Fat reduction affects quality of akara (fried cowpea paste)

Akara, a fried finger food made from cowpeas (Vigna unguiculata), is popular in West Africa and has been shown to be acceptable to American consumers. Akara is, however, a high‐fat food (about 31%, dry wt basis). We determined the effects of incorporating two modifiers, high amylose cornstarch or extruded cowpea flour, on akara fat content and consumer acceptability. The modifiers were used at the 10% level. Akara fat content was reduced by 26.1% with cornstarch and by 36.8% with extruded cowpea flour. There were no significant differences in sensory ratings among samples, and all samples received acceptable ratings (6 = like slightly) for overall liking.     

Effect of saponins on the foam/flow properties of paste and physical characteristics of akara made from decorticated black‐eyed cowpeas

Akara, a deep‐fat‐fried cowpea paste product, is a popular snack food in West Africa. Foaming capacity of the cowpea paste is important for achieving a spongy light‐textured fried product. The effect of two saponins, Yucca and Quillaja, on the foaming capacity of cowpea paste was investigated. Results showed that an increase in the amount of saponin added (1, 2, 4%) resulted in a decrease in specific gravity and apparent viscosity of the cowpea paste. Addition of saponin also significantly reduced the firmness and increased the cohesiveness of the akara compared with the control. Akara made using the Quillaja saponin was less firm and more cohesive than akara made using the Yucca saponin. An increase in the amount of saponin added to the cowpea paste resulted in a darker (lower L*) and browner colour of akara. However, akara containing 1% Yucca saponin had similar colour attributes to the control but was less firm and more cohesive. Copyright © 2005 Society of Chemical Industry     

Sensory properties of akara (fried cowpea paste) prepared from paste stored at low storage temperatures

Akara (fried cowpea paste) a popular West African cowpea (Visna unguiculata) product was prepared from cowpea paste stored under refrigeration (4‐6°C) and freezer (‐18°C) temperatures for 10 and 24 days respectively. Blanched and unblanched paste were stored. Akara from freshly prepared paste was used as control. The sensory properties investigated were colour, taste, texture and aroma. Akara from various paste samples; refrigerator stored paste (RSP) freezer stored paste (FSP) and fresh paste (FP) were rated for the various attributes and the degree of difference from the control by a trained panel. Sensory attributes of RSP akara were majorly rated between good and fair in the first 3 days. Attributes were rated between fair and bad by the 6^th and 10^th days of storage and were significantly different from FP akara. Sensory attributes of FSP akara were rated between good and fair until the 17^th day of storage. Blanching proved beneficial as a pre‐storage treatment for the preservation of akara texture in the first 3 days for RSP and for 24 days for FSP. The results showed that the properties of cowpea paste which influence texture and overall sensory quality of akara, were better preserved in frozen storage. The implications of the results on the feasibility of bulk production and storage of cowpea paste for retail as a frozen ingredient are discussed.     

BAKING PERFORMANCE AND CONSUMER ACCEPTABILITY OF RAW AND EXTRUDED COWPEA FLOUR BREADS

Cowpea flour was used to partially replace wheat flour in yeast bread, using automatic household‐type bread machines for mixing, proofing and baking. Loaves containing 15 or 30% extruded cowpea flour weighed more (683.4 g) than loaves from other treatments (641.1–652.6 g). The 100% wheat had the highest loaf volume (2.58 L) and the 30% extruded cowpea the lowest (1.64 L). Cowpea flour breads contained more protein (13.9–15.4%) than the 100% wheat (4.1% fat, 12.5% protein). Bread made with 15% extruded cowpea flour was not different (P < 0.05) from the all‐wheat control in sensory quality and acceptability. Hedonic ratings for the control and 15% extruded cowpea flour ranged from 6.6 (like slightly) to 7.4 (like moderately) for all sensory attributes. The least liked samples contained either 30% raw or 30% extruded cowpea flour, receiving ratings for all attributes ranging from 4.8 (disliked slightly) to 6.2 (liked slightly). Overall, 15% extruded cowpea flour demonstrated successful bread making performance without compromising sensory quality.     

EFFECT OF FROZEN STORAGE ON THE QUALITY OF AKARA, FRIED COWPEA (VIGNA UNGUICULATA) PASTE

Akara, a fried food of West African origin, is made from whipped cowpea paste flavored with fresh onion, fresh hot or bell pepper, and salt. Akara has potential for U.S. markets as a fully cooked, frozen, reheatable product. Akara was stored at ?18°C for 9 months and compared to freshly prepared akara in selected quality characteristics. Frozen, thawed akara had a higher moisture and lower crude fat content, required significantly less force to shear, and had a lighter, less intense color than freshly prepared product. Frozen/thawed/reheated akara received lower senson scores for color, moistness and flavor than the fresh product. Analysis of headspace volatiles of freshly prepared akara and akara frozen 3, 6 and 9 months resulted in fifteen peaks. Two peaks were significantly affected by frozen storage.     

EDIBLE COATINGS FOR REDUCING OIL UPTAKE IN PRODUCTION OF AKARA (DEEP-FAT FRYING OF COWPEA PASTE)

Recent trends in food processing have emphasized the development and improvement of reduced fat foods. The objective of this study was to evaluate the effectiveness of edible coatings formulated from hydroxypropyl methylcellulose, methylcellulose, corn zein, and amylose in restricting oil absorption during deep-fat frying of akara, a traditional West African food made from whipped cowpea paste. Effectiveness of two methods of coating application (spraying and dipping) were examined. Portioned balls of akara paste were partially-fried in peanut oil for 100 s at 193C. Coatings were applied, dried, and the product was frozen at -18C. After thawing, samples were finish fried at 166C to an internal temperature of 70C. Total moisture content of all coated samples was significantly higher than the control. Coated akara absorbed significantly less oil than the control for both sprayed and dipped applications. For both applications, the coated samples appeared to be soggy and less brown when compared to the control samples.     

EFFECT OF PROCESSING VARIABLES OF COWPEA (VIGNA UNGUICULATA) MEAL ON THE FUNCTIONAL PROPERTIES OF COWPEA PASTE AND QUALITY OF AKARA (FRIED COWPEA PASTE)

The importance of particle size distribution in conjunction with milling method (dry‐milled hammer‐milled meal [HM] or wet‐milled freeze‐dried meal [FD]) on the functionality of cowpea paste and textural characteristics of akara produced from dry meal was investigated. All meal samples contained a minimum of 65% by weight medium‐sized particles and different combinations of large and fine particles to compose the balance. With the exception of the pastes made from meal consisting of 35% fine particles, all pastes had good foaming ability and handling characteristics. However, akara made from the HM and FD blends with 35% large particles had hardness values not significantly different from the traditionally prepared (wet‐milled) akara (5.317, 4.048 and 5.341 N, respectively), indicating that the meal blends had the potential to produce akara acceptable to consumers.     

EVALUATION OF THE SENSORY QUALITY OF AKARA (FRIED COWPEA PASTE) BY TEENAGE CONSUMERS

Cowpeas (Vigna unguiculata) are a nutritious legume, but their consumption in the U.S. is limited by the lack of convenience and innovative forms of use. Akara is a popular West African food made from deep-fat fried cowpea paste and has potential for extending the use of dry cowpeas in U.S. markets. Acceptance tests involving 122 Georgia teenagers were conducted to assess their response to akara. Akara made from decorticated seeds was more acceptable than akara made from nondecorticated seeds. Akara was most acceptable to males, blacks, and to those who had completed nine or more grades in school. The product was more likely to be consumed at a restaurant or cafeteria than at home or at a fast food establishment. These findings indicate that akara has potential for success in the fried food market and could be targeted toward certain segments of the teenage population.     

QUALITY AND CONSUMER ACCEPTANCE OF AKARA (FRIED COWPEA PASTE) PROCESSED FROM WET- AND DRY-MILLED COWPEA (VIGNA UNGUICULATA) MEAL WITH SPECIFIED PARTICLE SIZE DISTRIBUTION

Direct quality indicators of cowpea paste and akara produced from traditionally wet‐milled peas, and hammer‐milled (dry‐milled) and freeze‐dried (wet‐milled) meals were examined in this study. Both meal samples studied were formulated to consist of 65% medium‐sized particles and 35% large particles by weight. Particle volume mean diameters (µm) of the three paste samples were not significantly different from one another at the various stages during akara production. Scanning electron micrographs of akara crumb were converted to threshold images and analyzed. There was no significant difference in the amount of air found in the akara samples. Akara produced from both meals was found acceptable by sensory panelists with no significant difference in any of the attributes or overall liking among the three samples.     

Improving the nutritional quality and maintaining consumption quality of akara using curdlan and composite flour

Soybean flour and curdlan were incorporated into cowpea flour to determine their effect on lowering the fat content and on the physical properties of akara. At 20% substitution, soybean flour lowered the fat content of akara by 7.7% and increased the protein content by 28.7% without significantly affecting the firmness or the colour of akara. Addition of 1% curdlan decreased the fat content by 32.2% but significantly increased the firmness of akara and produced a darker‐coloured product. The paste moisture content of akara containing 20% soybean flour and 1% curdlan was modified to obtain product characteristics comparable with the control (100% cowpea flour) while maintaining a lower fat content. Optimum results were obtained for paste with 63% moisture content. Firmness of this modified product was similar to the control and the fat content was lower (17%) compared with the control (26%).     

PROCESSING AND ACCEPTABILITY OF FRIED CASSAVA BALLS ("AKARA-AKPU") SUPPLEMENTED WITH MELON AND SOYBEAN FLOURS

The processing and acceptability of fried cassava balls (“Akara‐akpu”) supplemented with melon and soybean flours were studied. Cassava flour, defatted soybean flour and cassava mash were produced. Some functional and chemical properties of the flours were determined. Akara‐akpu prepared from 100% cassava mash served as control; 100% cassava flour, 80% cassava flour + 20% defatted soybean and 70% cassava flour + 30% defatted melon flour were prepared. Akara‐akpu balls were subjected to chemical and physical analyses. Akara‐akpu prepared from composite flour blends had higher protein, fat, ash and energy value than Akara‐akpu from 100% cassava mash. The cyanide content and degree of starch gelatinization of Akara‐akpu prepared from 100% cassava mash (control) were higher than Akara‐akpu prepared from cassava mash plus composite flour blends. There was a significant difference (P ≤ 0.05) in weight and yield between Akara‐akpu prepared from 100% cassava mash (control) and cassava mash plus composite flour blends. There was no significant difference (P ≤ 0.05) in volume between Akara‐akpu made from control sample and those cassava plus composite flour blends.     

Effects of Pre-decortication Drying Treatment on the Microstructure of Cowpea Products

A pretreatment process developed to prepare cowpeas for mechanical decortication by dry abrasion involves wetting, equilibrating, and drying. Drying temperatures of 50°C, 70°C, 90°C, 110°C, and 130^°C affected the microstructure of cowpea seeds, meal and akara (fried cowpea paste). Severe heat treatment damaged the middle lamella of cotyledon cells, changed the birefringence property of starch granules, reduced the amount of air incorporated in whipped paste and produced akara with a nonuniform, dense structure.     

Protein Nutritional Quality of Traditional and Novel Cowpea Products Measured by In Vivo and In Vitro Methods

Effect of processing on nutritional quality of cowpea meal protein was determined by in vivo and in vitro methods. Uncooked meal and meal which had been extruded at various temperatures and moistures; slurried, steamed, and drum-dried (SDP); and hydrated to a paste and deep-fat fried (akara) were studied. PER values of extrudates (1.81–1.97), and akara (1.89) were higher than those of raw meal (1.44) or steamed, drum-dried paste (1.63). The saturation kinetics model showed similar trends but differences were not significant. In vitro digestibility was highest for extrudates (83–85%), intermediate for akara and SDP (82.8%, 81.2%), and lowest (77.8%) for raw meal. C-PER/DC-PER gave differing and contradictory results.     

Effect of Soy Flour and Maize Flour Addition on Phase Separation in Moi-Moi from Soaked Cowpea (Vigna unguiculata) and Cowpea Flour from Different Cowpea Varieties

Two improved varieties of cowpea (IT89KO and IT90K-76) and one local variety (lsiocha) were used to investigate the effects of added soyflour and maize flour on the phase separation in moi-moi made from soaked cowpea and cowpea flour. Different levels (5%, 10%, 15%, 20% and 25%) of maize flour, soyflour and a 1:1 blend of soyflour and maize flour (soy/maize flour) were separately added. The moi-moi from the different combinations was evaluated for phase separation and per cent height of the upper layer calculated. Soaking of cowpea reduced the size of the upper layer in moi-moi compared with the use of cowpea flour. The addition of maize flour or the soy/maize flour reduced the upper layer compared with when either flour was added alone. The upper layer of moi-moi made from cowpea flour with added soy flour (21.20%) was significantly higher (p < 0.05) than moi-moi from soaked cowpea with added soy flour (15.2%). Moi-moi with added maize flour made from cowpea flour produced a significantly (p < 0.05) higher mean per cent upper layer (19.72%) compared with that from soaked cowpea (8.95%). Addition of soyflour produced the greatest upper layer for all varieties used. There were no significant (p > 0.05) differences in the per cent upper layers for moi-moi from all cowpea varieties when maize flour was added. Increasing the proportion of added flours increased the size of the upper layer. Complete prevention of the occurrence of phase separation in moi-moi by addition of soy flour and maize flour alone is not feasible.     

THE EFFECTS OF FLAXSEED, SOY AND CORN FLOURS ON THE TEXTURAL AND SENSORY PROPERTIES OF A BAKERY PRODUCT

The objective of this study was to assess the effects of some healthy ingredients on the properties of a ring‐shaped bagel/pretzel‐type bakery product to offer an alternative product satisfying consumer demand. For this purpose, ground flaxseed, defatted soy flour and corn flour were blended at a weight basis with wheat flour at 5, 10 and 15%. The taste score decreased upon increasing the level of substitution of flaxseed, soy and corn flours. Samples containing 15% of flaxseed were rated poorest in taste. No significant difference was observed in crust color except 15% level of flaxseed. The control sample had highest crust color value. The crispness scores of control and other samples containing 5% corn flour were higher than that of other samples. The samples with 5% flaxseed flour had lower crust L values. Flaxseed, soy and corn flour showed significant effects on the hardness, cohesiveness, springiness, gumminess, fracture force and stiffness values (P < 0.05). Samples with 15% corn flour had the highest hardness value. The results of the present study suggest that flaxseed, soy and corn flours could be added to a typical snack formulation up to levels of 10% with a reasonable acceptance offering promising nutritious and healthy alternative to consumers.     

Influence of cowpea (Vigna unguiculata L Walp) variety on protein quality and sensory properties of akara,a popular West African cowpea‐based food

The influence of newly developed cowpea varieties (IT81D‐699, IT82E‐18, IT84S‐2246‐4 and TV_x3236) on the proximate composition, protein quality and sensory properties of akara, a popular West African cowpea‐based food, was investigated and the results obtained were compared with those for akara prepared from a local blackeye cowpea variety. Protein quality was evaluated using weanling albino rats fed diets which were formulated to supply 10% protein using defatted akara samples, with casein as a control. Akara samples prepared from IT81D‐699 and TV_x3236 had crude protein contents, texture and overall acceptability comparable to those of akara prepared from the blackeye variety. Also, akara diets formulated using IT81D‐699 and TV_x3236 showed significantly (p < 0.05) higher values for weight gain, protein efficiency ratio, net protein ratio and true digestibility than diets formulated with IT82E‐18, IT84S‐2246‐4 and blackeye, suggesting an improvement in the nutritional quality of akara produced using these (IT8ID‐699 and TV_x3236) newly developed cowpea varieties. Copyright © 2004 Society of Chemical Industry     

Effect of soybean substitution for cowpea on physical,compositional, sensory and sorption properties of<Emphasis Type="Italic"> akara</Emphasis> Ogbomoso

Akara Ogbomoso was prepared from cowpea:soybean flour mixture ratios of 100:0, 80:20, 60:40 and 40:60. Physical, compositional, sensory and sorption characteristics of the akara were evaluated. Protein and fat content increased, while carbohydrate content decreased as the soy content of the flour mixture of akara Ogbomoso increased. There were no significant differences (P<0.01) in the colour, taste, aroma and overall acceptability for either the freshly prepared akara Ogbomoso or the akara Ogbomoso stored for 10 weeks. There were significant differences (P<0.01) in crunchiness, increasing as the soy substitution increased both in the freshly prepared and stored akara Ogbomoso. The adsorption isotherms of akara Ogbomoso varied with varying levels of soy substitution and at 20, 30 and 40 °C, had sigmoid shaped, type II isotherms according to Brunauer-Emmet-Teller (BET) classification, and were affected by temperature and composition. Increased levels of soy substitution and temperature depressed the isotherms. Calculated monolayer moisture contents using BET and Guggenhein Anderson deBoer models decreased with increasing soy substitution and temperature.     

Functional Properties of Cowpea Paste as Influenced by Indigenous Microflora

The influence of indigenous microorganisms on several functional properties of cowpea (Vigna unguiculata) paste was investigated. Six formulas [with and without onion, salt and pepper; inoculated (indigenous microflora) and uninoculated] were prepared and incubated for 24 hr at 30°C. Lactic acid bacterial populations were similar to total aerobic microbial populations which increased with time of incubation. Pastes containing salt were associated with high equilibrium moisture contents. As incubation time progressed, pH and emulsion capacity decreased and specific gravity and apparent viscosity increased, while oil and water binding capacity remained unchanged. Formula content and incubation time did not influence the color of cowpea pastes; however, akara, a deep-fat fried product prepared from the paste, did have a darker color when made from paste which had been incubated for 24 hr.     

Foam-mat drying of cowpea (<Emphasis Type="Italic">Vigna unguiculata</Emphasis>) using glyceryl monostearate and egg albumin as foaming agents

Foam-mat drying of cowpea using glyceryl monostearate (GMS) and egg albumin (EG) as foaming agents was investigated. GMS and EG were incorporated into cowpea paste (22%, 25% and 28% total solids) at 2.5, 5.0, 7.5, 10.0, 12.5 and 15% (w/w), and whipped for 3, 6, 9, 12, 15, 18 and 21 min, maintaining 15, 25 and 35 °C foaming temperatures. Foam density was measured and expressed in g/cm³. Cowpea foams were dried at 60 °C (Twb, wet bulb temperature 35 °C) for 48 min. Sensory attributes of akara produced from fresh and reconstituted pastes were evaluated.Generally, foam density decreased with increased concentrations of GMS and EG in cowpea paste. Foam density decreased with decrease in total solids of cowpea paste. Minimum foam densities were obtained in cowpea foams with GMS and EG after 9 and 21 min of whipping, respectively. EG-stabilized foams were unstable for drying. Sensory evaluation showed no significant difference (P>0.05, 0.01) in the quality attributes of akara produced from fresh and reconstituted GMS-stabilized cowpea powders.     

Effect of Holding Time on the Functionality of Cowpea Paste and Quality of Akara

Whipped cowpea pastes were held at room temperature (20°C) for 0, 30, 60, 120, and 240 min before preparation of akara (fried cowpea paste). Apparent viscosity of whipped paste was measured at different shear rates (0.17, 0.34, 0.85, 1.70, 3.40, 6.80, and 17.00 sec^?1). At any given shear rate, paste became more viscous with increasing holding time. Akara became darker and less yellow in color as paste holding time increased. Akara made from paste held 120 min or longer had an unacceptably dense, firm texture.