ABSTRACT
El contenido mineral de la miel producida en cinco zonas de del estado Zulia, Venezuela , durante las estaciones de sequía y de lluvia, fue determinado. Los elementos analizados en las muestras de miel cruda, recogidas directamente de varios apicultores fueron: sodio, potasio (por espectroscopía de emisión) calcio, magnesio, cobre, hierro, manganeso (por espectroscopía de absorción atómica), fósforo (iones de fosfato, determinado por colorimetría). Los valores promedios para el Na, K, Ca, Mg, Cu, Fe, Mn y P fueron: 353+84; 1774+138; 237+66; 52+24; 0,76+0,43; 13,5+10,23; 0,92+0,42 y 1642+323 mg/kg respectivamente. El contenido promedio de cenizas fue de 0,431+0,15 por ciento. El contenido de potasio fue el mas abundante de los elementos determinados. Estos resultados confirman que las mieles producidas en el estado Zulia pueden ser consideradas una buena fuente de minerales
Subject(s)
Spectrophotometry, Atomic , Honey , Minerals , Nutritional Sciences , VenezuelaABSTRACT
The mineral content of the honey produced in five zones of the Zulia state, Venezuela, during dry and rainy seasons was determined. The analyzed elements were: sodium, potassium (by emission spectroscopy), calcium, magnesium, copper, iron, manganese (by atomic absorption spectroscopy), phosphorus (phosphate ions, by colorimetric method), and ash content of raw honey samples directly collected from different beekeepers. The mean values for Na, K, Ca, Mg, Cu, Fe, Mn, and P were 353+84; 1774+138; 237+66; 52+24; 0.76+0.43; 13.5+10.23; 0.92+0.42 and 1642+323 mg/kg respectively. The mean ash content was 0.431+0.15%. Potassium was the most abundant of the elements determined. This results confirm that Zulian honey can be considered a good source of minerals.
Subject(s)
Honey/analysis , Minerals/isolation & purification , Animals , Colorimetry/methods , Phosphorus/isolation & purification , Potassium/isolation & purification , Sodium/isolation & purification , Spectrophotometry, Atomic , VenezuelaABSTRACT
Xylanase production of Trichoderma reesei Rut C-30 was examined at different initial pH values (4.8, 5.9, and 7.0) on rice straw in shake flasks, and in a fermentor, for the best pH condition. Enzyme performance was tested on ammonia-treated dwarf elephant grass. The maximum xylanase activities, 92 and 122 IU/mL, were obtained at pH 4.8 in the shake flasks and fermentor, respectively, in which good growth of the fungus was observed during the first 24 h and consumption of proteins dissolved from the rice straw caused the pH to rise later to values between 6.4 and 6.7 (optimal for xylanase production). The xylanases from T. reesei were as effective as Multifect XL, a commercial enzyme preparation, in hydrolyzing ammonia-treated elephant grass.
Subject(s)
Oryza/microbiology , Trichoderma/enzymology , Xylosidases/biosynthesis , Cellulase/metabolism , Fermentation , Hydrogen-Ion Concentration , Hydrolysis , Kinetics , Trichoderma/growth & development , Xylan Endo-1,3-beta-XylosidaseABSTRACT
Rice straw pretreated with liquid anhydrous ammonia was hydrolyzed with cellulase, cellobiase, and hemicellulase. Ammonia-processing conditions were 1.5 g of NH3/g of dry matter, 85 degrees C, and several sample moisture contents. There were four ammonia addition time (min)-processing time (min) combinations. Sugars produced were analyzed as reducing sugars (dinitrosalicylic acid method) and by high-performance liquid chromatography. Monomeric sugars increased from 11% in the nontreated rice straw to 61% of theoretical in treated rice straw (79.2% conversion as reducing sugars). Production of monosaccharides was greater at higher moisture content and was processing time dependent. Glucose was the monosaccharide produced in greater amounts, 56.0%, followed by xylose, arabinose, and fructose, with 35.8, 6.6, and 1.4%, respectively.
