Água-mel (honey–water) is a typical honey-based product produced by the Portuguese beekeepers, particularly in southern Portugal. Água-mel was characterized by mineral content and volatiles contents. Mineral content evaluation was performed based on a random sampling of 14 samples from a total of 16 samples provided by local producers. Mineral content showed that potassium predominated in água-mel samples (1270–4105 mg/kg). The concentration of aluminium in one sample was tenfold higher (5.8 mg/kg) than in the remaining samples (0.3–0.6 mg/kg). Água-mel volatiles were isolated by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) from a subset of eight samples. Cluster analysis showed two poorly correlated clusters (S cₒᵣᵣ < 0.3). Cluster I only sample was dominated by trans-β-ocimene (19 %), γ-terpinene (15 %) and 2-furfural (9 %). Cluster II that included the remaining seven samples showed two moderately correlated subclusters (S cₒᵣᵣ < 0.5). The six samples with high correlation from subcluster IIa were dominated by 2-furfural (18–41 %) and benzene acetaldehyde (12–39 %). n-Nonadecane (14 %), n-heneicosane and 2-furfural (both 13 %) were the main components of subcluster IIb sample. Although the presence of some volatile compounds can help in the correlation between água-mel and honey botanical source, the final product varies largely according to the preparation process even for the same producer, in different years. Água-mel detailed characterization may assist in bringing added value to this typical Portuguese honey-based product.

Se preparo un concentrado proteico integral (PCI) a partir de plantas de buchon de agua (Eichhornia crassipes) y se estudio su composicion quimica. El concentrado presento 46.2 por ciento de proteina, 8.6 por ciento de lipidos totales, 1.0 por ciento de fibra cruda, 30.3 por ciento de carbohidratos totales y un 11 por ciento de cenizas. Se determino Na (0.27 por ciento), Ca (2.22 por ciento), Mg (0.18 por ciento), K (3.03 por ciento) y P (0.67 por ciento); mientras que los elementos menores presentaron concentraciones de 40, 62, 189 y 855 ppm, para el Cu, Zn, Mg y Fe, respectivamente. Las propiedades nutricionales del concentrado se discuten en relacion con su composicion de aminoacidos y a su digestibilidad in vitro con enzimas proteoliticas. El contenido de aminoacidos esenciales del producto, comparado con los requerimientos para pollos en etapa de crecimiento, mostro llenar sus necesidades, excepto para metionina y cistina (1.8 y 1.2 contra 2.0 y 1.4 g/16 g N). El valor de la utilizacion de la proteina (UNP), encontrada para el CPI de buchon de agua, solo fue de 27.4 y 34.8 cuando fue suplementado con metionina y lisina. El analisis de factores antinutricionales no mostro cantidades detectables para aquellos de origen proteico como las lecitinas los inhibidores de tripsina, ni tampoco altos contenidos de taninos (4ppm). Sinembargo los niveles de fibra dietaria insoluble aparecen muy altos (20 por ciento)

Se estudio el efecto de la adicion de sal, disulfito de sodio y el b-mercaptoetanol sobre el proceso de fraccionamiento humedo de las proteinas del buchon de agua. Los resultados muestran que la coagulacion de las proteinas en forma de un concentrado proteico se logra mediante una accion conjunta del efecto salino y reductor que ejercen los compuestos adicionados al agua que se utiliza como medio de extraccion. Los mejores valores de extraccion y coagulacion se obtuvieron mezclando el material vegetal y el agua con 0.2 g/l (0.001 M) de disulfito de sodio en una relacion de 1:1 y adicionando acido clorhidrico hasta pH 3.0 al extracto obtenido. La metodologia final para la preparacion del CPI (concentrado proteico integral) de buchon de agua incluye el lavado del producto final con agua acidificada.

Bearing in mind that more than 50% of the land used for agriculture in Mexico is under semiarid and arid conditions, water availability and nutrition are among the main handicaps for crops to produce, particularly if they are fruit species. From the total area cultivated with apple, 36% is grown under rainfed conditions with a 4.2 t ha(-1) yield. Therefore, technology for improving nutrition with a more efficient use of available water is now being considered, in order to increase fruit yield and quality. This could lead to obtaining higher profits, and to being able to access more specialized systems in addition to ensuring a sustainable development. Growth, production, N, P, K, Ca, Mg, Mn, Cu, Fe, and Zn foliar concentration were determined in 'Agua Nueva II' apple trees, a low chilling mutant of 'Golden Delicious', grown in semiarid condition. Mulching (manure, grass residues, and bare soil as control), irrigation (flood irrigation and rainfall as control), and foliar fertilization (2.0 kg free biuret urea + 2.0 L Bayfolan + 200 mL surfactant ha(-1) sprayed twice a month, and control) treatments were studied. A split plot design with three randomized blocks was used for statistical analysis. Before applying the treatments in August 1997, the nutritional condition of the apple plants was established; Cu and Zn foliar concentration were deficient. Results in 1998 showed a general plant growth, production and nutritional condition improvement with some of the treatments. Flood irrigation significantly affected plant growth, as N, P, K, and Mn concentrations in leaves. Manure mulching also affected significantly plant growth and K concentration and caused the highest yields per tree. Zn concentration reached sufficiency levels, while Cu remained deficient.