Evaluation of glycoalkaloids in tubers of genetically modified virus Y-resistant potato plants (var. Désirée) by non-aqueous capillary electrophoresis coupled with electrospray ionization mass spectrometry (NACE–ESI–MS)

Abstract

The glycoalkaloid content of transgenic potatoes was evaluated by an optimised method based on non-aqueous capillary electrophoresis coupled on-line with electrospray ionization-mass spectrometry (NACE-ESI-MS). The potato material consisted of tubers from a conventional cv. Désirée and from three lines of modified plants resistant, intermediate and susceptible to infection by potato virus Y (PVY). The main glycoalkaloids were confirmed to be alpha-solanine and alpha-chaconine with parent ion masses m/z 852 and 868, respectively. In addition, an unknown minor peak at m/z 850.6 was found both in conventional (control) and susceptible line potato tubers. Such a compound exhibited an MS(2) spectrum with fragments ions at 704 and 396 m/z derived by loss of two ions, i.e. m/z 146 and 307, most likely corresponding to a rhamnose unit and a [glucose-(rhamnose)(2)] moiety, respectively. Up to 30-80-fold higher concentrations of total glycoalkaloids were found in the peel compared to flesh samples of all tubers examined. TGA content was nearly doubled in peel samples of resistant compared to control lines, and these levels were lower than the limit recommended for food safety, i.e. 20-60 mg of TGA per 100 g fresh weight. Moreover, it was established that tubers produced by virus-resistant clones are substantially equivalent in glycoalkaloid contents to those produced by conventional potato varieties.

Recent advances in the application of capillary electromigration methods for food analysis

“…Apart of the applications described above, CE methods have also been used to analyze other different compounds in foods [163][164][165][166][167][168][169][170][171][172][173][174]. Thus, capillary electromigration methods have successfully been applied for the simultaneous determination of multiple constituents in real beer samples [163,164].…”

“…The glycoalkaloid content of transgenic potatoes was evaluated by Biano et al [166] using an optimized method based on nonaqueous CE coupled on-line with electrospray ionization-mass spectrometry. The potato samples consisted of tubers from three lines of modified plants (i.e.,…”

“…Moreover, it was established that tubers produced by virus-resistant clones are substantially equivalent in glycoalkaloid contents to those produced by conventional potato varieties [166].…”

Overview on advances in capillary electrophoresis‐mass spectrometry of carbohydrates: A tabulated review

“…When applied to potatoes extracts, this method detected a-chaconine and a-solanine while no presence of solanidine was noticed, as expected, since the aglycons are normally not present in potatoes. The same authors also investigated the glycoalkaloids contents of some transgenic potatoes; there were no substantial differences between conventional and modified tubers [56].…”

“…To date, the main articles regarding the CE-MS of saccharidic compounds found in literature include the analysis of (i) standard mixtures [42,[47][48][49][50][51][52]; (ii) carbohydrates in nutrition [19,[53][54][55][56][57][58][59]; (iii) glycans from glycoproteins [60][61][62][63][64][65]; (iv) carbohydrates in drug development [45,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81].…”