RESUMO
Se analizaron características morfológicas relacionadas con el fruto, espinas, endocarpio y semilla, así como parámetros fisicoquímicos y nutricionales (humedad, proteínas, ºBrix, fibra alimentaria, cenizas, pH, acidez, ácido ascórbico, compuestos fenólicos totales, minerales: Na, K, Ca y Mg y elementos traza: Fe, Cu, Zn y Mn), en muestras de chayota (Sechium edule) pertenecientes a 7 entradas cultivadas en las islas de Tenerife y La Palma (España) y cosechadas durante el período comprendido entre junio y noviembre de 2005. Se observaron diferencias importantes en la composición química y características morfológicas entre las diferentes entradas de chayota estudiadas. La entrada 4 destacó por su alto contenido en minerales y sólidos solubles totales (ºBrix) y bajo contenido en agua, mientras que la entrada 1 presentó altos contenidos en Na, cenizas y ácido ascórbico. El contenido de humedad y de ácido ascórbico varió en función de la parte del fruto analizada, sin embargo, los contenidos de compuestos fenólicos y de cenizas no fueron dependientes de las partes. La fecha de muestreo mostró una gran influencia sobre la composición química, observándose las mayores diferencias en las muestras cosechadas en el mes otoñal de noviembre respecto a las restantes cosechadas en meses estivales. El análisis discriminante permitió diferenciar las muestras de chayota en función de la entrada y fecha de muestreo, por lo que es una herramienta muy útil para la caracterización de muestras(AU)
Morphological and chemical composition characterization of chayotas (Sechium edule) grown in the Canary Islands (Spain). Morphological characteristics related to the fruit, thorns, endocarp and seed, as well as physicochemical and nutritional parameters (moisture, protein, ºBrix, fiber, ash, pH, acidity, ascorbic acid, total phenolics, minerals: Na, K, Ca and Mg, and trace elements: Fe, Cu, Zn and Mn) were analyzed in samples of chayote (Sechium edule) belonging to 7 accessions grown on the islands of Tenerife and La Palma (Spain) and harvested during the period between June and November 2005. Significant differences in chemical composition and morphology between the chayote accessions studied were observed. The accession 4 features a high mineral content and soluble solids (Brix degree) and low water content, while the accession 1 had high contents of Na, ash and ascorbic acid. The moisture content and ascorbic acid varied depending on the portion of the fruit analyzed, however, the contents of phenolic compounds and ash were not affected. The sampling date showed a great influence on the chemical composition, the greatest differences observed in the samples harvested in the month of November autumn, with respect to the remaining summer months. Discriminant analysis allowed differentiate samples chayota according to the accession and sampling date, so it is a very useful tool for the characterization of these samples(AU)
Assuntos
Ácido Ascórbico , Fenômenos Químicos , Citrus/metabolismo , Compostos Fenólicos , Minerais/análise , Plantas , Fibras na Dieta , FrutasRESUMO
Concentrations of calcium, magnesium, sodium and potassium were determined in 55 samples of mature human milk from Canary women and 5 samples of powdered infant formula. According to the literature our data fell within the normal intervals described for each kind of milk. The mean concentration of Ca, Mg, Na y K of powdered infant formula was higher than those concentrations found in the human milks. Significant differences among the concentrations of Ca, Mg and Na for the milks of the considered mothers were observed. Only the Ca intakes for infants fed with human milk were lower than those requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had an adequate intake of all the studied metals. A progressive decrease of the Na, K and Ca concentrations with the lactation stage was observed. Maternal age, parity and sex of the newborns did not affect the metal concentrations significantly.