Penelitian ini bertujuan untuk mengetahui perubahan aktivitas antioksidan, tekstur dan kecerahan ubi jalar ungu selama pengukusan hingga 50 menit. Ubi jalar ungu dikukus pada suhu 75-85°C selama 50 menit. Pada menit ke-30, 35, 40, 45 dan 50 tiga sampel diambil untuk dihaluskan dengan mortar dan dihomogenkan dengan ribbon mixer. Sampel lalu diuji aktivitas antioksidan secara DPPH, tekstur secara texture profile analysis dan kecerahan secara digital. Data lalu dianalisis secara regresi. Seiring lama waktu pengukusan, aktivitas antioksidan dan hardness menurun dengan laju masing-masing sebesar 0,885 %/menit dan 0,794 g/cm2/menit sedangkan cohesiveness, adhesiveness dan lightness meningkat dengan laju masing-masing sebesar 0,0208 mm/h/menit; 0,0094 N/mm; 0,6774 nhg/menit. Dapat disimpulkan bahwa waktu optimal pengukusan adalah 39 menit dengan nilai aktivitas antioksidan, hardness, cohesiveness, adhesiveness, kecerahan masing-masing sebesar 52,75%; 54,35 g/cm2; 0,37 mm/h; 0,53 N/mm; 13,730 nhg.AbstractThis study aimed to determine changes in antioxidant activity, texture and brightness of purple sweet potato during steaming up to 50 minutes. Purple sweet potato steamed at temperature of 75-85°C for 50 minutes. Three samples taken to mash with a mortar and homogenize with a ribbon mixer in minute 30, 35, 40, 45 and 50. Samples were tested the antioxidant activity in DPPH, texture profile analysis and digital colormeter. Data was analyzed by regression. Antioxidant activity and hardness decreased at a rate of respectively 0.885 %/minute and 0.794 g/cm2/minute while cohesiveness, adhesiveness and lightness increased at a rate amounting to 0.0208 mm/h/minute; 0.0094 N/mm; 0.6774 nhg/min a long with steaming time. It can be concluded that the optimal steaming time is 39 minutes with a value of antioxidant activity, hardness, cohesiveness, adhesiveness, brightness respectively by 52.75%; 54.35 g/cm2; 0.37 mm/h; 0.53 N/mm; 13.000 nhg.