Chemical and physical properties of potatoes differing in bruise susceptibility

Chemical and physical properties of five cultivar potatoes were measured in order to explain the varietal differences in blackspot susceptibility. Bruise-resistant potatoes had lower polyphenol content and polyphenol oxidase activity, and higher failure stresses of both skin and underlying tissues than susceptible ones. In addition, there was a significant (p<0.05) relationship between bruise scores and skin failure stresses and it directly implied that the measurement of skin failure stress using a plunger is a useful method for screening potato varieties for blackspot susceptibility because of the ease of measurement.