As a wide range of n-3 fatty acids in oil and powder form are currently available for food fortification, the fatty acid (FA) composition of mashed potatoes (MP) formulated with extra virgin olive oil (EVOO) was analyzed by gas chromatography and compared with the FA profile of MP subjected to a freeze/thaw cycle. MP samples were enriched with n-3 polyunsaturated fatty acids (PUFA) using different concentrations of α-linolenic acid (ALA) (22.5, 30, and 45 g/kg) and n-3 docosahexaeonic acid (DHA)/eicosapentaenoic acid (EPA) (5, 6.25, 7.25, and 10 g/kg) to improve product nutritional quality. ALA was much more chemically stable than DHA and EPA. MP with added ALA at 30 and 45 g/kg and with added DHA/EPA at 5, 6.25 and 7.25 g/kg is considered a source of flaxseed and fish oils n-3 FA, respectively, whereas samples enriched with DHA/EPA at 10 g/kg may claim high fish oil n-3 FA content according to European Regulation. The addition of n-3 obtained from microencapsulated flaxseed and fish oils improved the nutritional indicators that define the quality of the fat, producing a healthier product.