Research On Extraction Technology Of Ginkgo Biloba Acid And Its Antioxidant Activity And Antibacterial Activity

As the origin of the ginkgo biloba, about70%of the ginkgo biloba in the world camefrom China, but in the process of picking ginkgo biloba fruit, a large number of ginkgo bilobaskins which contains a large number of polluting substances, such as ginkgo biloba acid, werenot effectively utilized, and was discarded as a waste, that resulted in environment pollution,and even leaded to human poisoning, if ginkgo biloba acid was effectively utilized, these canproduce high quality the biological pesticide. Therefore research and utilization of phenolicacids from ginkgo biloba sarcotesta play a decisive role for effective development ginkgobiloba resources. This paper study the extraction technology of ginkgo biloba acid, and itsstability, antioxidant activity and antibacterial activity, that lays a foundation of experimentand theory for the research and utilization of ginkgo biloba acid and. This paper researchconclusions are as follows:（1） the optimum process conditions of extracting ginkgo biloba acid by return methodwere extraction temperature for78.5℃, extracting time for3h, ethanol concentration for82.3%, ratio of liquid and material for22.3. The extraction yield of ginkgo biloba acid byreturn method was1.66%. The optimum process conditions of extracting ginkgo biloba acidby microwave extraction were microwave power for294.2W, extracting time for79.6s,ethanol concentration for81.1%, ratio of liquid and material for14.8, The extraction yield ofginkgo biloba acid by microwave extraction was1.57%. Through analyzing extract results ofginkgo biloba acid by return method and microwave extraction, The extraction yield ofginkgo biloba acid by return method was higher than the extraction yield of ginkgo bilobaacid by microwave extraction, but extraction time by microwave extraction was shorter thanextraction time by return method, and the extraction yield of ginkgo biloba acid bymicrowave extraction was helpful for saving energy, and see a promising future.（2） this paper comprehensively study the influence factors of ginkgo biloba acid stability,light had great influence on the stability of ginkgo biloba acid, preservation rate of ginkgobiloba acid was51.2%after ultraviolet treatment for4d, preservation rate of ginkgo bilobaacid was63.1%after outdoor natural light treatment for4d, preservation rate of ginkgo bilobaacid was74.1%after indoor natural light treatment for4d, and preservation rate of ginkgo biloba acid was83.1%after the camera obscura treatment for4d. ginkgo biloba acid wasstable when the pH was1to3, the absorbance of ginkgo biloba acid reduced with the pHincreasing. Temperature had great influence on the stability of ginkgo biloba acid,preservation rate of ginkgo biloba acid was62.1%.when the temperature raised to100℃,H₂O₂had great influence on the stability of ginkgo biloba acid, preservation rate of ginkgobiloba acid was only33.7%when H₂O₂concentration was0.2mol/L. Na2SO3had not greatinfluence on the stability of ginkgo biloba acid, preservation rate of ginkgo biloba acid was84.6%when Na2SO3concentration was0.04mol/L.（3） ginkgo biloba acid had strong inhibition effect to bacteria, mould and Saccharomycescerevisiae, its antibacterial spectrum was wider. The MIC of ginkgo biloba acid was6.25%toEscherichia coli and Salmonella, was12.5%to Staphylococcus aureus and Aspergillus niger,was25%to Bacillus subtilis, Rhizopus and Saccharomyces cerevisiae.（4） ginkgo biloba acid had strong scavenging ability to DPPH·、·OH and O2·, thescavenging ability strengthen gradually with the concentration of ginkgo biloba acidincreasing, the scavenging ability of ginkgo biloba acid was significantly higher than thescavenging ability of BHT, and ginkgo biloba acid had good ability of anti-lipid peroxidationeffect, the ability of anti-lipid peroxidation effect strengthen gradually with the concentrationof ginkgo biloba acid increasing, the ability of anti-lipid peroxidation effect of ginkgobiloba acid was significantly higher than the ability of anti-lipid peroxidation effect of BHT.