Moringa oleifera Lam. merupakan salah satu tanaman herbal di Indonesia yang mengandung senyawa antioksidan alami. Penelitian dilakukan untuk mengetahui perubahan aktivitas antioksidan pada konsentrasi substrat 5% hasil fermentasi oleh Lactobacillus plantarum InaCC B997 selama 24 jam. Ekstraksi senyawa antioksidan pada serbuk daun M. oleifera dilakukan dengan metode infusa, pada suhu 85̊C selama 30 menit. Aktivitas antioksidan diukur dengan metode DPPH (Diphenyl Plerylhydrazyl) dan mengukur konsentrasi senyawa antioksidan yang mampu menghambat 50% sifat radikal bebas dalam DPPH (Nilai IC50). Hasil penelitian menunjukkan nilai IC50 infusa daun M. oleifera kontrol (nonfermentasi) ialah 137,15 μg/mL, sedangkan pada sampel infusa hasil fermentasi batch I, II, dan III berturut-turut ialah 155,10 ± 14,59 μg/mL, 165,20 ± 2,81 μg/mL, dan 189,77 ± 3,05 μg/mL. Penelitian menunjukkan bahwa fermentasi infusa daun M. oleifera Lam. pada konsentrasi 5% oleh L. plantarum InaCC B997 menurunkan aktivitas antioksidan sebesar 13,08%, 20,45%, dan 38,36% pada batch I, II, dan III.
Moringa oleifera Lam. is one of the herbal plants in Indonesia that contains natural antioxidant compounds. The aim of this research is to determine the antioxidant activity of fermented M. oleifera Lam. leaf infusion at 5% concentration using Lactobacillus plantarum InaCC B997 for 24 hours. The extraction of antioxidant compounds in M. oleifera Lam. leaf powder was carried out by infusion method at 85̊C for 30 minutes. Antioxidant activity was measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method and was evaluated based on the concentration of antioxidant compounds that were able to inhibit 50% of DPPH (Inhibitory Concentration 50). The result showed that unfermented leaf infusion had IC50 value of 137.15 μg/mL, while the fermented leaf infusion had IC50 value of 155.10 ± 14.59 μg/mL, 165.20 ± 2.81 μg/mL, and 189.77 ± 3.05 μg/mL in batch I, II, and III, respectively. This study showed that fermentation of M. oleifera Lam. leaf infusion at concentration of 5% using L. plantarum InaCC B997 had reduced antioxidant activity when compared to nonfermented leaf infusion at 13.08%, 20.45%, and 38.36% in batch I, II, and III, respectively.