Evaluation of microbial, physicochemical parameters and flavor of blueberry juice after microchip-pulsed electric field.

The effect of microchip-pulsed electric field (MPEF) and high temperature short time sterilization (HTST) technologies on microbiological, physicochemical properties and flavor of freshly squeezed blueberry juice were compared. Under the MPEF treatment at 350 V, total plate count, total yeast and molds were completely inactivated, meanwhile, VitaminC, anthocyanin, total phenols, titratable acid and color had no significantly changes. During storage of 30 days at 4 °C, VitaminC decreased by 11.52% and 26.78% after MPEF and HTST treatments, all treated juices showed to be microbiologically safe, whereas MPEF can protect nutritionally related properties and color of blueberry juice samples more efficiently. Besides, relatively small changes of juice in odor, taste and volatile compounds concentration was observed by MPEF treatment. Hence, application of MPEF may be an ideal alternative treatment to HTST processing in order to ensure longer shelf life, higher functional and nutritional values of blueberry juice.