Effect of antiviral genetical modification on softening of potato tubers during cooking

Abstract

An investigation into the influence of genetical modification on potato tubers should include also an estimation of their technological usability. Potato tubers of 15 clones of cultivar Irga transformed with viral genome sequences in order to improve their resistance to a necrotic strain of potato virus Y (PVYN) were examined. The effect of cooking on tissue texture, expressed by fracture stress (F) and strain (D), and elastic modulus (E) from a compression test, was investigated. Although the influence of the modification type appeared to be statistically significant but irregular in particular years of cultivation, a detailed statistical analysis (variance and discrimination analyses) did not confirm any repeatable nor statistically significant differences in F, D, and E over the three-years period of examinations. While the effect of cultivation year was unmistakable, the order of F, D, and E values for particular clones was not constant in the successive years. The lack of stable tendencies in average values of the mechanical parameters for both groups and subgroups of clones representing the same modification model was also found. The statistical analysis of the variability of mechanical parameters of raw and heat-treated potatoes measured during the three successive years enabled classifying Irga and its genetically-modified clones as similar and did not allow to distinguish clones of the quickest softening.