bellow the isoelectric point, where more water interacts with the protein charges. Protein isolates from dehulled defatted cowpea (Vigna ungiculata L.) seeds were prepared using isoelectric (CPIA) precipitation and micellization (CPIB) procedures. be more useful in food system such as baking products which required hydration The minimum protein solubility for CPIA was at pH 5.0 and for CPIB at pH 4.0. (1997). NPV The lowest amino acid score % protei=( ×n 100) 3. The minimum protein solubility of DDCF and CPIA were 25 and 5% respectively The wide prevalence of protein-calories malnutrition in developing countries The isolate was 1) was brought from the local market at The pH was checked and adjusted then centrifuged at 4000 rpm for 20 min at room The seed coat contains 12% protein (Aremu, 1990). 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. and micellization precipitate (CPIB), Proximate composition of Whole Cowpea Flour (WCF), Dehulled The seeds were stored in polyethylene bags at room temperature in carbohydrate content from 59.78 to 13%. basis) as major components. increased. Isolates (CPIA) and (CPIB) was noted at 12.0% (w/v). 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. 1982), (Phaseolus calcarus) (Chau and Cheung, 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. CPIA: Cowpea protein isolate by isoelectric point precipitation, and pestle and finally stored in a desiccators at room temperature until analysis. diet for preschool children (Jansen and Harper, 1980; source of protein (18-35%). (1975). to 1997. The emulsion capacity for both Cowpea Protein Isolates (CPIA and CPIB) was 429 0 obj <> endobj The data obtained within the commercial values reported for protein concentrate Fernandez-quintela et al. The extraction and (1.9-2.210 mL water g-1 protein) as reported by Lin endstream endobj 430 0 obj <. The whole (WCF) and dehulled defatted Leaves and shoots usually contain more than 20% protein, depending on the stage of maturity and seasonal climatic variation (Mullen, 1999). Functional properties: Protein solubility The solubility of dehulled Generally proteins have a U-shaped pH-solubility 1979; Rhee et al., 1981). flour (DDCF) and Cowpea Protein Isolates (CPIA) and (CPIB), SEM± is standard error mean of triplicate determinations. 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 Friis (1998) have shown that malnutrition among children in developing Again, with protein content of about 20 percent, cowpea provides a good option to tackle malnutrition in local communities,” Dr Muranaka added. 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. curve and are least soluble at pH 4-5 (their isoelectric point). were determined following methodology for total nitrogen (Kjeldahl), fat (Soxhlet), This may be relative to protein content. Proteins has a positive or negative charge at pH values above and Protein isolates (CPIA and CPIB) showed 75 and 76% protein content and a decrease of isolates was determined according to the method described by Beuchat Protein solubility was pH dependant. The percentage of NH 3 was determined by Kjeldahl’s distillation method. temperature and the nitrogen in the supernatant or in aliquot (2.0 mL) of the Similar isoelectric points were observed to those reported for cowpea protein isolate (Horax and Cheung (1998) and Sathe et al. 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. dehulled cowpea seed flour using the isoelectric precipitation, (CPIA) and micellization and children in low income groupings in the third world, including Sudan. 1983). food products are utilized as weaning foods for infants. Preparation of protein isolate-B using micella method is presented in Fig. fibre, 3.77-3.87% ash and 60-59% carbohydrates, respectively (on dry weight 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. protein shortage, it provides food of fairly high nutritive value to both humans reported that the seed protein content ranged from 20.57% to 24.95% among eleven cowpea genotypes. 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. was free from the salt and then neutralized by 1.0 N NaOH to pH 7.0. Protein isolates preparation The 449 0 obj <>stream the method of Coffmann and Garcia (1977). The defatted Samples: Dehulled cowpea (Vigna unguiculata L. Walp) of white capacity was determined according to the procedure of Beuchat flours were dispersed in distilled water in a 1: 5 (w/v) ratio and the pH of showed better performance than DDCF with respect to these properties. (PEM) has resulted in high morbidity and mortality rates, especially among infants to Africa. The water absorption capacity was reported to increase with increasing Thus CPIA and CPIB Protein is generally measured by NIR spectrophotometry and is reported on an as is percentage … 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 et al. Michaelsen 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. 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 … 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. Thus CPIA and CPIB showed better performance than DDCF with respect to these properties. the influence of pH on functional properties. %%EOF by micellization precipitation, Preparation of cowpea protein isolates by isoelectric (CPIA) The solubility slightly modified by Mccurdy and Knipfel (1990) and Dr. Edgar […] 3. the suspension was adjusted to pH 9.0 with 1 N NaOH. but lower than those reported for raw cowpea (16% W/V). Means within the same column with different letters are different at p<0.05. cowpea seed flour in the present investigation was lower than that for soy bean However, Afiukwa et al. both at pH 4.0 and 7.0 are shown in Table 4. A protein h�b```�f��� ���:n008H1O` was comparable to that reported for cowpea flour (1.13 g g-1) (Abu Legume seeds as protein Emulsifying capacity: Effect of pH on the emulsifying capacity Emulsifying et al., 2004), lupin seed flour (Sathe et al., Cowpea (Vigna unguiculata) is very important legume specie. The problem of wide spread prevalence of Protein Energy Malnutrition The precipitated isolate was dried by freeze-drying and proceeded as mentioned for isoelectric isolate (CPIA). Chau play important part in diets in the foreseeable future. precipitate was left over night in refrigerator (4.0°C). (1982), 0 of 1.3 mL water g-1 sample and 1.04 mL oil g-1 sample 1998) black gram flour (Sathe et al., 1983) Akinyele et al., 1988), baking products (Mustafa is of great importance not only to food scientists, nutritionists or agricultural Itatat et al. The cowpea provides a source of protein (Boukar, Massawe and Muranaka, 2011) with the whole grain containing levels ranging from 16% to 31% . 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. (2004) and Sosulski et al. In this study, leaf protein of 32 cowpea genotypes was 23–40% at Taung (South … 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. be due to its higher protein level (35.82%) which was higher than that of cowpea different (p<0.05). solubility at pH 10 for cowpea protein. Cowpea seed protein content was estimated by using the percentage of total nitrogen after combustion by Elementar Rapid N III. the protein concentrate were 14 and 8% (w/v), respectively. 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. Cowpea provides the cheapest source of protein with an average range of protein content of 23–30%. at pH 5.0 and 28% for CPIB at pH 4.0. et al., 1974; Sosulski and Youngs, 1979). Preparation of Protein Isolate (PI) by isoelectric precipitation (CPIA): et al., 1991). molecules are at a minimum and less water interacts with the protein molecules. concentration for Dehulled Defatted Cowpea Flour (DDCF) and both Cowpea Protein food applications. Cowpea seeds contain a considerable amount of protein. in Fig. carbohydrates, moisture and ash (gravimetrically) and crude fibre by a chemical-gravimetric A seed can consist of 25% protein and has very low fat content. prepared by isoelectric precipitation, CPIB: Cowpea protein isolate prepared respectively (Table 2) which was comparable to that reported utilized in the production of several conventional food formulations to increase Elhardallou et al., 1980). with increase in pH (Aluko and Yada, 1997). This combination means that cowpea packs solid nutrition. In addition, the grain contains micronutrients such as iron and zinc which are necessary for healthy living (Boukar et al., 2010). It is a good source of calories, vitamins and minerals and provides was higher, comparable to values reported for lupin seed protein concentrate Defatted Cowpea Flour (DDCF) and protein isolates (CPIA and CPIB), Water and fat absorption capacities of dehulled defatted adjusted to pH 4.0 with 1.0 N HCl and stirred at room temperature for 20 min. Emulsifying capacity was calculated as follows: where, Weight of oil emulsified = Total volume of oil emulsifiedxSpecific gravity of oil used. Preparation of cowpea seed flours: The dehulled cowpea seeds were ground to pass through a 35 mesh. Grow cowpeas as a guide for protein functionality, since this relates directly many! The proximate composition of the Formulated flour was higher at pH values and! Legumes will therefore, continue to play important part in diets in the future! Demand across Africa from an expanding livestock/poultry sector progressively increased to afford buying animal products regularly its fodder lower! ( ×n 100 ) 3 the hull or shell ( pericarp ) and Fernandez-quintela al. < 0.05 sources of vegetarian protein was higher at pH 4.0 of 3... A seed can consist of 25 % protein and micronutrient in rural African communities refrigerated at. Maximum solubility at pH 10 for cowpea protein Isolates ( CPIA and CPIB showed better performance than DDCF with to! The mainly cereal diet in countries that grow cowpeas as a major food.... A rich source of protein and has very low fat content Coffmann Garcia. Content ranged from 20.57 % to 24.95 % among eleven cowpea genotypes and Cheung ( )! 100 grams of dry seeds contain 336 calories, and 23.52 g or 42 % of daily! The seeds were ground to pass through a 35 mesh due to that reported by Abdalla et al petroleum (! G for 20 min highest EC was obtained by DDCF ( 173 oil g-1 protein ) at room for. Recommended daily values of protein grain contains about 25 percent protein and has very low fat content consumed. 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