Pengaruh perbedaan warna pigmen beras organik terhadap aktivitas antioksidan

Organic Rices, such as Jasmine variety white organic rice, Saodah variety red organic rice, and Java variety black organic rice, are many cultivated by farmer in Indonesia, especially Sleman area, DI Yogyakarta. The potency of three varieties of organic rice as antioxidant source hasn’t been studied. Therefore this research was done to know the effect of pigment color difference in three varieties of organic rice on antioxidant activity, especially 1,1-diphenyl-2- pycrylhydrazyl (DPPH) radical scavenging activity and ion reducing power. The results showed that Saodah variety red organic rice had the highest antioxidant potency because it had the highest total phenol and total flavonoid, 37.93 mg GAE/g sample dry base and 0.85 mg CE/g sample dry base, respectively. However Saodah variety red organic rice had total anthocyanin lower than that of Java variety black organic rice, 0.0025 mg/g sample dry base and 0.024 mg/g sample dry base, respectively. Anthocyanin compounds identified in three varieties of organic rice were cyanidine-3-glucoside at 32 minute time retention and peonidine -3-glucoside at 37 minute time retention. 1,1-diphenyl-2-pycrylhydrazyl (DPPH) radical scavenging activity and ion reducing power of Saodah variety red organic rice were the highest, 0.90 mg equivalent vitamin E/g sample dry base and 278.28 mg equivalent vitamin E/g sample dry base, respectively. Keywords: Pigment, organic rice, antioxidant activity ABSTRAK Beras organik, meliputi beras putih varietas Jasmine, merah varietas Saodah, dan hitam varietas Jawa, banyak dibudidayakan oleh masyarakat di Indonesia, terutama daerah Sleman, D.I. Yogyakarta. Potensi ketiga jenis beras tersebut sebagai sumber antioksidan belum banyak dikaji. Oleh karena itu penelitian ini dilakukan untuk mengetahui pengaruh perbedaan pigmen pada ketiga jenis beras organik tersebut terhadap aktivitas antioksidan, khususnya kemampuan menangkap radikal bebas 2,2-difenil-1-pikrilhidrasil (DPPH) dan mereduksi ion besi. Hasil menunjukkan bahwa beras organik merah varietas Saodah paling berpotensi sebagai sumber antioksidan. Hal ini ditunjukkan dengan total fenol dan total flavonoid beras merah tertinggi dibandingkan kedua beras yang lain, masing-masing sebesar 37,93 mg GAE/g sampel db dan 0,85 mg CE/g sampel db. Meskipun beras organik merah mempunyai total antosianin (0,0025 mg/g sampel db) lebih rendah dari beras organik hitam (0,024 mg/g sampel db). Jenis senyawa antosianin yang terdeteksi pada ketiga jenis organik ini adalah sianidin-3-glukosida yang terdeteksi pada waktu retensi 32 menit dan peonidin-3-glukosida dengan waktu retensi 37 menit. Kemampuan menangkap radikal bebas DPPH dan kemampuan mereduksi ion besi beras organik merah tertinggi, masing-masing sebesar 0,90 mg ekuivalen vit E/g sampel db dan278,28 mg ekuivalen vit E/g sampel db. Kata kunci: Pigmen, beras organik, aktivitas antioksidan