Studies On The Extraction Technology Of Propolis And Its Antioxidant Activity

Propolis provided by Hangzhou donghai Bee-products Company was selected as raw material in this study to investigate various factors, which influence property of propolis extraction. The flavonoid in propolis was also studied for its scavenging effects on free radical in CuSO4-Vc-H2O2 system and lipid system. The results indicated that:1. The content of effective component (CEC, include total flavones and total hydroxybenzene) were different when propolis was extracted by solvent arrange from low to high according to their polarity. In addition, the CEC rose as the solvent polarity rose. Furthermore, when EtOH was selected as solvent, concentration of EtOH mainly contributed to CEC. It was found that CEC of total flavones is 5.62% and total hydroxybenzene is 6.75% when 95%EtOH was used as solvent; while used 35%EtOH, the correlative value is 2.08% and 2.91% respectively. Processing time also cause different CEC, they have a positive correlation. Processing temperature has some effects on CEC, but not as markedly as concentration did.2. Different extraction methods test showed that: ultrasonic extraction and thermo reflux almost have the same effect on CEC, both excelled cool EtOH zsoakage. Ultrasonic extraction has many advantages, such as: fast (average processing time is 20min), mild action condition (for instance, low temperature can avoid volatilization of some naphtha), easy to control etc. So in future this new technology will have a widely use in propolis extraction.3. Beeswax is considered as trash in propolis extractum. Two processing were compared to understand which has low beeswax content and high CEC. The result indicated that when propolis was extracted with hot water (thermo reflux) first, its residue processed afterward with 95%EtOH, high quality propolis extractum could be gotten. The control propolis was extracted by 95%EtOH(thermo reflux) from beginning to end. Moreover, water-soluble propolis has many special physiological functions. So it seems the first processing was more flexible.4.Two drying methods (vacuum freeze-dry, hot blast dry,) were compared. Result indicated that propolis extractum processed by vacuum freeze-dry method got an advantage over hot blast dry in several facets: CEC activity and liability to form propolis powder, etc.5.The peroxy radical and hydroxy radical scavenging of propolis was investigated. The results showed that propolis could scavenge with dose-dependent effect, propolis might be a kind of high quality foodstuff that could produce antioxidative and functional food.