GLYCOALKALOID CONCENTRATION IN BY-PRODUCTS of POTATO STARCH EXTRACTION AS MEASURED BY MATRIX-ASSISTED LASER DESORPTIONIIONIZATION MASS SPECTROMETRY

Starch, potato protein concentrate, and potato pulp were produced in order to determine the fate of endogenous toxic glycoalkaloids during potato processing. Potato protein concentrate was precipitated from potato fruit water using acid and heat. Glycoalkaloid concentrations were determined using matrix- assisted laser desorption/ionization mass spectrometry. No correlation was observed between tuber protein concentration and yield of potato protein concentrate (r = 0.257). Glycoalkaloids could not be detected in starch extracted from tubers with a glycoalkaloid concentration of 6.6 mg/i 00 g (fwb). Dry potato protein concentrate and dry potato pulp produced from the same tubers contained 60 and 50 mg glycoalkaloid/100 g, respectively. the apparent partitioning of glycoalkaloids into the protein concentrate and pulp indicates toxicity might be a concern for these products, given that a maximum acceptable level of 20 mg glycoalkaloid/100 g is often cited for tubers.