Changes of glycoalkaloids and nitrate contents in potatoes during chip processing

Changes in the glycoalkaloids, alpha-solanine and alpha-chaconine, and nitrate contents in potatoes of two varieties, Karlena - middle-early and Saturna - middle-late, were investigated during chip processing. The material for the study comprised samples from six stages of a chip production line. In the freeze-dried samples of potato and defatted chips obtained, the contents of a-solanine and alpha-chaconine were determined by HPLC and nitrates (NO3-) by reflectometer apparatus RQflex. Significant decrease of glycoalkaloids, particularly alpha-solanine, and nitrates contents during the process of chips production was observed. The ratio of alpha-chaconine to alpha-solanine contents during potato processing was maintained at a similar level during the whole process and was about 2.5:1. The highest amounts of glycoalkaloids were removed during peeling, slicing, washing and frying, and the highest amounts of nitrates during peeling and frying. (c) 2005 Elsevier Ltd. All rights reserved.