Comparison of two methods for determining the discoloration potential of potato tubers based on their chemical and biochemical properties

Abstract

The aim of this study was to compare the homogenization and visual methods that are used to determine the discoloration potential of potato tubers. Two German cultivars, Agria and Satina, and two Polish cultivars, Lena and Mors, were planted during 1998 and 1999 in Goettingen, Germany, and in Bydgoszcz, Poland. The discoloration potential of the tubers was measured after harvesting and after 6 months of storage at 4 C and 8 C. Both methods correlated significantly at harvest (0.709, P < 0.001). After storage the correlation was significant but low (r = 0.403, P < 0.001) probably because of physical changes in the tuber during storage. The visual method can be used as a fast method, especially at harvest. However, the homogenization and visual methods determine, to a certain degree, different tuber properties leading to the discoloration potential. Therefore, a complete comparison is not possible. The methods studied in this paper can complement but not substitute each other. Reliable comparisons between institutes require use of the same method to determine the discoloration potential of the tuber.