Pengujian Aktivitas Antioksidan dan Kadar Antosianin Bunga Rosela (Hibiscus sabdariffa L.)

Abstract. The use of antioxidants is increasingly important as cases of degenerative diseases increase. Antioxidants function to stop free radical chain reactions, preventing oxidative damage. This study aims to determine the antioxidant activity and anthocyanin levels of roselle flower extract (Hibiscus sabdariffa L.) obtained through the maceration method. Extraction was carried out with a solvent and the addition of tartaric acid to pH 1–2. Anthocyanin levels were determined using the pH difference method using pH 1.0 buffer and pH 4.5 buffer with UV-Vis spectrophotometry. Antioxidant activity testing was carried out using the DPPH (2,2-diphenyl-1-picrylhydrazil) method with vitamin C as a comparison. The test results showed an average IC₅₀ value of 83.594 ppm ± 1.120, which indicates a strong potential for antioxidant activity. The results of the determination of anthocyanin levels obtained were an average of 42.14 mg/L ± 0.141. Abstrak. Penggunaan antioksidan semakin penting seiring meningkatnya kasus penyakit degeneratif. Antioksidan berfungsi menghentikan reaksi berantai radikal bebas, mencegah kerusakan oksidatif. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan dan kadar antosianin dari ekstrak bunga rosela (Hibiscus sabdariffa L.) yang diperoleh melalui metode maserasi. Ekstraksi dilakukan dengan pelarut serta penambahan asam tartrat hingga pH 1–2. Kadar antosianin ditentukan menggunakan metode perbedaan pH menggunakan buffer pH 1,0 dan buffer pH 4,5 dengan spektrofotometri UV-Vis. Pengujian aktivitas antioksidan dilakukan dengan metode DPPH (2,2-diphenyl-1-picrylhidrazil) dengan vitamin C sebagai pembanding. Hasil pengujian menunjukkan nilai IC₅₀ rata – rata 83,594 ppm ± 1,120, yang menunjukkan potensi aktivitas antioksidan yang kuat. Hasil penentuan kadar antosianin yang diperoleh rata-rata 42,14 mg/L ± 0,141.