A new type feed additive: magnolia bark extract
magnolia bark extract is rich in two biphenol compounds, (magnolol and honokiol), which are thought to contribute to the primary anti-stress and cortisol-lowering effects of the plant., The influence of extraction pressure,temperature and time of supercritical fluid extraction(SFE) on the extract yield of Magnolia officinalis was mainly discussed.The optimum conditions for SFE were as follows: 25 MPa extraction pressure,40℃ extraction temperature,3 h extraction time.Based on the optimum conditions,10% ethanol as modifier was added in,the result showed that it could increase the extract yield and decrease the extraction time.Soxhlet extraction with different solvents was compared with supercritical fluid extraction.The antioxidant activities of these extracts were tested using Oxidative Stability Instrument and their free radical scavenging activity was evaluated by scavenging DPPH,BHT was used as control sample.The investigation indicated that the result evaluated by scavenging DPPH was in accordance with the result tested by OSI,the antioxidant activity of the extracts decreased in the following order: BHT the extract of ethyl acetate the extract of chloroform the extract of SFE-CO_2 with ethanol as modifier the extract of petroleum ether the extract of SFE-CO_2.