OPTIMIZATION OF PHENOLS EXTRACTION FROM ROSELLE (Hibiscus sabdariffa) BY MICROWAVE ASSISTED EXTRACTION AS ANTIBACTERIAL AND ANTIOXIDANT AGENTS OPTIMASI EKSTRAKSI FENOLIK DARI ROSELA (Hibiscus sabdariffa) BERBANTU GELOMBANG MIKRO SEBAGAI BAHAN ANTIBAKTERI DAN ANTIOKSIDAN

Ike Sitoresmi, M Purbowati, Khaswar Syamsu, Endang Warsiki, Herastuti Sri, Ike Sitoresmi, M Purbowati, Khaswar Syamsu, Endang Warsiki, Herastuti Sri
unpublished
ABSTRAK Kelopak bunga rosela merupakan sumber potensial senyawa phenolik. Untuk mendapatkan senyawa bioaktif tersebut digunakan metode ekstraksi berbantu gelombang mikro yaitu ekstraksi menggunakan alat microwave skala rumah tangga. Response Surface Method digunakan untuk menentukan kondisi optimum variabel ekstraksi, yaitu daya gelombang mikro, konsentrasi etanol dan lama waktu ekstraksi. Kondisi optimum proses ekstraksi yaitu pada daya gelombang mikro 250 Watt, konsentrasi etanol 78,36%
more » ... etanol 78,36% dengan lama waktu 4,91 menit. Hasil verifikasi penelitian total phenol yang diperoleh pada kondisi optimum adalah 23,77 + 0,25 mg/g, lebih rendah dari estimasi optimasi proses, yaitu 24,61 mg/g. Kandungan anthosianin, vitamin C dan rendemen MAE berturut turut 14,80 + 0,08; 10,74 + 0,14 mg/g dan 22,09 + 3,3%. Aktivitas antioksidan ditunjukkan dengan zona hambat yang terbentuk 12,6 + 0,6 mm terhadap E. coli dan 11,6 + 0,3 mm terhadap S. aureus. Aktivitas antioksidan ditunjukkan dengan nilai IC 50 202,47 µL/mL ABSTRACT Roselle calyx is rich with phenolic substances. In this study, microwave-assisted extraction was used to extract the phenolic compounds from Roselle calyx. By using response surface methodology, the effects of microwave output power, ethanol concentration and extraction time on total phenols yield were investigated and the optimal conditions were determined as follows: microwave output power 250 W, ethanol concentration 78.36% and extraction time 4.91 min. The estimated values for total phenols yield was 24.61 mg/g obtained at these conditions. The yield of a verification experiment at the optimum condition was 23.77 + 0.25 mg/g total phenols higher than those of conventional method 19.84 + 0.46 mg/g was obtained. The detailed yield consist of anthocyanin, vitamin C and yield of microwave assisted extraction were 14.80 + 0.08; 10.74 + 0.14 mg/g and 22.09 + 3.3% which were higher and significantly different than conventional extraction , which were 9.28 + 0.04; 9.99 + 0.16 mg/g and 16.18 + 1.9%, respectively. Inhibitory zone was 12.6 + 0.6 mm against E. coli and 11.6 + 0.3 mm against S. aureus. IC 50 value of the extract was 202.47 µL/mL. Compared with conventional method, with inhibitory zone 10. 2 + 0.4 mm against E. coli and 9.8 + 0.6 mm against S. aureus. Antioxidant activity expressed with IC 50 value 293.09 µL/mL.
fatcat:rjxq3l2ijbebndydirvzcczvii