So, THIS is why 
we’ve been seeing so many juices labeled ‘raw’ nowadays! HPP refers to high pressure ‘pascalization’ (read closely – it’s pascalization, not pasteurization), a process used to extend the shelf life of some foods and beverages by destroying pathogens that accelerate spoilage. For those with suppressed immune systems, this can be a Godsend.
But most people just want to know if HPP leaves the enzymes in their juice altered. The short answer is yes, though the longer answer may surprise you…
– Some enzymes (like PG and LOX) are particularly sensitive to pressure, while others are highly resistant (PPO, POD, and PME) .
– Results also depend on the environment, and composition of the fruits or vegetables being juiced. For example, a study conducted using tomato juice revealed that HPP-processed versions contained up to 12% more lycopene when compared to the untreated juice, while Beta-carotene content decreased at levels of 5-40% . Antioxidants seem to take the greatest ‘hit’ with HPP, with significant decreases in ORAC, FRAP, TPC, and anthocyanin content observed during processing and storage of strawberry puree samples .
Note: Many juices that are labeled ‘raw’ may not be HPP processed, so don’t make assumptions… just be sure to ask in advance!