ABSTRACTChippewa and Katahdin potatoes were examined for susceptibility to enzymatic darkening in relation to lipid content. Comparisons were made between the bud and stem regions of Katahdin tubers for 3 consecutive years and between Chippewa and Katahdin tubers for 1 yr. Enzymatic darkening was always greater and lipid content lower in the stem than the bud region. This relationship was exhibited by both the pith and cortex tissues. The phospholipid fraction followed the same trend as crude lipid, being higher in the bud than the stem end. Chippewa potatoes had a greater crude lipid and phospholipid content than Katahdin potatoes and were less susceptible to enzymatic darkening. The lipid content of the tuber, although present in relatively small amount, is important in determining cellular integrity and resistance to bruising.