Studies On Constitutes Of Blueberry Anthocyanidin By Microwave-Assisted Extraction And Purification

Blueberry(ericaceae vaccinium) contains rich anthocyanin, which improve its medical and nutrition value. The purpose of this paper is primarily extract the anthocyanin of blueberry by microwave-assisted extraction technology with low efficiency in energy consumption, high efficiency and low pollution. For a high extraction rate, the AB-8macroporous resin was used for anthocyanin extraction fluid. The results show that microwave extraction method is fit for extraction of anthocyanin. The main conclusion can be drawn as follows:The extraction time, extraction temperature, ethanol concentration and solid to liquid ratio were selected as experimental factors. The single factor experiments were conducted to determine the effect of experimental factors on the anthocyanin extraction from powdered blueberry. Based on results of single factor experiment, the central combination test designed by using Design Expert (ver7.1) software was developed to build the quadratic regression models. The optimal parameters for the highest extraction rate of microwave extraction of anthocyanin73.73%was obtained at extraction time of7min, extraction temperature of47℃, ethanol concentration of55%(v/v), solid to liquid ratio of1:34g/mL. According to the ANOVA results, the influencing order of each factor to anthocyanin extraction rate in studied range is:solid liquid ratio>alcohol concentration>extraction temperature>extraction time. The alcohol was used as extraction solvent, which has characteristics of safety, reliable, high efficient and less injury to human to meet contemporary green extraction requirements.The comparison with the extraction rate variation of Heilongjiang and Canada blueberry were in the same range, as extraction temperature of30～70℃, ethanol concentration of40%～80%(v/v), solid to liquid ratio of1:10～1:50with the change of time (0～10min). The results showed that the highest extraction rate of anthocyanin in Canada wild blueberry is88.56%, in the condition of50℃extraction temperature,60%alcohol concentration,1:30solid to liquid ratio. The highest anthocyanin extraction rate in Heilongjiang wild blueberry is obtained under extraction temperature of58.43℃, alcohol concentration of54.69%, liquid to solid ratio of1:30, extration time of5.3min. The results show that microwave extraction conditions for the highest extration rate were approximately same for the two varieties of blueberry. The process parameters are suitable foranthocyanin exactration of both Heilongjiang and Canada wild blueberry.The AB-8macroporous resin was selected as separation material purify the anthocyanin from the extraction fluid. The factors in adsorption phase is adsorb time, pH value and adsorb temperature. Based on the results from the single factor experiment, both central combination test design method and response surface design method were used to establish three factors and three levels quadratic regression model. The optimal process condition was obtained as follows:3h adsorption,18℃adsorption temperature and87.65%adsorption rate. It was found that adsorption time has the most important effect on the adsorption rate of anthocyanin, followed by the pH value, and at least is the adsorption temperature. The effect factors of desorption phase is desorption temperature, desorption time and ethanol concentration. The optimal desorption condition of84.98%anthocyanin desorption rate are obtained as30min desorption time,46.50%ethanol concentration,22℃desorption temperature. The improtant order of each factor on the desorption rate of anthocyann is as follows:desorption time>pH value>desorption temperature.Kinetics of microwave extraction anthocyanin from powdered blueberry was studied by the comparision between microwave and heat reflux extraction method. The results show that microwave irradiation may promot its diffusion speed within materials mean while cause the degradation of bioactivity composition. Comparied with heat reflux extraction method, microwave-assisted extraction method is beneficial to the anthocyanin extraction under certain condition ranges. The process of microwave assisted extraction anthocyanin from powdered blueburry including the extraction and degration phase obey the exponential decay models. And both extraction temperature play the important roles on extraction rate.