Lipids of potato tubers. III. Effect of growth and storage on lipid content of the potato tuber

The effect of physiological changes on the lipid content of six varieties of potato tubers was studied. No significant varietal differences were observed. A marked decrease occurred in the amount of total lipid and fatty acids during the initial weeks of growth, followed by a levelling off during maturation and subsequent storage at 5 ºC. After 6 months' storage, the early maturing varieties revealed a large degree of sprouting with an accumulation in both total lipid and fatty acid content. Palmitic, linoleic and linolenic acids represented 95% of the fatty acids and throughout these studies the relative proportions of the major fatty acids remained constant. Chromatographic analysis demonstrated very little change in the polar lipids, but minor trends among the neutral lipid classes were detected. In the early stages of growth of the tuber the triglyceride level fell rapidly, but later, following the break of dormancy in the stored tuber, there was a regeneration of triglyceride accompanied by a noticeable rise in sterol and carotenoid content.