Abstract
A new method for determining total glycoalkaloid content of potatoes (TGA) was developed by extensively modifying the comprehensive titration procedure of Fitzpatrick and Osman (1). This modified titration method eliminates the need to hydrolyze the glycoalkaloids and to purify the resulting aglycones by partitioning them into an organic solvent such as benzene or methylene chloride. Instead the glycoalkaloids are precipitated using ammonium hydroxide with the precipitate being dissolved in a tetrahydrofuran-water-acetonitrile (50:30:20) mixture. An aliquot is evaporated and quantitated using the nonaqueous titration procedure developed by Fitzpatrick and Osman (1). A comparison between this modified method and a high-performance liquid Chromatographic (HPLC) procedure was made using three commercial potato varieties and five experimental selections. Results from the two methods compared favorably.
Resumen
Un nuevo método para determinar contendo total de glicoalcaloides en papas (TGA) fué desarrollado modificando extensamente el procedimiento de titulación de Fitzpatrick y Osman. Este método modificado elimina la necesidad de hidrolizar los glicoalcaloides y de purificar los aglicones resultantes separándolos en un solvente orgánico como benceno o cloruro de metileno. En su lugar, los glicoalcaloides fueron precipitados usando hidróxido de amino, siendo el precipitado disuelto en una mexcla 50:30:20 de tetrahidrofuran — agua y acetonitrilo. Una alicuota fué evaporada, y cuantificada usando el procedimiento de titulación orgánica desarrollado por Fitzpatrick y Osman (1). Un comparativo entre este método modificado y un procedimiento de Cromatografía Líquida de Alta Eficacia (HPLC) fué hecho, utilizando tres variedades comerciales de papa y 5 selecciones experimentales. Los resultados de los métodos compararon favorablemente.
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Bushway, R.J., Wilson, A.M. & Bushway, A.A. Determination of total glycoalkaloids in potato tubers using a modified titration method. American Potato Journal 57, 561–565 (1980). https://doi.org/10.1007/BF02854157
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DOI: https://doi.org/10.1007/BF02854157