the potential applications of Nigeria's freely obtainable water yam flour for making chinchin, cake, and cookies. In order to accomplish this, chinchin, cakes, and cookies made with water yam and wheat flour were prepared and then subjected to sensory analysis. Based on its appearance, color, flavor, texture, taste, mouth feel, crispiness, and overall acceptability, food products such chinchin, cake, and cookies were utilized to assess the sensory acceptability. For sensory evaluation, an 8-point hedonic scale was employed. The mean separation was performed using the Duncan New Multiple Range Test. The data was analyzed using the mean(x) score, simple percentage, standard deviation (SD), and analysis of variance (ANOVA). To clarify how new recipe is created, the study used an experimental research approach. It was evident from the findings that the judges accepted chinchin, cakes, and cookie sampling. The study concluded that, with regard to the factors examined, there was no discernible variation in the judges' ratings. Based on the results, the researcher concluded that water yam flour can be used in place of wheat flour and that products like chinchin, cakes, and cookies made with water yam flour should be encouraged by the producers.

Quality evaluation of therapeutic noodle from water yam, millet and wheat composite flour and its effect on lipid profile and blood glucose concentration using albino rats

This study investigated the development and sensory qualities of therapeutic noodle from wheat, pearl millet (Pennisetum glaucum) and water yam composite flour and the effect of feeding the product on lipid profile and blood glucose concentration using alloxan induced albino rats. The therapeutic noodle was produced using different ratios of flour blends of wheat, millet and water yam. Sensory analysis was carried out based on color, taste, aroma, slipperiness and overall acceptability on the basis of a 9-point hedonic scale. The therapeutic noodle samples competed well with the commercial noodle (control) sample as they were all rated above average (>5.0) with noodle sample (WMF5) having a very high score of 8.40 in the overall acceptability. Alloxan induced male albino rats were fed the formulated therapeutic noodle for 21 days and assessed for their resultant body weight, blood glucose concentration and lipid profiles. The total cholesterol levels of all diabetic albino rats fed the formulated therapeutic noodle were reduced to within the normal range of below 200mg/dl ideal for adults after the 21days. The therapeutic noodles also helped to significantly (p < 0.05) reduce the high blood glucose concentration of the diabetic rats to below 200mg/dl while diabetic rats fed control diet (100:0) had the highest concentration of blood glucose (485mg/dl). Due to the high anti-diabetic properties of the therapeutic noodles, it can be recommended as a functional food source for the treatment of overweight, obesity, and diabetes.

Engineering Parameters Responses during Extrusion Processing of Noodles Analogue from Water Yam, Yellow Maize, and African Yam Bean Flour Mixture

This study investigated the effect of extrusion process on engineering properties of noodles analogue from water yam, yellow maize, and African yam bean. Flour blend from water yam, yellow maize, and African yam bean were produced using the standard method of dry milling and was used to extrude noodles analogue using a brabender single screw laboratory extruder (Duisburg DCE 330 model) fitted with 3.0mmdie nozzle diameter. A central composite rotatable design (CCRD) with three variables, namely barrel temperature, feed moisture content and screw speed and five level coded – a, -1, 0, +1,, +a, was used for the study and data was generated at (p<0.05). Results of result of the engineering properties of noodles analogue showed that toque ranged from 22.4 to 60.50Nm/s, mass flow rate ranged from 33.90 to 109g/min-1, specific mechanical energy ranged from 100.19 to 385.97kj/kg, and the residence time ranged from 22 to 55s in this study. The CCRD was effective in explaining the effect of the process conditions on noodles analogue as influenced by barrel temperature, feed moisture content, and screw speed of the extruder. The data obtained from the study could be used for control of product characteristics.It was generally observed that the changing of feed moisture content, barrel temperature, and screw speed influenced an acceptable torque, mass flow rate, and residence time during the extruder operation. The noodles analogue produced at this cheap machine operating conditions could be projected for commercial production.

Effect of Extrusion Process on Proximate Composition of Water Yam Based Noodles Analogue – A Response Surface Analysis

Response surface methodology was used to investigate the effect of extrusion process on proximate composition of noodles analogue from water yam, yellow maize, and African yam bean flour mixture. Flour blend from water yam, yellow maize, and African yam bean were produced and was used to extrude noodles analogue using a brabender single screw laboratory extruder (Duisburg DCE 330 model) fitted with 3.0mm die nozzle diameter. A central composite rotatable design with three variables, namely barrel temperature, feed moisture content and screw speed and five level coded – a, -1, 0, +1,, +a, was used and data analyzed by regression analysis. Results showed that proteins of noodles analogue ranged from 12.40 to 22.16%; fat content ranged from 2.98 to 6.07%; fibre content ranged from 1.80 to 2.52%; ash content ranged from 6.21 to 9.50%; moisture content ranged from 11.05 to 12.47% and carbohydrate content ranged from 48.31% to 63.65% respectively. The coefficients of determinations (R2) were high and ranged from 0.9106 to 0.9747 at 5% level. The response surface plot suggested that the models developed had a good fit and the CCRD was effective in explaining the effect of the process conditions on noodles analogue as influenced by barrel temperature, feed moisture content, and screw speed of the extruder. The data obtained from the study could be used for control of product characteristics. The study indicated that improved noodles analogue produced from available and cheap roots, cereal and legumes such as water yam, yellow maize, and African yam bean can be produced for possible projection for the commercial production of noodles analogue.

Functional Properties of Noodles Analogue from Water Yam, Yellow Maize, and African Yam Bean Mixtures – A Response Surface Methodology

Response surface methodology was used to investigate the effect of extrusion process on proximate composition of noodles analogue from water yam, yellow maize, and African yam bean flour mixture. Flour blend from water yam, yellow maize, and African yam bean were produced and was used to extrude noodles analogue using a Brabender single screw laboratory extruder (Duisburg DCE 330 model) fitted with 3.0 mm die nozzle diameter. A central composite rotatable design (CCRD) with three variables, namely barrel temperature, feed moisture content and screw speed and five level coded – a, -1, 0, +1, +a, was used and data analyzed by regression analysis. Results showed that bulk density ranged from 0.41 to 0.09 g/cm water solubility index ranged from 4.41 to 6.36%; water absorption capacity ranged from 2.05 to 5.66% and expansion ratio ranged from 1.62 to 3.81respectively. The coefficients of determinations (R2) were high and ranged from 0.9039 to 0.9887 at 5% level. The response surface plots suggested that the models developed had a good fit and the CCRD was effective in explaining the effect of the process conditions on noodles analogue as influenced by barrel temperature, feed moisture content, and screw speed of the extruder. The data obtained from the study could be used for control of product characteristics. The study indicated that improved noodles analogue from available and cheap roots, cereal and legumes such as water yam, yellow maize, and African yam bean can be produced for possible projection for the commercial production of noodles analogue.

PROXIMATE COMPOSITION AND SENSORY EVALUATION OF CAKE PRODUCED FROM WATER YAM (DIOSCOREA ALATA) A PANACEA FOR SURVIVAL AFTER RETIREMENT IN NIGERIA

Cake is a staple food product which has gained acceptance among consumer in the world today especially in Nigeria. Considering the present economic crises and recession with late payment of retirees in Nigeria, finding the alternative to the imported and very expensive wheat for survival after retirement will not be a bad idea. The study was carried out to examine the possibility of the use of water yam flour that grows easily in Nigeria for the production of cake for a maximum profit in Nigeria. This was done by analyzing the proximate composition and sensory evaluation of cake produced from water yam flour. The sample was subjected to sensory evaluation on colour, texture, taste, flavor and general acceptability a nine point hedonic scale was used. Twenty panelists were used for the sensory evaluation. Data was analyzed using mean and analysis of variation (ANOVA). Six code samples at 100% water yam flour, 100% wheat flour, 80%, 20%, 70%, 30%, 60%, 40%, 50%, 50% of water yam flour and wheat flour respectively. The instrument used was Sensory Evaluation Score Sheet (SESS) filled by the panelists during the testing session. They were evaluated for colour, taste, flavor, texture and general acceptability. Results obtained showed that cake and biscuits samples had majority of the respondents/subjects like slightly (LS) on the ground of taste, colour, flavor, texture and acceptability were accepted except for the case of texture of physical properties of cake to which they indicated neither like nor dislike (NLND). Proximate analysis was determined by food analysis (moisture, crude protein, ash, crude fibre and carbohydrate). Based on these findings, it was concluded that cake produced from water yam flour and wheat flour be recommended for food and pastries manufacturing companies for production and marketing. It is recommended that cake from water yam and wheat flour should be taken because it improves the nutritional value of confectionaries.

QUALITY EVALUATION OF SHORTBREAD BISCUITS PRODUCED FROM WATER YAM-WHEAT FLOUR BLENDS

Water yam is a tuber crop that is valued for its nutrient composition amongst other yam cultivars. This study investigated the quality of shortbread biscuits produced from water yam and wheat flour blends. Shortbread biscuits were produced from seven formulations of composite flours made from wheat and two varieties of water yam (purple and white) at 30%, 50% and 60% ratios. Shortbread biscuits produced from 100% wheat flour served as control. The functional properties of the composite flours as well as the proximate composition, physical and sensory properties of the shortbread biscuits produced were determined. The functional properties of the flour blends such as oil absorption capacity, water absorption capacity, foam stability, gelatinization temperature and gelatinization time significantly (p˂0.05) increased with increase in the incorporation of water yam flours. Foam capacity, emulsion capacity and wettability recorded highest for the control sample. Bulk density showed no significant difference (p˃0.05) among all the flour blends. Shortbread biscuits differed significantly (p˂0.05) in the proximate composition with the moisture content, crude protein, ash, carbohydrate and energy with the incorporation of water yam flours. The control recorded the highest values for crude fat (14.03%) and crude fiber (1.25%). The physical properties of the shortbread biscuits varied significantly (p˂0.05) in terms of weight, thickness, height and breaking strength. The result of the sensory properties revealed a high general acceptability for all the shortbread biscuit samples. The result of this study deduced that up to 30% water yam substitution can be used for baked food products.

Effect of cocoyam and water yam flour blends on the chemical and mineral composition of dry soup mix

The effect of cocoyam and water yam flour blends on the chemical and mineral composition of dry soup mix was studied using a two-factor simple lattice design of response surface methodology (RSM). The cocoyam and water yam flour mix ratios are 100:0, 0:100, 50:50, 75:25, and 25:75. Moisture, protein, ash, crude fiber, fat, carbohydrate, amylose, amylopectin, calcium, magnesium, and phosphorus were all taken into consideration during the optimization process. On crude fiber, fat content, carbohydrate, calcium, and phosphorus, the linear influence of cocoyam and water yam flour was significant (p<0.05). Moisture, protein, ash, crude fiber, fat, amylose, amylopectin, and magnesium all exhibited a significant (p<0.05) effect on the mix's binary regression coefficient. The binary effect of the blend, on the other hand, decreased the moisture content and crude fiber significantly (p<0.05). On two component mix plots, the blends' linear and binary impacts were graphically depicted. The resulting models were validated at a significance level of 0.05. Furthermore, a desirability of 0.493 was chosen for outcome optimization. The optimization criteria were met by the response variables. The optimal values were: 69.84 g cocoyam, 30.15 g water yam, 5.84% moisture, 11.04% protein, 3.69% ash, 2.18% crude fiber, 2.00% fat, 75.34% carbohydrate, 24.77% amylose, 84.24% amylopectin, 9.17% calcium, 4.71% magnesium, and 79.83% phosphorus. The optimized values were further analyzed to ascertain 95% confidence. According to the findings, cocoyam and water yam flour blends with appropriate chemical and mineral composition can be created and used successfully in the food processing industry

Quality Evaluation and Kinetics of Dependency of Apparent Viscosity of Whole Wheat- Water Yam Flour Mixture on Temperature in Relation to The Cooked Paste

In the past, cooked paste commonly called fu-fu from whole wheat flour was well acceptable by African indigenes due to its light weight, fibre composition and other nutrients. However, it is a carbohydrate rich food and contains gluten not acceptable by some individuals’ body systems. Quality evaluation and kinetics of dependency of apparent viscosity of whole wheat-water yam flour mixture on temperature in relation to the cooked paste were investigated. Composite flours (80:20-B, 60:40-C, 50:50-D, 40:60-E, 20:80-F; WYF: WMF-whole wheat meal flours) were formulated from wheat grains and water yam tubers. Samples A (water yam flour (WYF-100%)) and G-commercial whole wheat meal flour (WWF-100%) served as control. Flour samples were subjected to proximate, selected micronutrient, viscous and pasting characteristics analyses, while the cooked paste was evaluated using selected sensory attributes. Crude fat content of flours ranged from 0.19-1.80%, while crude fibre content differed significantly (p< 0.05) and varied between 1.08 and 4.88%. Crude protein content ranged from 2.10-4.50%, while carbohydrate by difference ranged from 61.10-80.10%. Heating temperatures for the flour dispersions ranged from 70-100oC. Sample B had the highest final viscosity among the blended samples. Apparent viscosities of the dispersions increased with increasing temperatures and displayed dilatants fluid behaviour. Sample B had the lowest value of activation energy required to obtain a suitable cooked paste among others. Overall results indicated that sample B could be consumed as an alternative cooked fu-fu to whole wheat flour fu-fu.

Modeling of thin layer drying characteristics of blanch-assisted water yam (Dioscorea alata) slices

The thin layer drying characteristics of blanch-assisted water yam slices were investigated with respect to its un-blanched water yam slices in a convective hot air oven. The yam slices (diameter 4 cm; thickness 0.8 cm) were dried at temperatures 50, 60 and 70 °C, respectively with a constant air velocity of 0.13 m/s. The drying data obtained were fitted into six existing drying models: Page, Newton, Midilli, Henderson and Pabis, Logarithmic and Diffusion model. Non-linear regression analysis was used to determine the model parameters; the coefficient of determination (R2) and standard error of estimates (SEE) in order to determine the model best fit. The study showed that the drying process occurred in the falling rate drying period. The blanch-assisted slices had a faster drying rate than the un-blanched yam slices. Among the models, the diffusion model gave the overall best fit for the drying data obtained. The effective moisture diffusivity ranged from 3.18×10-8 to 4.47×10-8 m2/s for the blanch-assisted slices and from 4.73×10-8 to 7.33×10-8 m2/s for the un-blanched slices. The activation energies of the blanch-assisted and un-blanched yam slices were 15.5 kJ/mol and 20.1 kJ/mol, respectively. These processing conditions obtained for water yam flour would be suitable for its process design and control thereby enhancing its utilization and overall acceptability.

PHYSICOCHEMICAL PROPERTIES OF FLOUR AND STARCH OF PURPLE WATER YAM (Dioscorea alata) TUBER AND THE DIFFERENCE ON SENSORY ACCEPTANCE OF THE COOKIES PRODUCED

Purple water yam tubers (PWYTs) or Dioscorea alata are edible tubers containing bioactive compounds that are beneficial to human health. Its high carbohydrate content can be used to make flour or starch to increase its shelf life and food diversification. However, this food is unpopular among several communities in Indonesia, particularly for the juveniles due to limited processing knowledge. Therefore, this study aims to characterize the physicochemical properties of purple water yam flour (PWYTF) and starch (PWYTS) in order to assess consumers' acceptability toward gluten-free cookies. The PWYTF was prepared by drying peeled tubers, which was subsequently grounded. Meanwhile, the PWYTS was prepared by homogenizing the peeled tubers with water, the sediment from supernatant was dried. The chemical properties, such as moisture, ash, fiber, protein, and lipid, were determined using the Indonesian national standard procedures for flour. The physical properties, namely pH, bulk density (BD), water/oil absorption capacity (W/OAC), water/oil binding capacity (W/OBC), swelling power (SP) and solubility (Sol) were evaluated. The PWYTF and the PWYTS were used to make gluten-free cookies, with their physical properties and consumer's acceptability evaluated using semi-trained panelists. Yields of both the PWYTF and the PWYTS were 36.10% and 26.63%, respectively. The chemical compositions of the PWYTF and the PWYTS were significantly different (p0.05) for carbohydrate (80.34 and 80.78 %), crude protein (0.78 and 0.81%), and crude fiber (2.0 and 1.9%) except for the ash content (2.6 and 0.5%), lipid (0.3 and 0.1%), and moisture (13.77 and 15.70%). Furthermore, their physical properties were also significantly different (p0.05) for pH (6.62 and 5.84), BD (0.46 and 0.68 g/mL), WAC (2.07 and 0.46 g/g), WBC (1.07 and 0.49 g/g), SP, and Sol except OAC (1.63 and 1.49 g/g) and OBC (0.63 and 0.49 g/g). The cookies made from the PWYTS were appreciated with the highest hardness and rated from panelists. Therefore, the PWYTS can be used in place of a commercial wheat flour to make cookies..

Functional Properties of Purple Water Yam Flour Modified by Lactobacillus plantarum

Purple water yam flour modified by Lactobacillus plantarum fermentation may be used as an ingredient in flour-based functional food. The purpose of this research is to determine the effect of fermentation time on the functional properties of purple water yam flour modified using L. plantarum. This research used a randomized block design with six treatments: without fermentation (control) and 12, 24, 36, 48, and 60 h of fermentation. Results showed that lactic acid bacteria initially grow well with increasing viability over 48 h of fermentation. Growth and viability rates began to decrease as the organisms entered the declining or dying phase. Statistical analysis showed that fermentation time affects the solubility at 75 °C, chromatic color values L* and b*, and antioxidant activity of flour. Fermentation for 36 h produced the best modified purple water yam flour with an antioxidant activity of 69.82%, bulk density of 0.817 g/mL, water absorption capacity of 3.31 g/g, oil absorption capacity of 1.20 g/g, solubility of 0.45%, L* of 80.33, a* of 16.33, and b* of −5.33. The results indicate that purple water yam flour modified by L. plantarum fermentation for 36 h could be developed as a functional food ingredient.

PREFERENSI KONSUMEN TERHADAP ORGANOLEPTIK COOKIES NON TERIGU (CONSUMER PREFERENCE TO COOKIES GLUTEN FREE’S ORGANOLEPTIC)

Cookies is a popular snack in the world made from wheat flour. Level of wheat flour consumption in Indonesian in 2015 was 1,552 per capita.In other side, cookies gluten free as well as water yam flour, maizena flour, bekatul, mocaf, suweg, and rice flour is developing to replace wheat flour despite of less popular. The research was aim to identificate consumer preference of cookies gluten free’s organoleptic. Research design used complete randomized design (RAL)which the varians of rice flour, tapioca flour, and maizena flour. Organoleptic test used to identificate level of consumer preference. Result of the research showed that level of consumer preference to the varians of rice flour, tapioca flour, and maizena flour has no significantly different (p=0,008). 10 from 27 consumer prefered cookies 412 which all the atribut texture, colour, and flavour. Conclusion : Cookies 412 was the best cookies than others followed by its texture atribut.

Effect of Gum Arabic Incorporation on the Proximate Composition and Sensory Properties of Biscuits Produced from Flour Blends of Wheat and Water Yam

The aim of this study was to evaluate the influence gum Arabic incorporation on the proximate composition and sensory properties of biscuits produced from flour blends of wheat and water yam. Water yam was processed into flour and used in composite with wheat flour for biscuit production. Two formulations A and B were produced from the mixture of wheat and water yam flour in the ratios of 50:50 and 30:70, respectively. The two formulations each were used to produce biscuits with different concentrations of gum Arabic (0%, 0.3% and 0.5%) and 100% wheat flour as control. Biscuit samples were subjected to proximate and sensory analysis using standard methods. Increase in the concentration of gum Arabic resulted to an increase in the moisture content (5.63-6.41% and 5.31-6.01%), crude fibre (1.13-1.95% and 2.22-3.40%) and carbohydrate contents (76.96-78.99% and 73.73-77.75%) for formulations A and B, respectively. A decrease in the ash content (3.11-2.85% and 4.60-2.78%), fat (5.35-2.56% and 5.62-2.51%) and protein content (7.82-7.24% and 8.52-8.05%) was also observed as the concentration of gum Arabic increased for formulations A and B, respectively. Result of the sensory analysis revealed that the control biscuit sample was more preferable for colour, taste, flavor, softness and general acceptability while biscuit samples containing 0.5% gum Arabic was more preferred for crispiness and hardness. The result also showed that the incorporation of gum Arabic led to increased sensorial attributes of wheat/water yam composite biscuits. The control sample and biscuit sample containing 30% water yam flour, 70% wheat flour and 0.5% gum Arabic were significantly similar for crispiness, hardness, softness and overall acceptability suggesting that gum Arabic can be incorporated at 0.5% into wheat and water yam composite flour at 70% and 30%, respectively for the production of acceptable and quality biscuits.

The Characteristics of Crackers Made from Formulation of Wheat and Modified Water Yam Flour

The previous study showed that combination of wheat flour (70%) and modified water yam flour (30%) produced crackers which had the best characteristics. In this research, the effect of formulation of wheat and three kind of modified water yam flour on Resistant Starch (RS) content and Glycaemic index of the crackers were studied. Modified water yam flour was made from purple, white, and yellow ones which had been treated by three cycles autoclaving-cooling process. The native water yam flour, without treatment with autoclaving, were used as comparison. The result showed that sample crackers had higher resistant starch (1.67 -3.65%) and dietary fiber (16.65 -18.41%) content, compared to standard crackers from wheat flour. Furthermore, the crackers from modified yam flour with white water had the lowest GI (34.13) comparing with other crackers. So it could be developed as functional food for preventing diabetes mellitus or other digestive tract disrupter.

Physico-Chemical Properties of Water Yam and Cowpea Flour Blends for Production of Snacks

Aim: The aim of this study is to produce flour from different blend ratio of water yam and cowpea and determination of the physico chemical properties of the snacks produced from the flour blends.
 Introduction: Snacks are something consumed occasionally for pleasure rather than for nutritive purpose. They are mainly produced by wheat flour. Wheat flour, the main ingredient for production of snacks are imported and thus, the cost of importation of wheat flour eat deep into the Nigeria economy and has placed a considerable burden on the foreign exchange reserve, in the long run causes increase in wheat products. Furthermore, over consumption of wheat products leads to celiac disease associated with immunological disease of the upper intestine triggered by the ingestion of gluten containing cereals. Production of alternative flour to wheat flour can be a welcome idea. Cereal has high nutritional value and it has an appreciable protein content.
 Study Design: The physico chemical analysis was carried out at the biochemistry laboratory of National Root Crop Research Institute Umudike.
 Methodology: The water yam (Dioscorea alata) and cowpea (Vigna unguiculata) flours were prepared and they were used for water yam/ cowpea blend at different ratio of (ie 100%:0, 90:10, 80:20, 70:30, 60:40 and 50:50). The 100% water yam was the control sample. Functional properties and proximate composition of the samples were determined.
 Results and Discussion: According to the result generated from the sensory evaluation, it was discovered that yam/ cowpea blend in the ration of 50:50, 60:40 and 70:30 were more acceptable than the other samples. This can be related to the high content of cowpea in the samples.
 Conclusion: The yam /cowpea blend in the concentration of 50; 50 was more preferred than the other samples by the panelist. As a means of nutritional balance yam fortified with cowpea can boost the protein intake of population consuming yam as its main staple.

Improved Yam-Baobab-Tamarind flour blends: Its potential use in extrusion cooking

This project was aimed at determining the physicochemical properties of water yam-baobab-tamarind flour composites and its potential use in extrusion cooking. Proximate and mineral composition of Baobab (B), Yam (Y), and Tamarind (T) were determined. Six blends of composite flours were formulated and colour and physicochemical properties were determined. Two of the flour blends were used as trial samples and extruded. Proximate composition of B, Y and T were comparable to similar literature reports, however, the mineral compositions were low. Moisture content, pH, water binding capacity, swelling power and bulk density values ranged from 3.01-5.61%, 3.90–5.39, 87.50–132.50%, 201.43–237.95% and 0.74–0.93 g/mL, respectively, for the flour blends. Peak, minimum, cooling end, final, breakdown and setback viscosities were in the range of 2.50–291.00bu, 2.20–289.50bu, 11.00- 455.00bu, 10–440bu, 0.00–20.50bu and 69.50–148.00bu, respectively, for flour blends. The addition of tamarind and baobab flours improved the swelling power, water binding capacity and peak viscosity of flour extrudates. Generally the L, a, and b values for extrudates were lower than the flour composites. However, the panelist preferred the appearance. The bulk density and expansion ratio of extruded snacks were low. Generally, panellists preferred extrudates with higher (40%) tamarind kernel powder substitution (E5). The extruded composite flour (E6) had low viscosity values. Incorporation of tamarind and baobab into water yam flour has great potential for development of extruded snacks.

Quality Assessment of Bread from Wheat, Water Yam and Soybean Flours

The physicochemical and sensory evaluation of bread from the composite of wheat, water yam and soybean flours were determined. Five bread samples were produced from the proportion of wheat/water yam/soybean flours as 80%:10%:10% (B), 75%:15%:10% (C), 70%:20%:10% (D), 65%:25%10% (E) and 100% wheat was the control sample (A). The moisture, crude protein, fiber and ash increased (p≤0.05) significantly while the carbohydrate and fat content decreased (p≤0.05) significantly with corresponding increase in the percentage of the composite flour from 10-25% for water yam flour at constant 10% soybean level. The result of the physical properties showed that there was a significant difference in all the physical parameters except loaf weight which didn’t increased (p≥0.05) significantly with increased addition of water yam flour at constant soybean level. The result of the sensory analysis showed there were significant differences in all the sensory scores. However, consumers preferred the bread from the composite flours of 20% substitution for both water yam and soybean flours.

Effects of carbon sources on pigment production by <i>Talaromyces purpurogenus</i> LC128689 in liquid surface cultures

A pigment producing fungus was isolated from soil collected from cassava processing site in Ebonyi State. The effects of carbon sources on pigment production by the isolate in liquid surface cultures were studied. Pigment production in a basal medium composed of (in g/L) MgSO4, 0.4; NaNO3, 0.8; peptone, 15 mixed with 12g/L of one of the following carbon sources: glucose, Ipomea batatas, Dioscorea alata, Manihot esculenta cratz, Colocasia esculenta flour or soluble starch, was investigated. The highest red, orange and yellow pigment concentrations were obtained with sweet potato and water yam flour, followed by soluble starch while the least pigment concentrations were obtained with glucose. Unit optical densities of red (13), orange (9.5) and yellow (11) pigments were produced by the fungus using Ipomea batatas flour. These were higher than the concentrations of red (9), orange (7) and yellow (10.5) produced from Hajjaj medium composed of (in g/L) Glucose, 50; monosodium glutamate, 12; K2HPO4, 2.5; KH2PO4, 2.5; MgSO4, 1; KCl, 0.5; ZnSO4, 0.001; FeSO4, 0.001; and MnSO4, 0.001. The results indicate that Ipomea batatas flour is a better carbon source than glucose for pigment production by T. purpurogenus and thus has a very high potential for commercial production of pigments.Keywords: Microbial pigments, natural colourants, carbon sources, sweet potato, T. purpurogenus

Food Processing Characteristics of Water Yam (Dioscorea alata) and Cowpea (Vigna unguiculata) Flour Blend Used Locally for Production of Concessionaries

The performance of blends of water yam (Dioscorea alata) and cowpea (Vigna unguiculata) flours for preparation confectionaries was investigated. Water yam and cowpea were processed into flours and 100% water yam flour served as the control sample. However, water yam cake, chinchi and bread were produced using water yam flour and cowpea flour which were blended at different ratio (ie. 100%:0, 90:10, 80:20, 70:30, 60:40 and 50:50). The proximate analysis and functional properties of the water yam-cowpea flour were determined. The sensory evaluation showed that samples 50:50, 60:40 and 70:30 were the most acceptable because they contained little quantity of cowpea flour. The scores obtained for overall acceptability of the confectionaries ranged from extremely dislike to extremely like, indicating that the cake samples were generally liked by the panelists. This study showed that the panelists like the sample 50:50 more than the other samples. Therefore, the cowpea fortified yam flour could contribute to quality protein intake in populations consuming yam as a staple, due to its indispensible amino acid content.