PROCESS FOR THE PREPARATION OF WILD BLUEBERRY EXTRACT DRY POWDER WITH HIGH CONTENT ANTHOCYANOSIDES

摘要

The invention relates to a process for manufacturing dry powder of Wild blueberry extract which has clear color and contains anthocyanoside used for improving eyesight. The process comprises the steps of: (1) quick freezing fresh wild blueberry fruits at -20 to -40 deg.C; (2) crushing frozen fruits; (3) adding citric acid to the juice to make pH 1.0-3.4; (4) extracting the juice in edible alcohol by a ultrasound extractor (20-30kHz); (5) concentrating the filtrate under nitrogen atmosphere, in vacuum at not more than 10 deg.C; (6) quick freeze drying of the extract, followed by grinding to produce powder having a particle size of 44-350 Pm.