Glycoalkaloid, phenolic, and flavonoid content and antioxidative activities of conventional nonorganic and organic potato peel powders from commercial gold, red, and Russet potatoes

Abstract Potato peels from the large-scale peeling of potatoes are a source of bioactive compounds. We determined the content of the glycoalkaloids α-chaconine and α-solanine, individual and total phenolics compounds, and total flavonoids extracted from three peels prepared from conventional and three from organic commercial gold, red, and Russet potatoes as well as determining their antioxidant activities using three different methods. Glycoalkaloids and individual phenolic compounds (caffeic acid, chlorogenic acid, and chlorogenic acid isomer) were determined using HPLC and LC–MS, and total phenolic and flavonoid content by colorimetry. There was a wide variation in the content of total glycoalkaloids, phenolic compounds, flavonoids, and antioxidative activities, as indicated by the following ratios for the total organic to nonorganic glycoalkaloids: gold, 3.89; Russet, 2.43; and red, 0.50. The corresponding phenolics and flavonoid ratios indicated a narrower range. The described methods could be used to determine the composition and antioxidative activities of peels derived from other potato cultivars, taking into account their methods of growth and postharvest storage, and aid in compositional, nutritional, medical, and industrial studies on potato peel, to relate their composition to their many described applications.