Freshly Squeezed: The Truth About Orange Juice in Boxes
civileats.com/2009/05/06/freshly-squeezed-the-truth-about-orange-juice-in-boxes
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
When the juice is stripped of oxygen it is also stripped of flavor providing chemicals. Juice companies therefore hire flavor and fragrance companies, the same ones that formulate perfumes for Dior and Calvin Klein, to engineer flavor packs to add back to the juice to make it taste fresh.