Variation in asparagine and glucose contents, identified as precursors for acrylamide development in model experiments, has been studied in eight potato clones during long-term storage at 3 and 10 • C. In addition, glutamine, fructose and sucrose contents were determined and the role of all five substances in colour formation in fried potato products was assessed. Large genotype differences were found in all characteristics, and the ranking order was almost the same for different years and storage times. Breeding for potatoes with low asparagine levels as well as low reducing sugar levels might be another way, in addition to altering processing parameters, to keep the acrylamide level low in fried products. Storage per se at low temperature did not result in higher asparagine levels. The risk that elevated reducing sugar levels during low-temperature storage might lead to increased acrylamide levels needs further investigation. The determined tuber components accounted for only 11-60 per cent of the total variation in fry colour after storage at 3 • C. It is suggested that screening based on crisp colour in November, perhaps complemented with a few later controls on interesting clones, could be useful for sorting out clones with good crisping abilities during the rest of the low-temperature storage season.

No abstract