Epsilon Archive for Student Projects

Abstract

Glycoalkaloids are secondary metabolites found in several plant species of the Solanaceae family. In cultivated potatoes, chaconine and solanine account for 95% of the glycoalkaloid content. Glycoalkaloids can cause toxic conditions in humans and animals at levels around 1 mg/kg body weight. There is a desire among starch producing companies to develop potato varieties with both high levels of starch and low levels of glycoalkaloids. If this could be achieved, the leftovers from the starch production, that now contains too high levels of glycoalkaloids, could instead be used for animal feed. The purpose of this study is to see how glycoalkaloids and starch segregate into a cross between food potatoes and starch potatoes.
A method was developed which enabled fast analysis of glycoalkaloid levels from leaves and tubers. The method used extraction with acid, separation on solid phase column, and detection with Dragendorff’s reagent. The glycoalkaloid levels were analysed in leaves of 140 offsprings from a cross between a table potato and starch potato. The glycoalkaloid levels were also analysed in tubers for ten of these 140 offsprings. Starch levels were measured in some of the tubers by measuring the dry matter. A large variation in glycoalkaloid levels was observed in the leaves. A similar variation was observed also in the tubers. In addition, it was noticed that the starch levels varied between different tubers. It appeared that some hybrids had both high starch levels and low glycoalkaloid levels. Further research is needed for final development of a potato variety with traits requested by the starch industry.