Effect of tuber size on failure properties of potato tissue

Larger tubers are known to be more impact sensitive than smaller tubers for a given drop height. This is generally thought to be due to the higher kin etic energy the larger tubers have during impact. The goal of this work was to determine if the tuber size affects the fundamental failure properties of potato tuber tissue. A better understanding of whether tuber size affect s these properties will help in determining future sampling techniques, by eliminating tuber size as a confounding factor Russet Burbank and Atlantic cultivars weighing between 113 to 454 g (4-16 oz) representing size ranges commonly encountered in handling situations were used. Tissue samples from the stem ends of these tubers were tested to failure using dynamic axial co mpression (strain rate = 80 s(-1)) at a temperature of 8 degrees C. The res ults show that while tubers over 340 g are significantly less tough than th ose under 170 g, tubers between 170 and 340 g (6-12 oz) do not have signifi cantly different failure properties (failure stress, failure strain and sho ck wave speed). Thus tuber sampling for tests of such properties can use tu bers in the 170 to 340 g range without significant effects of tuber size.