Earth Apple (Helianthus tuberosus) phenolic compounds were extracted using two methods ethanol extraction (98 percent ethanol for 24 hours at room temperature) and water extraction (distilled water for 24 hours at room temperature). To measure the sum of phenols in the extract, the Folin-Ciocateu method was used. The alcohol extract gave a higher phenol content of 58.29 mg/g (gallic acid), while the alcoholic extract had flavonoids 26.63 mg/g (gallic acid). Water extract was phenols content of 42.62 mg/g (gallic acid) while the alcoholic extract had flavonoids 11.23 mg/g (gallic acid). The alcoholic extract from Earth Apple gave the highest antioxidant effect at 88.32%, while the water extract was 77.43%. The inhibitory effect of the added Earth Apple extract oil to inhibit oxidation, remove concentrations (0.1, 0.15, 0.2 percent) of Palm Oil and Sunflower oil as it exceeded the reduction of peroxide values during the reservoir periods (15, 30, 45, 60 days).