Determination of Antioxidative Properties of Morinda citrifolia Using Near Supercritical Fluid Extraction
CHIN-HUI CHEN1,2, TSUEY-PIN LIN3, YU-LING CHUNG4, CHING-KUO LEE1, DONG-BOR YEH4 AND SHIH-YING CHEN3,5*
1. Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan, R.O.C.
2. Department of Medical Technology, Yuanpei University of Science and Technology, Hsin-Chu, Taiwan, R.O.C.
3. Department of Health and Nutrition, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan, R.O.C.
4. Department of Biotechnology, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan, R.O.C.
5. Department of Applied Life Science and Health, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan, R.O.C.
(Received: September 17, 2008 ; Accepted: August 3, 2009)
ABSTRACT
Limited knowledge is available regarding the hydrophobic antioxidants present in the Morinda citrifolia L (Noni). Moreover, supercritical fluid carbon dioxide (SF-CO2) extraction technique is well known with many superior extraction properties. The purpose of this study was to investigate the antioxidative properties of crude extracts from the leaves, green and brown stems, and fruit of Noni plant obtained by near SF-CO2 extraction. Extracts from brown stems by near SF-CO2 extraction under high pressure and low temperature conditions afforded the highest total phenolic content (23.14 ± 1.83 mg/g) and the best reducing power (59.82 ± 6.28 ascorbic acid equivalents mg/g). It also possessed the greatest antioxidative capacities, including Trolox equivalent antioxidant capacity assay (564.52 ± 41.58 μmol/g), scavenging of 2,2-diphenyl-1-picrylhydrazyl (effective concentration : EC50 = 6.87 ± 0.14 mg/L), and superoxide radical scavenging activity (505.12 ± 26.68 SOD unit/g), which indicated that the antioxidative activity is not only due to phenolic compounds but also due to non-polar antioxidants. Extracts from the brown stems of M. citrifolia could be a significant source of antioxidants when isolated by near SF-CO2 extraction.
Key words: Morinda citrifolia; Noni, antioxidative activity, supercritical fluid carbon dioxide, phenolic compounds, reactive oxygen species