Amino Acid Composition of Cowpea (Vigna ungiculata L. Walp) Flour and Its Protein Isolates


The study of the nutritive value of Cowpea (Vigna ungiculata L.) legume seed is needed, as this legume is a food source in many developing countries. Whole Cowpea Flour (WCF), Dehulled Defatted Cowpea Flour (DDCF), and Cowpea Protein Isolates (CPI) prepared using Isoelectric method (CPII) and using Micellization method (CPIM) are studied. In proximate analysis, the protein content of WCF, DDCF, CPIA and CPIB was found to be 22.3, 26.7, 750 and 76.0 g/100 g, respectively. Net protein value (NPV) was 17.62 for DDCF. Chemical score was 0.66% for DDCF and 112%, 104% for CPII and CPIM, respectively. The first limiting amino acid was cystine for DDCF and threonine for CPII and CPIM. Methionine was found to be the most concentrated essential amino acid in both CPII and CPIM; values were 27.22 and 30.60 g/16 g N, respectively, while lysine was the most abundant essential amino acid in DDCF (4.28 g/16 g N). Essential amino acids of CPIi and CPIM were 22.99 and 15.78 g/16 g N respectively, higher than FAO/WHO reference.

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Elharadallou, S. , Khalid, I. , Gobouri, A. and Abdel-Hafez, S. (2015) Amino Acid Composition of Cowpea (Vigna ungiculata L. Walp) Flour and Its Protein Isolates. Food and Nutrition Sciences, 6, 790-797. doi: 10.4236/fns.2015.69082.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Rochfort, S. and Panozzo, J. (2007) Phytochemicals for Health, the Role of Pulses. Journal of Agricultural and Food Chemistry, 55, 7981-7994.
[2] Pastor-Cavada, E., Juan, R., Pastor, J.E., Alaiz, M. and Vioque, J. (2009) Analytical Nutritional Characteristics of Seed Proteins in Six Wild Lupinus Species from Southern Spain. Food Chemistry, 117, 466-469.
[3] Frieddman, M. (1996) Nutritional Value of Proteins from Different Food Sources. A Review. Journal of Agriculture Food Chemistry, 44, 6-29.
[4] Taiwo, K.A. (1998) The Potential of Cowpea as Human Food in Nigeria. Technovation, 18, 469-481.
[5] Chavan, J.K., Kadam, S.S. and Salunkhe, D.K. (1989) Cowpea in: Hand Book of World Food Legume: Nutritional Chemistry, Processing Technology and Utilization, Volume 2. Salunkhe and Kadam, Eds., CRC Press, Florida.
[6] Egouniety, M. and Aworh, O.C. (2003) Effect of Soaking, Dehulling, Cooking and Fermentation on the Oligosaccharides, Trypsin Inhibitors, Phytic Acid and Tannins of Soybean (Glysin max Merr.), Cowpea (Vigna ungiculata Walp) and Ground Bean (Mccrotyloma geocarpa Harms). Journal of Engineering, 56, 249-254.
[7] Evans, M. and Boulter, D. (1980) Crude Protein and Sulphur Amino Acids Contents of Some Commercial Varieties of Peas and Beans. Journal of Science Food Agriculture, 31, 238-242.
[8] Gwiazda, S., Schwenke, K.D. and Rutkowski, A. (1980) Isolation and Partial Characterization of Proteins from Pea (Pisum sativum L.). Nahrung, 24, 939-950.
[9] Duranti, M. and Gius, C. (1997) Legume Seeds: Protein Content and Nutritional Value. Field Crops Research, 53, 31- 45.
[10] Kachare, D.P., Chavan, J.K. and Kadam, S.S. (1987) Nutritional Quality of Some Improved Cultivars of Cowpea. Plants Food for Human Nutrition, 38, 155-162.
[11] Rangel, A., Saraiva, K., Schwengber, P., Narciso, M.S., Domont, G.B., Ferreira, S.T. and Pedrosa, C. (2003) Biological Evaluations of a Protein Isolate from Cowpea (Vigna ungiculata) Seeds. Food Chemistry, 87, 491-499.
[12] Kahl, J., Baars, T., Bügel, S., Busscher, N., Huber, M., Kusche, D., Rembialkowska, E., Schmid, O., Seidel, K., Taupier-Letage, B., Velimirov, A. and Zalecka, A. (2012) Organic Food Quality: A Framework for Concept, Definition and Evaluation from the European Perspective. Journal of the Science of Food and Agriculture, 92, 2760-2765.
[13] Seidel, K., Kahl, J., Paoletti, F., Birlouez, I., Busscher, N., Kretzschmar, U., S?rkk?-Tirkkonen, M., Selj?sen, R., Sinesio, F. and Torp, T. (2015) Quality Assessment of Baby Food Made of Different Pre-Processed Organic Raw Materials under Industrial Processing Conditions. Journal Food Science and Technology, 52, 803-812.
[14] McCurdy, S. and Kniptel, J. (1990) Investigation of Faba Bean Protein Recovery and Application to Pilot Scale Processing. Journal Food Science, 55, 1093-1094.
[15] Fernandez-Quintela, A., Maccrulla, M.T., Del-Barrio, A.S. and Martinez, J.A. (1997) Composition and Functional Properties of Protein Isolates Obtained from Commercial Legumes Grown in Northern Spain. Journal Plant Foods for Human Nutrition, 51, 331-342.
[16] Lampart-Szczapa, E., Obuchowski, W., Czaczyk, K., Pastuszewska, B. and Buraczewska, L. (1996) Effect of Lupin Flour on the Quality and Oligosaccharides of Pasta and Crisps. Nahrung/Food, 41, 219-223.
[17] Association of Official Analytical Chemists (1998) Official Method of Analysis. 16th Edition, AOAC, Washington DC.
[18] Moore, S., Spackman, D.H. and Stein, W.H. (1958) Chromatography of Amino Acid on Sulphonated Polystyrene Resins. An Improved System. Analytical Chemistry, 30, 1185-1190.
[19] Block, R.J. and Mitchell, H.H. (1946) The Correlation of the Amino Acid Composition of Proteins with Their Nutritive Value. Nutrition Abstracts & Reviews, 16, 249-278.
[20] FAO/WHO (1973) Energy and Protein Requirements. Report of a Joint FAO/WHO Adhoc Expert Committee. FAO Nutritional Meeting Report Series No. 52, Technical Report Series No. 522 Food and Agriculture Organization of the United Nation, Rome.
[21] Oser, B.L. (1959) An Integrated Essential Amino Acid Index for Predicting the Biological Value of Proteins. In: Albanese, A.A., Ed., Amino Acid Nutrition, Academic Press, New York, 295-311.
[22] Hidvegi, M. and Bekes, F. (1984) Mathematical Modeling of Protein Nutritional Quality from Amino Acid Composition. In: Lazity, R. and Hidvegi, M., Eds., Proceedings of the International Association for Cereal Chemistry Symposium, Academic Kiado, Budapest, 205-286.
[23] Alsmeyer, R.H., Cunningham, A.E. and Happich, M.L. (1974) Equations Predict PER from Amino Acid Analysis. Food Technology, 28, 34-38.
[24] Paradez-Lopez, O., Ordorica-Falomir, C. and Carabez-Trejo, A. (1988) Production of Safflower Protein Isolates: Physicochemical Characterization. Lebensmittel-Wissenschaft & Technologie, 21, 328-333.
[25] Murry, E.D., Myers, C.D. and Barker, L.D. (1981) Functional Attributes of Protein. A Non-Covalent Approach to Processing Ant Utilizing Plant Proteins. In: Stanley, D.W., Murray, E.D. and Lees, D.W., Eds., Utilization of Protein Resources, Food and Nutrition Press, Westport, 158.
[26] Arakawa, J. and Timasheff, S.N. (1982) Preferential Interactions of Proteins with Salts in Concentrated Solutions. Biochemistry, 21, 6545-6552.
[27] Olaofe, O. and Akintayo, E.T. (2000) Production of Isoeletric Points of Legume and Oil Seed Proteins from Amino Acid Composition. Journal Technology Science, 4, 49-53.

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