Effect of repetitive impacts on subcutaneous tissue discolouration in potato tubers

Abstract

The relation between one or more impacts at one tuber site and the resulting volume and depth of discoloured tissue were investigated. Tubers were impacted at the desired rate by a computer-controlled pendulum. The tubers were from plants grown at 2 potassium levels (i.e. susceptibilities to tissue discoloration - high and low) and stored for 3, 5 or 7 months. Splitting of the impact energy into various (up to 9) doses reduced the volume of discoloured tissue by up to 64%. The depth of tissue damage was less affected (33% reduction) by splitting the impact energy than was the volume. The volume and depth of discoloured tissue increased with the number of 0.3 J impacts. A decreasing and an increasing order of impact energy caused the same tissue damage. Despite experimental simplification and standardization, the observed effects of the energy and frequency of impacts on the degree of subcutaneous tissue discoloration yielded relevant suggestions for practical potato handling.