CULTIVAR, SPECIFIC-GRAVITY AND LOCATION IN TUBER AFFECT PUNCTURE FORCE OF RAW POTATOES

Three potato cultivars were sorted into specific gravity groups. Slices Of TaW potato were subjected to a puncture test at six sites in the cortex tissue and eight sites in the pith tissue. The cortex tissue generally showed 25-65% higher puncture force than the pith tissue. With exception of pith tissue in Monona cultivar, puncture force increased with increasing specific gravity in cortex and pith for raw potato. Dry matter content increased with increasing specific gravity. The cortex tissue had 3-6% higher dry matter than pith tissue.