Electronic Theses and Dissertation

Antioksidan merupakan senyawa yang mampu menghambat kerusakan oksidatif akibat radikal bebas. Cangkang biji pala (Myristica fragrans) berpotensi sebagai sumber flavonoid yang memiliki aktivitas antioksidan. Penelitian ini bertujuan untuk menganalisis pengaruh variasi konsentrasi pelarut, waktu ekstraksi, dan rasio sampel terhadap pelarut terhadap kadar flavonoid total (TFC), serta mengukur aktivitas antioksidan menggunakan metode DPPH. Ekstraksi dilakukan dengan metode soxhletasi menggunakan variasi etanol (96%, 70%, dan 80%), waktu ekstraksi (60 menit, 120 menit, dan 180 menit), serta rasio 1:5; 1:10 dan 1:15. Penetapan TFC dilakukan secara microplate reader dengan metode AlCl₃, begitupula dengan pengukuran aktivitas antioksidan yang dinyatakan sebagai nilai IC₅₀ serta Antioxidant Activity Index (AAI). Hasil menunjukkan bahwa kondisi optimum diperoleh pada etanol 80%, waktu 180 menit, dan rasio 1:10 dengan TFC 1,2710 ± 0,0011 gQE/100 g, IC₅₀ 28,86 µg/mL, dan AAI 1,732 (kategori kuat). Variasi 80%, 120 menit, 1:15 menghasilkan IC₅₀ 54,63 µg/mL dan AAI 0,915 (kategori sedang), sedangkan variasi 70%, 120 menit, 1:10 menghasilkan TFC terendah 1,2143 ± 0,0022 gQE/100 g dengan IC₅₀ 35,45 µg/mL dan AAI 1,410 (kategori kuat). Penelitian ini menunjukkan bahwa kondisi ekstraksi memengaruhi kadar flavonoid total dan aktivitas antioksidan, serta menunjukkan hubungan berbanding terbalik antara TFC dan nilai IC₅₀.

Kata kunci: Cangkang biji pala, flavonoid total, DPPH, microplate reader, AAI, antioksidan

Antioxidants are compounds capable of inhibiting oxidative damage caused by free radicals. Nutmeg seed shells (Myristica fragrans) have potential as a source of flavonoids with antioxidant activity. This study aims to analyze the effect of variations in solvent concentration, extraction time, and sample-to-solvent ratio on total flavonoid content (TFC), as well as to measure antioxidant activity using the DPPH method. Extraction was performed using the Soxhlet method with variations in ethanol concentration (96%, 70%, and 80%), extraction time (60 minutes, 120 minutes, and 180 minutes), and sample-to-solvent ratios of 1:5, 1:10, and 1:15. TFC determination was performed using a microplate reader with the AlCl₃ method, as was the measurement of antioxidant activity, expressed as the IC₅₀ value and the Antioxidant Activity Index (AAI). The results showed that optimal conditions were achieved with 80% ethanol, 180 minutes, and a 1:10 ratio, yielding a TFC of 1.2710 ± 0.0011 gQE/100 g, an IC₅₀ of 28.86 µg/mL, and an AAI of 1.732 (strong category). The 80%, 120-minute, 1:15 condition yielded an IC₅₀ of 54.63 µg/mL and an AAI of 0.915 (moderate category), while the 70%, 120-minute, 1:10 variation yielded the lowest TFC of 1.2143 ± 0.0022 gQE/100 g with an IC₅₀ of 35.45 µg/mL and an AAI of 1.410 (strong category). This study concluded that extraction conditions affect total flavonoid content and antioxidant activity, and demonstrated an inverse relationship between TFC and IC₅₀ values. Keywords: Nutmeg seed shells, total flavonoids, DPPH, microplate reader, AAI, antioxidants