IRRADIATION AND PACKAGING AFFECT THE NITRATE-NITROGEN CONCENTRATIONS OF POTATOES

Russet Burbank and Kennebec potato cultivars were irradiated wit dosages of 0.1 and 1.0 KGy and stored in polyethylene or paper bags for 1 or 3 mo at 5-degrees-C or 20-degrees-C. Tubers receiving irradiation showed a significant (p < 0.01) increase in nitrate-nitrogen concentration as compared to controls. Those receiving the 1.0 KGy dose had the highest nitrate-nitrogen concentration. Tubers stored in polyethylene bags were significantly (p < 0.01) higher in nitrate-nitrogen concentration than those stored in paper bags. Tubers stored at 20-degrees-C were significantly (p < 0.01) higher in nitrate-nitrogen than those stored at 5-degrees-C. These trends were consistent for both cultivars. The cortex region was significantly (p < 0.01) higher in nitrate-nitrogen concentration than the pith region. Kennebec tubers were significantly (p < 0.01) higher in nitrate-nitrogen than the Russet Burbank tubers for all irradiation doses and storage temperatures.