Effects of field treatments on processing quality of Record and Pentland Dell potatoes during storage

Abstract

SUMMARYPrevious research has suggested that fry colour of processed potatoes is inversely correlated with tuber reducing sugar content, and agronomic practice should therefore be tailored to minimize amounts of tuber sugars at harvest and during storage as a means of maximizing processing quality. A total of 30 experiments from three sites in England from 1985 to 1988 examined this hypothesis for two cultivars using a wider range of husbandry than that used in practice and long periods of storage. No tuber sugar value was sufficiently well correlated with fry colour for the relationship to be interpreted as causal and of use predictively, irrespective of whether it was measured early in growth, at harvest or at the time of processing. Fry colour at harvest was not correlated with fry colour after storage. No agronomic practice (variables used were physiological age, date of planting, irrigation or date of harvest) consistently caused fry colours to be darker than the acceptable colour limit, whether at harvest or after long term storage. Crops producing unacceptable fry colours early in storage generally improved to produce acceptable fry colours after long term storage. Agronomic practices within the range normally found in commercial production are therefore considered to have little effect on long-term processing quality, although harvesting, handling and transport operations were not investigated.