Research On Extraction And Purification Of Anthocyanins From Blueberry Processing Byproducts And Antioxidant Activity

Blueberries are much richer in anthocyanin content than other fruits and vegetables, but the extent of its comprehensive utilization are lower. Peels and Marcs of processing are treated as waste, resulting in a waste of resources and causing environmental pollution, so the extraction of active ingredient from blueberry processing products has broad prospects for development. In this study, pulsed electric field was applied to extract the anthocyanins of blueberry processing byproducts. The anthocyanins was purified with macroporous adsorption resin and the antioxidant activity was analyzed to develop a new way of efficient extraction of anthocyanins and providing a theoretical basis for the comprehensive utilization of blueberry processing products.1. The influences of buffer solution pH value, the sample solution pH, balance time and temperature on anthocyanins content was studied. The results showed that blueberry pigment extract are diluted by the same factor with a buffer solution pH=1.0and pH=4.5, respectively. The absorbance was measured at520nm after20min at40℃and anthocyanin content reached maximum at the time.2. The method of pulsed electric field and ultrasonic assisted extraction were used to extract anthocyanins from blueberry processing byproducts. Study extraction solvent, liquid-liquid ratio, ultrasonic power, extraction time, extraction temperature, number of pulse and electric field strength on the influence of anthocyanins extraction yield to obtain the optimum extraction univariate conditions. The contrast test shows that anthocyanins extraction yield by pulsed electric field are higher, lower temperature, and less time consuming.3. Response surface was applied to get the quadratic regression equation between anthocyanins extraction yield (Y) from blueberry processing byproducts by pulsed electric field and liquid ratio (Xi), pulse number (X2), electric field intensity (X3):Y=-194.86+67.05X1+14.03X3-0.41X1X3-4.89X12-0.77X22-0.29X32According to the variance analysis, we obtained optimum parameters, which were electric field intensity of (18.70KV/cm), pulse number of10(ea) and liquid-liquid ratio of1:631(V/V), the maximum amount of anthocyanins was223.13 mg/L. The influence of various factors in the test range on anthocyanins extractionyield of the size of the order: electric field strength、liquid-liquid ratio、pulse number.4. Anthocyanins from blueberry processing byproducts were concentrated withthree types of macroporous adsorption resins with different chemical and physicalproperties (AB-8, D101, NKA-9). Static absorption/desorption experiments showedthat AB-8resin had a higher adsorption capacity and desorption ratio than the others.The time of adsorption to reach dynamic equilibrium was6h and the experimentaldata of adsorption kinetics fitted better to the pseudo-second-order model.5. The Langmuir and Freundlich equation were used to analysis the adsorptionisotherm of anthocyanin at different temperature. The results indicated that Langmuiradsorption isotherm equation can better describe the effect of temperature on AB-8resin adsorption of anthocyanins and the fitting degree was0.99.6. The extract diluted with three times distilled water of2BV/h flow rate canbetter finish the saturated adsorption. Anthocyanins started to break through with5bed volumes of extract loaded and the complete desorption was achieved using3BVof70%ethanol with2BV/h.7. Blueberry anthocyanin of purification with AB-8macroporous resin waspurple black powder, the anthocyanin content and the color value were nearly6timesand7times higher than crude products, the recovery rate reached91.77%.8. The antioxidant activities of anthocayanin from blueberry processingbyproducts were evaluated by determining the total reducing power, the ability of freeradical scavenging on DPPH and hydroxyl, and the inhibiting lipid peroxidation.Anthocyanins have shown some antioxidant capacity in various systems, whichincreased as the concentration. Anthocyanins had a strong antioxidant activitycompared with the control VC.Innovation:PEF is applied for the first time in blueberry processing byproducts to provide anew method for the extraction anthocyanins of high yield and short time-consuming,and open up a new way for the comprehensive utilization of the blueberry processingbyproducts.