Screening the New Zealand potato germplasm collection for resistance to sugar accumulation during low temperature storage

Abstract

The ability of potato (Solanum tuberosum) cultivars to withstand cool storage without accumulating reducing sugars would allow manufacturers of fried potato products to process potatoes year-round without the development of undesirable Maillard browning compounds. More than 600 potato cultivars and selections held by the New Zealand Institute for Crop & Food Research Limited were screened over three seasons (1991–93) to identify material with resistance to cold-induced sweetening. Potato lines were tested 1–2 weeks after harvest using diabetic glucose test tape, and those with glucose levels below 0.1% (1 g/litre) in the potato juices were stored at 4°C for 2 and 4 months. The effect of any changes in sugar levels on chip colour was then reassessed by frying thin slices in oil and measuring the development of Maillard browning in individual crisps by image analysis. Tubers which failed to produce crisps of an acceptable colour were reconditioned at 18–20°C for up to 4 weeks and retested. Lines with potential to resist cold-induced sweetening or with reconditioning potential were retested for an additional two seasons. Over the three seasons, three cultivars and four breeding selections consistently produced the lightest coloured crisps: ‘ADX248–16’, ‘ND860–2’, ‘Red Dakota’, and ‘Atlantic’ from the United States; and ‘Torridon’, ‘V99’, and ‘V489’ from the United Kingdom. Lines that improved to an acceptable reducing sugar level after reconditioning were: ‘Agria’, ‘Fianna’, and ‘Darwina’ from The Netherlands; ‘Lindsey’, ‘V401’, ‘V402’, and ‘V424’ from the United Kingdom; and ‘Gladiator’, ‘1975.12’, ‘354/12’, and ‘472/8’ from Crop & Food Research. © 1998 Taylor & Francis Group, LLC.