The development and testing of a vacuum assisted juice extraction process

The application of vacuum during pressing of apple mashes is reported. Apple mash was pressed in a batch system designed to allow application of vacuum to the outlet side of a press screen. Preliminary results indicated significant improvement in throughput rates (up to 100%) when moderate vacuum was applied. Modest yield improvements were also achieved. When the concept was transferred to a commercially available pilot scale screw press, similar results were achieved. Over a wide range of fruit qualities, storage history and varieties (4) production throughput was improved by more than 50% on average using vacuum in the range of 40–70 kPa. Yield improved by 2% (P < 0.01) and without affecting suspended solids in the juice. Improvements in production efficiency would have considerable economic impact over a processing season.