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All Journal KOVALEN: Jurnal Riset Kimia
Hardi Ys
Universitas Tadulako
Chemical Engineering, Chemistry & Bioengineering Chemistry

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PERSEN DEGRADASI EKSTRAK ETANOL KELOPAK BUNGA ROSELLA (Hibiscus sabdariffa L.) SELAMA PENYIMPANAN THE PERCENTAGE OF ETHANOL EXTRACTS OF ROSELLE PETALS (Hibiscus sabdariffa L.) DURING STORAGE firmasari firmasari; Ni Ketut Sumarni; Ruslan; Hardi Ys
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (501.755 KB) | DOI: 10.22487/kovalen.2019.v5.i2.9970

Abstract

Ethanol extract of roselle petals (Hibiscus sabdariffa L.) is more stable in low pH than in high pH. The research aims to monitor and determine the effect of ratio content in ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce and the pH effect on the percentage of ethanol extract degradation during storage. Two independent variables implemented in this study, are ratio content of ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce and pH. Ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce with ratio content 0,5:1; 1:1; and 1:0 (w/w) and adjusted to pH 2, pH 3, pH 4, pH 5 and pH 6, respectively were investigated. The absorbance measurement of Ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce was depend on each treatment, then analyzed using completely randomized design. The percentage of ethanol extract of roselle petals (Hibiscus sabdariffa L.) degradation in tomato sauce decreased in ratio content 1:0 (w/w) at pH 2 with percentage content of degradation is 30.09%. Furthermore, after 10 days of storage, the highest percentage of ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce degradation is 93.33% with ratio content is 0.5:1 at pH 6 and the lowest is 30.09% with ratio content 1:0 at pH 2. Keywords: Roselle petals, Ethanol Extract, Tomato Sauce, Percentage of Degradation
POTENSI ANTIOKSIDAN METABOLIT SEKUNDER FRAKSI ETIL ASETAT DARI KULIT BATANG EBONI (Diospyros celebica Bakh.) Vivi Sasmita; Ahmad Ridhay; Hardi Ys
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (676.081 KB) | DOI: 10.22487/kovalen.2019.v5.i2.11642

Abstract

Research on the antioxidant potential of the secondary metabolite compound, ethyl acetate from ebony bark (Diospyros celebica Bakh.) has been conducted. This study aims to characterize and determine the antioxidant activity of secondary metabolites of ethyl acetate fraction from ebony bark. Ethyl acetate extract was fractionated using Liquid Vacum Chromatography (KVC) and Gravity Column Chromatography (KKG). The isolated compounds were characterized using UV-Vis and IR spectrophotometers. Data on maximum absorption of λmax 273 nm from UV-Vis analysis showed the presence of chromophore phenol. IR spectral data showed several specific peaks, among others, at wave number (ʋ) of 3425.58 cm-1 indicating the presence of –OH group, C-H aliphatic bond at ʋ of 2924.09 cm-1 and 2854.65 cm-1, and the peak at ʋ of 1604.77 -1465.90 cm-1 and 3078.39 cm-1 indicated the aromatic group, reinforcing the assumption that the isolates produced were phenolic compounds. IC50 value of 75.47 µg/mL from antioxidant activity testing showed that the isolates obtained were antioxidant compounds with strong antioxidant categories. Keywords: antioxidant, Diospyros, ebony, phenolic, isolation
Co-Authors Ahmad Ridhay firmasari firmasari Ni Ketut Sumarni Ruslan Ruslan Vivi Sasmita