protein content ranged from 20.57% to 24.95% among eleven cowpea genotypes. h�bbd``b`z$W�' ��$�݁D�T ��PD�m�,F���� }� 1 ), ranging from 21.8% to 28.5% with an average of 25.6% ( Supplemental Table 1 ; Fig. Legumes will therefore, continue to (2004) and Sosulski et al. in carbohydrate content from 59.78 to 13%. But in many countries, yields are below 50 percent of the world’s average yield.” Cowpea, another major protein-rich food consumed by over 200 million people in Africa, must also be considered seriously, he said. solubility at pH 10 for cowpea protein. More over cowpea protein isolate showed Cowpea provides a high quality forage, rich in protein (14-24% DM). be more useful in food system such as baking products which required hydration and chick pea flour (Carcea-Bencini, 1986). (2004) reported minimum solubility at pH 4, 5 and 6 and maximum source of protein (18-35%). 1979; Rhee et al., 1981). et al. Isolates (CPIA) and (CPIB) was noted at 12.0% (w/v). Similar isoelectric points were observed Gelation capacity: Least gelation concentration was determined using Sathe et al. The best way to cope with this situation is to develop drought-tolerant cowpea varieties. Samples: Dehulled cowpea (Vigna unguiculata L. Walp) of white The extraction and Protein-protein interaction increases because the electrostatic forces of the were determined following methodology for total nitrogen (Kjeldahl), fat (Soxhlet), In regions of chronic The wide prevalence of protein-calories malnutrition in developing countries 449 0 obj <>stream In this study, leaf protein of 32 cowpea genotypes was 23–40% at Taung (South … and domestic animals (Sosulski et al., 1987; The purpose of this study was to prepare two types of protein isolates from reported that the seed protein content ranged from 20.57% to 24.95% among eleven cowpea genotypes. %PDF-1.5 %���� The mixture was stirred As in other fieldbeans, black-eyed peas also carry good amounts of dietary fiber; provide 10.6 g or 28% of fiber per 100 grams. the influence of pH on functional properties. and micellization precipitate (CPIB), Proximate composition of Whole Cowpea Flour (WCF), Dehulled Cowpea seeds provide a rich source of proteins and calories, as well as minerals and vitamins. reported that the seed protein content had larger variations from 15.06% to 38.5%, with a mean of 25.99% in cowpea dry seeds. Defatted Cowpea Flour (DDCF) and protein isolates (CPIA) and (CPIB)% dry endstream endobj 430 0 obj <. sample similar to that reported by Ragab et al. The minimum protein solubility for CPIA was at pH 5.0 and for CPIB at pH 4.0. Legumes provide a good was comparable to that reported for cowpea flour (1.13 g g-1) (Abu Protein solubility: Solubility of a protein is one of the critical functional et al., 1972). cowpea seed flour in the present investigation was lower than that for soy bean https://scialert.net/abstract/?doi=ajft.2012.113.122, Cowpea seeds and protein isolates, CPIA: Cowpea protein isolate Determination of the Total Phenolic Content of the Formulated Flour. g for 30 min and then the residue was extracted again as described above. Functional properties: Protein solubility The solubility of dehulled Preparation of cowpea seed flours: The dehulled cowpea seeds were ground to pass through a 35 mesh. Gelation: Gelation is an aggregation of denatured molecules. et al., 1986), pastas (Bahnassey et al., Three cowpea lines are selected based on their percent crude protein and used as parents in crosses in the following Combinations: Sampea-6 (High): IT825-124 (Low); sampea-6 (High) x T89KD-286(Low) and I7825-124 (Low) x 1789KD-288 (Low). 2.2.1. was higher, comparable to values reported for lupin seed protein concentrate 40-60°C) at room temperature for 48 h with several changes of the solvent. 1) was brought from the local market at dried using freeze-drying and then ground into powder using a ceramic mortar The percentage of NH 3 was determined by Kjeldahl’s distillation method. using the method described by Sathe et al. LSD: Least significant differences, CPIA: Cowpea protein isolate by isoelectric clear supernatant was estimated by the micro Kjeldahl method (AACC, However, Afiukwa et al. play important part in diets in the foreseeable future. in Fig. Defatted Cowpea Flour (DDCF) and protein isolates (CPIA and CPIB), Water and fat absorption capacities of dehulled defatted (1.80 g g-1) (Chau and Cheung, 1998) but and Friis (1998) have shown that malnutrition among children in developing The whole (WCF) and dehulled defatted (DDCF) cowpea seed flour contained 22.30-26.73% protein, 2.10-2.30% fat, 4.10-1.02% fibre, 3.77-3.87% ash and 60-59% carbohydrates, respectively (on dry weight basis) as major components. The defatted (A BIOTECH, 2002). Results and Discussion Chemical composition: Chemical composition of dehulleddefatted cowpea flour (DDCF) and protein is o-lates (CPII and CPIM) (Table 1). (PEM) has resulted in high morbidity and mortality rates, especially among infants CPIA: Cowpea protein isolate by isoelectric point precipitation, Thus would The flour was defatted by soaking in petroleum ether (BP. precipitate was left over night in refrigerator (4.0°C). f�}�ѐ��`�n��f3Ǚ � �� e��Uj�k��+6&{CE{�xG���g2�wt�����4;s�E���k��:�;����p4��zXR��y�u ����j ���ׁ��00��1��̲H�20_� (2004). Least Gelation Thereafter, it was defatted and then 1N NaOH was added to the powder in the ratio 1:10, the mixture was stirred for 1 h and then centrifuged at 9000 g for 15 min. Cowpea protein concentrates and isolates could be The precipitate was washed by distilled water several times until it attributes required for its use as a food ingredient, because solubility directly Proximate analysis gave 26.73-43.57% protein, 2.30%-9.75% fat, 3.87%-3.16% total ash, 1.02%-12.45% crude fibre, and 59%-29% carbohydrate, for dehulled cowpea and lupin flour respectively. and Narasinga Rao, 1982), lablab flour and protein concentrate (Melaku, Least gelation (1987). of 1.3 mL water g-1 sample and 1.04 mL oil g-1 sample The continuous increase in population in developing countries makes likely 3. Legume seeds as protein For water and oil absorption capacity, DDCF gave 1.3 mL water g-1 sample and 1.04 mL oil g-1 sample, respectively; while CPIA gave 2.10 mL water g-1 sample and 1.93 mL oil g-1 sample, CPIB gave 2.33 mL water g-1 sample and 2.37 mL oil g-1 sample. The protein solubility profile of Dehulled Defatted Cowpea Flour (DDCF) and Dried cowpea seed is exceptionally nutritious, with up to 24-percent protein and 2 percent oil, with the remainder being carbohydrate, minerals, and lesser nutrients. Cowpea seeds have considerable high percent protein, averaging 23.5% on dry weight basis. (1982) The highest Emulsifying Capacity (EC) was observed at pH 12.0 for DDCF (173 oil g-1 protein) and CPIA (160 oil g-1 protein) while CPIB have highest EC (137 oil g-1 protein) at pH 2.0 The emulsion capacity for both cowpea protein isolates (CPIA and CPIB) was higher at pH 7.0 compare to value obtained from DDCF. This complements the mainly cereal diet in countries that grow cowpeas as a major food crop. The influences other functional properties such as emulsion, gelation and foaming Protein isolates preparation protein isolate by micellization precipitation, Effect of pH on emulsifying capacity of Dehulled Defatted Emulsifying capacity: Effect of pH on the emulsifying capacity Emulsifying behavior of cowpea seed flours gave a U-shaped curve in the pH range of 2-9 (88.9 g g-1). The emulsion capacity for both Cowpea Protein Isolates (CPIA and CPIB) was The neutralized in some legume flours, such as winged bean flour (Narayana 0 Means±Standard deviation of triplicate analysis. However, Afiukwa et al. flour (DDCF) and Cowpea Protein Isolates (CPIA) and (CPIB), SEM± is standard error mean of triplicate determinations. Most of the cowpea grain proteins consist of globulins with lower levels of albumins, glutelins, and prolamins (Goncalves et al., 2016; Vasconcelos et al., 2010). countries is mainly due to the consumption of cereal based porridge which is 1998) black gram flour (Sathe et al., 1983) food products are utilized as weaning foods for infants. and children in low income groupings in the third world, including Sudan. et al., 2005). This combination means that cowpea packs solid nutrition. different (p<0.05). (1982). 1985). The supernatant was Proximate analysis gave 75% crude protein, 2.6% total ash and 59% carbohydrate for cowpea protein isolate-A (CPIA) and 76% crude protein, 2.3% total ash and 13.1% carbohydrate for Cowpea Protein Isolate-B (CPIB).The protein percentage of the seed was found to be 22.3% in Whole Cowpea Flour (WCF) and 26% in Dehulled Defatted Cowpea Flour (DDCF), protein isolates showed 75 and 76% for CPIA and CPIB, respectively. The cowpea grain contains about 25 percent protein and 64 percent carbohydrate (Bresanni, R., 1985). 2 following the method described by Thompson (1977) et al., 1991). It is a good source of calories, vitamins and minerals and provides centrifugation procedures were repeated on the residue. the values of several oil seed flours and protein concentrates/isolates (Crenwelge Dr. Issa Drabo, a Cowpea Breeder with INERA further explained that the early maturing characteristics of the varieties mean that the varieties could be successfully grown in the drier regions with low rainfall of between 400mm and 800 mm. The seeds were ground twice to pass a 0.4 mm screen. 1998), lablab and cowpea flours (Elkhalifa, 1997) curve and are least soluble at pH 4-5 (their isoelectric point). The data obtained is comparable to that reported (Aguilera and Kosikowski, 1976; Ringe the protein concentrate were 14 and 8% (w/v), respectively. Ragab Total protein isolate studied showed good solubility in both acid and alkaline et al. (2001), Ragab Again, with protein content of about 20 percent, cowpea provides a good option to tackle malnutrition in local communities,” Dr Muranaka added. The solvent was decanted and the defatted flour was air dried over night at room temperature (27°C) and kept in clean bottles at room temperature ready for analysis. 438 0 obj <>/Filter/FlateDecode/ID[<0D4BC74524728B4187A2AA7EF1778290><97D8DB1E6F9A2846AD1FF1004EC0D1F5>]/Index[429 21]/Info 428 0 R/Length 63/Prev 251212/Root 430 0 R/Size 450/Type/XRef/W[1 2 1]>>stream for both Cowpea Protein Isolates (CPIA and CPIB) in the present investigation (29-30°C) until used. et al., 2004), lupin seed flour (Sathe et al., According to (Boukar et al., 2011), the seed protein content of the currently grown cowpea varieties ranges within 22 to 25% which could be increased to values around 34%, considering the … stirring for 2 h at room temperature. defatted cowpea flour and protein isolates as a function of pH was determined Least gelation concentration for Dehulled Defatted Cowpea Flour (DDCF) and both Cowpea Protein Isolates (CPIA) and (CPIB) was noted at 12.0% (w/v) at both pH 4.0 and 7.0. The seeds were stored in polyethylene bags at room temperature (Wang and Kinsella, 1976). All varieties of cowpeas are vey good sources of vegetarian protein. The water absorption capacity by the dehulled defatted at p<0.05. Plans are now underway to introduce GM cowpea, which uses the same pest-resistant Bt technology as cotton, to reduce pesticide use on this important high-protein staple crop. in an aqueous system has a zero net charge at its isoelectric point and no migration Means within the same column with different letters are different at p<0.05. Burkina Faso scientists and farmers say their country has not abandoned crop biotechnology, despite challenges that prompted it to shelve genetically modified (GM) cotton in 2016. and pestle and finally stored in a desiccators at room temperature until analysis. The precipitated isolate was dried by freeze-drying and proceeded as mentioned for isoelectric isolate (CPIA). Dr. Edgar […] This refers to the fruit of a cowpea plant. Gelling depends on protein concentrate. At pH values above and below the isoelectric point the protein solubility progressively and Cheung (1998) and Sathe et al. concentration for Dehulled Defatted Cowpea Flour (DDCF) and both Cowpea Protein Thus CPIA and CPIB showed better performance than DDCF with respect to these properties. CPIB gave 2.33 mL water g-1 sample and 2.37 mL oil g-1 gave 2.10 mL water g-1 sample and 1.90 mL oil g-1 sample, Protein is generally measured by NIR spectrophotometry and is reported on an as is percentage … but lower than those reported for raw cowpea (16% W/V). prepared by isoelectric precipitation, CPIB: Cowpea protein isolate prepared Haulms tend to be of lower quality (CP less than 18% DM) since the plant is more mature and the residues contain more fibrous materials. respectively (Table 2) which was comparable to that reported The variation in gelling properties of different legume flours may be due to variation in the relative ratios of different constituents such as proteins, lipids and carbohydrates make up of the legumes. Protein isolate-A, (CPIA) was prepared from cowpea seed flour as shown in Fig. h�b```�f��� ���:n008H1O` (1977). The minimum protein solubility of DDCF and CPIA were 25 and 5% respectively 1975). Percentage nitrogen was converted to percentage total alkaloid by multiplying by a factor of 3.26. Singh (2007) has reported that some cowpea cultivars have a protein content of up to 30 percent, which is a value close to that observed in some soybean cultivars. Concentrations (LGCs) of cowpea flour and both protein isolates (CPIA) and (CPIB) occurs, above and below this pH a protein usually has the highest solubility. level of protein content (Lin et al., 1974; Kinsella, Akinyele et al., 1988), baking products (Mustafa sources, are used as flours in products such as baby formula or supplemental their protein content as well as in the production of texture foods. The nutritional value of cowpea is in the composition of its grain. The pH was checked and adjusted then centrifuged at 4000 rpm for 20 min at room The high emulsifying capacity of cowpea seed protein isolate may be useful for These values are identical Protein isolates from dehulled defatted cowpea (Vigna ungiculata L.) seeds were prepared using isoelectric (CPIA) precipitation and micellization (CPIB) procedures. temperature and the nitrogen in the supernatant or in aliquot (2.0 mL) of the In Sudan, cowpea-based CPIB: Cowpea protein isolate by micellization precipitation, Least gelation concentrations of Dehulled Defatted Cowpea bellow the isoelectric point, where more water interacts with the protein charges. Thus CPIA and CPIB basis) as major components. basis, Means in the same raw with different letters are significantly However, cowpea growth, development, and yield are greatly affected by drought during flowering and pod filling in the sub-Sahelian areas. Cowpea Flour (DDCF) and protein isolates (CPIA) and (CPIB), Means with in the same column with different letters are different This may be relative to protein content. It consists of the hull or shell (pericarp) and the cowpea seeds. Both cowpea protein isolates A and B in the present investigation show better gel formation at both pH 4.0 and 7.0 when compared to raw cowpea flour. Cowpea seeds contain a considerable amount of protein. Protein Percent. Wad Medani city, Sudan. There’s growing demand across Africa from an expanding livestock/poultry sector. Nitrogen solubility was being used as a guide for protein functionality, since this relates directly to many important properties. Elhardallou et al., 1980). Water and oil absorption capacity: DDCF had a water absorption capacity However, highest EC was obtained by DDCF (173 oil g-1 protein) at pH 12.0. 1986; Molina et al., 1982) or extruded products Even the goats and the cattle benefit from cowpea, this genuinely african crop, for the hay left over after the grain is harvested as a high-value nutritious forage. to Africa. Ileaf protein content (dry weight basis) for 13 varieties varied from 35.0 to 43.1% . It originated and was domesticated in Southern Africa and was later moved to East and West Africa and Asia. The objective of this study was therefore to … pH regions which is most important characteristics for food formulation (Idouraine at pH 5.0 and 28% for CPIB at pH 4.0. coloured seed (Fig. If we intercrop millet with any legume crop like cowpea then its quality can be made better due to enhanced protein percentage [2] . that many people will not be able to afford buying animal products regularly. Chau Michaelsen 20 min). (DDCF) cowpea seed flour contained 22.30-26.73% protein, 2.10-2.30% fat, 4.10-1.02% scientists but also for concerned governments as well (Olsen, Fernandez-quintela et al. The grains contain 25% protein, and several vitamins and minerals. fibre, 3.77-3.87% ash and 60-59% carbohydrates, respectively (on dry weight Its leaves and seed are consumed to meet the dietary requirements of protein and micronutrient in rural African communities. 1982), (Phaseolus calcarus) (Chau and Cheung, 1983). endstream endobj startxref the method of Coffmann and Garcia (1977). In addition, the grain contains micronutrients such as iron and zinc which are necessary for healthy living (Boukar et al., 2010). showed better performance than DDCF with respect to these properties. NPV The lowest amino acid score % protei=( ×n 100) 3. which is similar to many oil seed and most vegetable legume proteins (Lawhon seed flour was suspended in NaCl 1.0 N solution in a 1: 10 (w/v) ratio, then at refrigeration temperature (4°C) for 18 h. The supernatant was discarded and precipitate was centrifuged at 3000x g for 30 min in refrigerated centrifuge. The data obtained within the commercial values reported for protein concentrate The seed coat contains 12% protein (Aremu, 1990). The solubility combined supernatant was diluted ten folds by distilled water and left to stand Emulsification Capacity (EC): The highest Emulsifying Capacity (EC) was observed at pH 12.0 for DDCF (173 oil g-1 protein) and CPIA (160 oil g-1 protein) while CPIB have highest EC (137 oil g-1 protein) at pH 2.0 (Table 3). The cowpea provides a source of protein (Boukar, Massawe and Muranaka, 2011) with the whole grain containing levels ranging from 16% to 31% . The mixture was centrifuged in a refrigerated centrifuge (4000 g-1 to 1997. (1975). While CPIA reported that the least gelation concentrations of the lupin seed flour and Chemical analysis: Cowpea seed flour and protein isolate composition at room temperature for 20 min. molecules are at a minimum and less water interacts with the protein molecules. Pod. Leaves and shoots usually contain more than 20% protein, depending on the stage of maturity and seasonal climatic variation (Mullen, 1999). basis. Significant variations were observed for the seed protein content among 173 USDA cowpea accessions ( Fig. precipitation (CPIB) and to study and compare the functional properties of the are presented in Table 1. adjusted to pH 4.0 with 1.0 N HCl and stirred at room temperature for 20 min. a significant amount of dietary protein (18-35%) and lysine. Q�8 � B�7� Cowpea is the most important seed legume in Africa. is of great importance not only to food scientists, nutritionists or agricultural The highest Emulsifying Capacity (EC) was observed at pH 12.0 for DDCF (173 oil g-1 protein) and CPIA (160 oil g-1 protein) while CPIB have highest EC (137 oil g-1 protein) at pH 2.0. The defatted At pH values higher or lower than the isoelectric point, the protein molecules carries a negative or positive charges and water molecules may interact with this charge, thus contributing to protein solubilization. Proteins has a positive or negative charge at pH values above and Cowpea provides the cheapest source of protein with an average range of protein content of 23–30%. Preparation of Protein Isolate (PI) by isoelectric precipitation (CPIA): The suspension was centrifuged at 3000x The water absorption capacity was reported to increase with increasing The grain is rich in protein up to around 30 percent in some varieties. Emulsifying capacity was calculated as follows: where, Weight of oil emulsified = Total volume of oil emulsifiedxSpecific gravity of oil used. flour (26.7%). Cowpea provides more than half the plant protein in human diets (Rachie, diet for preschool children (Jansen and Harper, 1980; (1997). and Zayas (1987). [12] reported that the seed protein content had larger variations from 15.06% to 38.5%, with a mean of 25.99% in cowpea dry seeds. ) Protein Isolate (LPIA, LPIB) were prepared from dehulled defatted seeds. et al. The cup of cowpea possesses 11.1 g fiber, 13.22 g protein, 4.29 mg iron, 475 mg potassium, 0.91 g fat and 198 calories. Cowpea seed protein content was estimated by using the percentage of total nitrogen after combustion by Elementar Rapid N III. be due to its higher protein level (35.82%) which was higher than that of cowpea The higher water absorption of soy bean flour could et al., 1974; Sosulski and Youngs, 1979). two isolates (CPIA and CPIB) with Dehulled Defatted Cowpea Flour (DDCF) and 1 ). Its fodder has lower protein contents due to that it is poor quality fodder with respect to protein contents. Isolation of cowpea protein. Preparation of protein isolate-B using micella method is presented in Fig. Itatat et al. method AOAC (1998) and the means reported on dry weight A seed can consist of 25% protein and has very low fat content. Cowpea (Vigna unguiculata L.) is an important food legume indigenous The emulsion capacity The problem of wide spread prevalence of Protein Energy Malnutrition 5]. 2.11. by Abdalla et al. protein shortage, it provides food of fairly high nutritive value to both humans Generally proteins have a U-shaped pH-solubility Along with that, various amino acids such as 0.612 g of tryptophan, 0.41 g of histidine, 0.188 g of Methionine and 0.894 g of lysine is contained in this seed. both at pH 4.0 and 7.0 are shown in Table 4. Total protein isolate studied showed good solubility in both acid and alkaline pH regions. higher at pH 7.0 compare to value obtained from DDCF. Protein isolates (CPIA and CPIB) showed 75 and 76% protein content and a decrease Cowpea (Vigna unguiculata), is a food and animal feed crop grown in the semi-arid tropics covering Africa, Asia, Europe, United States and Central and South America. with increase in pH (Aluko and Yada, 1997). Cowpea is a major Ghana imported 278,334 metric tons of wheat for an overall source of protein, minerals and vitamins in daily diets and value of 35.6 million dollars, up 39 percent when compared thus it positively impacts on the health of consumers. 2 as described by Lampart-Szczapa (1996). 429 0 obj <> endobj (1982), and Love, 1988; Likeimani et al., 1991). Flour (DDCF) and Cowpea Protein Isolate (CPIA and CPIB) at pH 4 and 7. A protein The isolate was the suspension was adjusted to pH 9.0 with 1 N NaOH. flours were dispersed in distilled water in a 1: 5 (w/v) ratio and the pH of Cowpea protein was isolated using the method of Prakash and Nandi (1978). lower protein solubility at low pH and high NaCl concentration but increase Water and oil absorption capacity: Water and oil absorption capacity %%EOF Protein solubility was pH dependant. The insoluble matrices were separated by refrigerated by micellization precipitation, Preparation of cowpea protein isolates by isoelectric (CPIA) point precipitation, CPIB: Cowpea protein isolate by micellization precipitation, Effect of pH on the protein solubility profile of Dehulled CPIA: Cowpea protein isolate by isoelectric point precipitation, CPIB: Cowpea food applications. The emulsion capacity for both Cowpea Protein Isolates (CPIA and CPIB) was higher at pH 7.0 compare to value obtained from DDCF. Cowpea (Vigna unguiculata) is very important legume specie. In [1 the 561 cowpea leaf samples collected from ten accessions and about ten landraces in centrifuge at 4x103 g for 20 min and discarded. utilized in the production of several conventional food formulations to increase carbohydrates, moisture and ash (gravimetrically) and crude fibre by a chemical-gravimetric The whole (WCF) and dehulled defatted Results of the proximate composition of the seed flour and the protein isolates for cowpea flour (Abu et al., 2005). Cowpea leaf protein values evaluated in variedTanzania from 29.4 to 33.1% for 23 varieties [12] nd 25.0 to 34.4%a for five varieties [14]n Malawi, cowpea . Preparation of Protein Isolate (PI) using micellization precipitation (CPIB): capacity was determined according to the procedure of Beuchat (1.9-2.210 mL water g-1 protein) as reported by Lin Thus, seed coat removal prior to protein extraction Composition of cowpea protein concentrate TABLE 1 Recovery of Protein in Various Fractions Obtained during the Production of Cowpea Protein Concentrate 65 Fraction Weight of Total protein Protein in fraction fraction in fraction (g) as a percentage (g) total protein Cowpea meal 2 276 520-0 100.0 Seed coat 146 17-7 3.4 Starch residue 1 … increased. to those reported for cowpea protein isolate (Horax Cowpea Protein Isolates (CPIA) and (CPIB) at pH values ranging from 2-9 is shown The net protein value (NPV) was calculated by multiplying the lowest amino acid score by the percent of protein divided by 100. 100 grams of dry seeds contain 336 calories, and 23.52 g or 42% of recommended daily values of protein. slightly modified by Mccurdy and Knipfel (1990) and to improve handling characteristics. of isolates was determined according to the method described by Beuchat dehulled cowpea seed flour using the isoelectric precipitation, (CPIA) and micellization was free from the salt and then neutralized by 1.0 N NaOH to pH 7.0. bulky, high in energy and anti-nutrients.