RESUMO
A better knowledge of the amino acid composition of foods commonly consumed in different regions is essential to calculate their scores and, therefore, to predict their protein quality. This paper presents the amino acid composition, amino acid score and in vitro protein digestibility of fifteen foods that are commonly consumed in Northwest Mexico. The foods were prepared by the traditional methods and were analyzed by reverse-phase HPLC. The chemical score for each food was determined using the recommendations for children of 1-2 years of age, and the digestibility was evaluated using a multienzyme technique. Lysine was the limiting amino acid in cereal-based products (scores 15 to 54), and methionine and cysteine were limiting in legume products (scores 41 to 47), boiled beef (score = 75) and hamburger (score = 82). The method of preparation had an effect on the content of certain amino acids, some of them increased and others decreased their content. Meat products and regional cheese provided a high amino acid score (scores 67 to 91) and digestibility (80.7 to 87.8%). Bologna, a processed meat product, had a lower digestibility (75.4%). Data on the amino acid composition of foods commonly consumed in Mexico can be used to provide valuable information on food analysis and protein quality, and to contribute to nutrition and health research and health programs.
El conocimiento adecuado de la composición de aminoácidos en los alimentos consumidos frecuentemente en las diferentes regiones, es esencial para calcular la calificación de aminoácidos y predecir la calidad proteica de dichos alimentos. Este manuscrito presenta la composición y calificación de aminoácidos, así como la digestibilidad de proteína in vitro de quince alimentos consumidos frecuentemente en el noroeste de México. Los alimentos se prepararon por los métodos tradicionales y se analizaron por cromatografía de líquidos de alta resolución en fase reversa. La calificación química para cada alimento se determinó utilizando las recomendaciones para niños de 1-2 AÑOs de edad, y la digestibilidad se evaluó utilizando un método multienzimático. La lisina fue el aminoácido limitante en los productos a base de cereales (calificación 15 a 54), y metionina y cisteína fueron limitantes en las leguminosas (calificación 41 a 47), carne cocida (calificación 75) y hamburguesa (calificación 82). El método de preparación tuvo un efecto en el contenido de ciertos aminoácidos, algunos de éstos aumentaron y otros disminuyeron su contenido. Los productos cárnicos y el queso regional tuvieron una calificación de aminoácidos (calificación 67 a 91) y digestibilidad (80,7 a 87,8%) elevadas. La bolonia, que es un producto cárnico procesado, tuvo la digestibilidad más baja (75,4%). Los datos de la composición de aminoácidos en alimentos consumidos frecuentemente en México pueden utilizarse para el análisis de alimentos y evaluación de su calidad proteica, y contribuir a la investigación en nutrición y salud.
Assuntos
Aminoácidos/análise , Proteínas Alimentares/análise , Proteínas Alimentares/metabolismo , Queijo/análise , Cromatografia Líquida de Alta Pressão , Digestão , Grão Comestível/química , Fabaceae/química , Humanos , Hidrólise , Carne/análise , México , Valor Nutritivo , Espectrometria de FluorescênciaRESUMO
Vitamin A (VA) deficiency (VAD) continues to be a major nutritional problem in developing countries, including Central America. In Mexico, milk is a well-accepted vehicle for the administration of micronutrients, including VA, to preschoolers. Thus, we conducted a randomized, controlled, clinical trial to investigate the efficacy of daily consumption of 250 mL of VA-fortified milk (which provided 196 retinol equivalents/d) for 3 mo on VA stores in mildly to moderately VAD (serum retinol concentration 0.35-0.7 µmol/L) preschoolers who were not enrolled in a food assistance program. Twenty-seven mildly to moderately VAD children were randomly assigned based on screening measurements to either the intervention (n = 14) or control group (n = 13) (children in the control group did not receive placebo). All children in the control group and 79% (n = 11) of the children in the intervention group completed the study. The total body VA (TBVA) pool size was estimated using the deuterated retinol dilution technique before and after the intervention. After 3 mo, median changes in the serum retinol concentration for the intervention and control groups were 0.13 and -0.21 µmol/L, respectively (P = 0.009). Median changes in the TBVA stores were 0.06 and 0.01 mmol, respectively (P = 0.006) and estimated median changes in the liver VA concentration were 0.09 and 0.01 µmol/g, respectively (P = 0.002). The VA-fortified milk was well accepted among preschoolers and significantly increased TBVA stores, liver VA stores, and serum retinol concentration, indicating that it may be an effective means to ameliorate VAD in young Mexican children.