Study On The Flavonoids Extraction Of Rape Bee Pollen Based On High-Speed Shear Technology

Rape bee pollen is something that bee collect pollen from Brassica napus L. and mix with a small amount of nectar and secretions.It’s one of the sources of China’s major bee polle n and distributed all over the country. Because of strengthening the immune system, anti-agi ng,antioxidant, the inhibition of prostatic hyperplasia and other biological activity, rape bee pol len has been widely used in medicine, food, cosmetics and other fields,especially the flavono ids became a hot topic. High-speed shear technology, as a new micron technology, has been developing rapidly.But it is rarely applied in the field of natural products research and develop ment. In this thesis, the following aspects of the work was carry out:The High-speed Shear Dispersing Emulsifier(HSDE) was used for breaking the walls of rape bee pollen. The effects of time, temperature, revolving speed and ratio of raw material to liquid on the broken rate of the rape bee pollen walls were investigated, and a predictive polynomial quadratic model was set up by means of Box-Behnken central composite design.The optimal conditions of broken process are concluded as follows:time3min, revolving speed22000r·min-1and ratio of raw material to liquid3mL·g-1. Under these conditions, the walls of rape bee pollen are entirely broken.The total flavonoids are extracted from rape bee pollen by High-speed Shearing technique. On the basis of single-factor test, the extraction process parameters are optimized by the Orthogonal design, as the extraction rate, the yield of total flavonoids and DPPH scavenging activity (AE values) for the evaluation.The optimum extraction conditions are as follows: temperature55℃, revolving speed19000r·min-1, ratio of raw material to liquid8mL·g-1and extracted15min for1time.Under this condition, the extraction rate is36.95%, the yield of total flavonoids is21.37mg·g-1and the AE values is2.10×10-2.The kinetic model of the extraction process of flavonoids was presented based on Fick’s second law of diffusion. Finally The kinetic model is proved to be in good agreement with the experimental data.And the extraction process of flavonoids is a First-order kinetics. Correlation analysis showed that there was significant correlation between Flavonoid content and broken rate of the rape bee pollen walls, which inferred that the broken of the pollen cell wall is an important factor affecting the bee pollen flavonoids dissolution.