Isolation and characterization of functional components from peel samples of six potatoes varieties growing in Ontario

Potato processing industry generates high amounts of peel as a byproduct. It is a good source of several beneficial functional ingredients including antioxidant polyphenols. A study was undertaken to estimate the polyphenolic content and antioxidant properties of peel samples from potatoes grown in Ontario, Canada. Peel samples from Vivaldi, Yukon Gold, Dakota Pearl, FL 1533, Siècle and Purple Majesty varieties of potatoes were extracted with methanol and analyzed for their polyphenolic contents and antioxidant properties using Folin–Ciocalteu reagent, ferric-ion reducing antioxidant power (FRAP), Trolox equivalent (6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid) and free radical scavenging activity (FRSA). Specific phenolic compounds present in potato peel samples were measured using HPLC. Results of total phenolic compounds from both spectrophotometric and chromatographic analyses were statistically compared to validate methods of extraction and determination. Red-colored potato varieties; Siècle and Purple Majesty, had the highest antioxidant potential compared to other varieties. Chromatographic data showed differences in the amounts, but not in types of phenolic compounds in the potato peel samples.