Improvement of the Protein Quality of Corn With Soybean Protein
In most Central American countries, lime-treated corn provides 31% of the total protein and 45% of the energy intake, and beans 24% of the protein and 12% of the calories. Such diet is low in protein quality and quantity, as well as in energy. To overcome these deficiencies, corn can be supplemented either with its limiting amino acids, lysine and tryptophan, or, better still, with whole soybeans which improve not only the amount and quality of the protein consumed but, because of their high oil content, the energy intake as well. In addition, animal experiments have shown that for maximum utilization of these nutrients, adequate vitamin and mineral intake is indispensable.
At a level of 15 parts of whole soybean or 8 parts soybean-derived products, to 85–92 parts of corn there were no significant changes in the rheological or organoleptic characteristics of the tortilla prepared there of. Higher levels of soybean products, however, may affect the consistency of the lime-treated corn dough and, therefore, the tortilla acceptability. Since corn is usually cooked, but not ground, at home, the soybean supplement can be successfully added at the wet-milling stage of dough preparation or whole soybeans and corn may be cooked together, when a nutritional intervention is desired at the village level. At an industrial scale, if whole soybeans are used, they may be cooked together with corn, and if soy flour is used, this can be mixed at the end of the process when the cooked corn is ground to a flour.
A flow diagram for supplementing corn with 15% whole soybeans is presented. If interventions of this nature are to be successful, there is need for increasing the prestige of corn-based foods, as well as of nutrition education programs in these populations.
KeywordsProtein Quality Nitrogen Balance Soybean Protein Nitrogen Solubility Protein Efficiency Ratio
Unable to display preview. Download preview PDF.
- Bressani, R. (1971). Amino acid supplementation of cereal grain flours tested in children. In,‘Amino acid fortification of Protein Foods’, N. S. Scrimshaw and A. M. Altschul (Editors). Report of an International Conference Massachusetts Institute of Technology (MIT), Cambridge, Mass., 1969. The MIT Press. p 184–204.Google Scholar
- Bressani, R., Elias, L. G., Molina, M. R. and Rubio, M. (1977). Further studies on the enrichment of lime-treated corn with soybean protein. 37th Annual Meeting of the Institute of Food Technologists. Philadelphia, Pensylvania, June 6–9.Google Scholar
- Bressani, R., Marenco, E. (1963). The enrichment of lime-treated corn flour with proteins, lysine and tryptophan, and vitamins. J. Ag. Food Chem. 6, 517–522.Google Scholar
- Bressani, R., Murillo, B. and Elias, L. G. (1974). Whole soybeans as a means of increasing protein and calories in maize-based diets. J. Food Sci. 39, 577–580.Google Scholar
- Elias, L. G. and Bressani, R. (1972). Nutritional value of the protein of tortilla flour and its improvement by fortification in Central America. In, ‘Nutrition al Improvement of Maize’, R. Bressani, J. E. Braham and M. Béhar (Editors). Proceedings of an International Conference held at the Institute of Nutrition of Central America and Panama (INCAP), Guatemala City, March 6–8, 1972. Talleres Grâficos del INCAP. p. 168–190.Google Scholar
- Molina, M. R., Elias, L. G., G6mez Brenes, R. A., Lachan ce, P. A. (1972). The technology of maize fortification in Latin America. In, ‘Nutritional Improvement of Maize’, R. Bressani, J. E. Braham and M. Béhar (Editors). ‘Proceedings of an International Conference held at the Institute of Nutrition of Central America and Panama (INCAP), Guatemala City, March 6–8, 1972. Talleres Grâficos del INCAP. p 235–255.Google Scholar
- Murillo, B., Cabezas, M. T. and Bressani, R. (1974). Influencia de la densidad calbrica sobre la utilizacibn de la proteîna en dietas elaboradas a base de maiz y frijol. Arch. Latinoamer. Nutr. 24, 223–241.Google Scholar
- Sauberlich, H. E., Chang, W. Y. and Salmon, W. D. (1953). The comparative nutritive value of corn of high and low protein content for growth in the rat and chick. J. Nutr. 51, 623–635.Google Scholar
- Sure, B. (1953). Protein efficiency: Improvement in whole yellow corn with lysine, tryptophan and threonine. J. Ag. Food Chem. 1, 626–629.Google Scholar
- Urrutia, J. J., Garcia, B., Mata, L. J. and Bressani, R. (1975). Reporte preliminar del efecto biol6gico de la fortificaciôn del maiz con harina de soya y lisina. En, ‘Memorias–Primera Conferencia Latinoamericana sobre la Proteina de Soya’. Asociaci6n Americana de Soya. México, D. F. Nov. 9–12. p. 134–145.Google Scholar
- Viteri, F. E., Martinez, C. and Bressani, R. (1972). Evaluation of the protein quality of common maize, Opaque-2 maize and common maize supplemented with amino acids and other sources of protein. In, ‘Nutritional Improvement of Maize’.Google Scholar
- R. Bressani, J. E. Braham and M. Béhar (Editors). Proceedings of an International Conference held at the Institute of Nutrition of Central America and panama (INCAP), Guatemala City, March 6–8, 1972. Talleres Grâficos del INCAP. p. 191–204.Google Scholar