Contents and its change during storage of α-solanine and α-chaconine in potatoes

Abstract

Contents of α-solanine and α-chaconine in native species of potato (May Queen, Danshaku and Waseshiro), and in species (Jagakids Red '90 (Red) and Jagakids Purple '90 (Purple)) on the market, and their change during storage at room temparature were investigated. α-Solanine and α-chaconine were extracted from potatoes with methanol, cleaned up by using a Sep-Pak Plus C18 cartridge, and then subjected to HPLC. The recoveries of α-solanine and α-chaconine from potatoes were both more than 96%, and the quantitation limits were both 2 μg/g. α-Solanine and α-chaconine were detected in periderm in all samples at the levels of 260-320 μg/g in May Queen, 190-240 μg/g in Danshaku, 43-63 μg/g in Waseshiro, 140-200 μg/g in Red and 84-130 μg/g in Purple, respectively. α-Solanine and α-chaconine were detected in the cortex in all samples of May Queen and Danshaku at the levels of 2.7-12 μg/g and 5.8-31 μg/g, respectively. Contents of α-solanine and α-chaconine in the cortex of May Queen and Danshaku were less than 10% of those in the periderm. When potatoes were stored for 90 days at room temparature in a dark place, no marked change in the contents of α-solanine and α-chaconine was observed in any of the potato samples.