Apply GM(0,N) in Determinants Research by Supercritical Carbondioxide Fluid Extracts for Antioxidative Composition of "Hibiscus Sabdariffa" Linnaeu

Low temperature and high diffusion capabilities are characteristics of Supercritical Carbon Dioxide Extraction Technology; it is able to extract the thermally unstable substance from natural products while retaining the active components. Therefore, this study uses Supercritical Carbon Dioxide Fluid Extraction Technology to extract Roselle polyphenols Caffeic Acid. Roselle contains polyphenols which has a lot of bioactivity, in which the active ingredient caffeic acid possesses antioxidant, capture of free radicals and inhibition of tyrosinase functions. Different proportions of water and ethanol as a cosolvent added to the carbon dioxide supercritical fluid for modification; changing flow rates of critical pressures, critical temperatures and supercritical fluids to arrive at the related assessment factors and using the grey GM (0,N) model from the grey theory to analyze the importance of each impact factor. The results show that in antioxidant activity, ability to catch free radicals and inhibition of tyrosinase; the extraction temperature is proven to be the most important impact factor. Compared with using traditional statistical analysis, the grey theory analysis method is able to give more magnitude and association relationships from less information.