Total glycoalkaloids and chlorophyll in potato cultivars bred in New Zealand

Abstract

Mature tubers of the potato cultivars bred at Crop Research Division, DSIR, were assayed for total glycoalkaloid (TGA) content before and after exposure to light, and for chlorophyll content after exposure to light. Tubers were assayed soon after harvest and after storage for 2 and 4 months at 10°c. Although recoveries were somewhat variable, TGA content was generally low but was increased by exposure to light; the levels also increased slightly during storage and the longer tubers were stored the less the increase in response to illumination. Ono was the only cultivar to exceed 20 mg TGA/100 g whole tuber when exposed to light. Differences in chlorophyll accumulation were found, and cultivars which contained high chlorophyll levels were not necessarily those which accumulated most TGA. Chlorophyll accumulation after exposure to light was also less in stored tubers.