ISHS Acta Horticulturae 1016: II International Conference on Postharvest and Quality Management of Horticultural Products of Interest for Tropical Regions
ESTIMATION OF THE DIOSCORIN EXTRACTED FROM CULTIVARS OF YAMS (DIOSCOREA GENUS) GROWING IN THE VENEZUELAN AMAZONAS -
|
| Authors: | E.E. Pérez, J. Faks, L.E. Cira, M. Schroeder, N. Diez |
| Keywords: | tubers, tuber proteins, storage proteins, Dioscorea japonica Palabras clave: tubérculos, proteínas de tubérculos, proteína de almacenamiento, Dioscorea japónica |
| DOI: | 10.17660/ActaHortic.2014.1016.5 |
| Abstract:
In the Venezuelan Amazonas are growing some cultivars yams with differing sizes and colors, that have not been yet completely identified. This yams could have some content of the water-soluble protein called dioscorin; which has been reported in yams (Dioscorea spp.), and that it have also been pointed out as an antioxidant. The aim of this study were to quantify the crude protein of yams of the Dioscorea genus that were harvested in the Venezuelan Amazon, to estimate the dioscorin protein by mass spectrometry, and to match this data with a significant database. The protein from the edible portion of each yam was extracted with different solvents and the protein concentration was measured by the methods of Kjeldahl, Lowry, and Bradford. The water extracts were separated using electrophoresis in a sodium dodecyl sulfate polyacrylamide gel. The identification of the induced and repressed proteins was carried out by MALDI-TOF MS PMF by using the bands of interest. The results reflected differences in the protein contents of the different fractions. Single bands of 32 kDa of proteins were obtained by electrophoresis when the water-soluble extract of each yam was assayed and the presence of dioscorin was estimated. By analyzing the results from the characteristic fingerprint obtained by MALDI-TOF MS FPP, it was concluded that the white yam is Dioscorea japonica. However, the number and intensity or the intensity only of the fragment ions obtained by MS for the other threes yams were insufficient for a significant identification. Resumen: En el Amazonas venezolano crecen variedades de ñames (Dioscorea spp.) que difieren en dimensiones y colores. Estos ñame podrían contener dioscorina, una proteína soluble en agua, reportada en ñames que es considerada como antioxidante. Los objetivos de este estudio fueron cuantificar el contenido de proteína de cinco ñames del género Dioscorea cosechados en el Amazonas venezolano, estimar el contenido de la proteína dioscorina por espectrometría de masa y comparar esta data con una importante base de datos. El contenido de proteína de la parte comestible de cada ñame se extrajo con diferentes solventes y la concentración de proteína se cuantificó por los métodos de Kjeldahl, Lowry y Bradford. Los extractos de agua fueron separados mediante electroforesis en gel de poliacrilamida de sodio-dodecil-sulfato. Se realizó la identificación de las proteínas inducidas y reprimidas por MALDI-TOF MS PMF utilizando las bandas de interés. Los resultados reflejan diferencias en el contenido de proteína de las diferentes fracciones. En el extracto soluble en agua de cada ñame se estimó la presencia de dioscorina; ya que se reportaron solo bandas de 32 kDa de proteínas por electroforesis. Analizando los resultados de la huella característica obtenida por MALDI-TOF MS FPP, podría concluirse que el ñame blanco es Dioscorea japónica. Sin embargo, el número y la intensidad o la intensidad solo de los iones del fragmento obtenido por MS para los otros tres ñames eran insuficientes para una identificación significativa. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
