Hydrolyzing Whey Protein?

How is the whey protein concentrate in most supplements hydrolyzed? I’ve read the peptide bonds are enzymatically broken down into shorter chains of aminos, resulting in better absorption in the gut.

What enzyme(s) is/are actually used to do this? I’ve run a quick search but was met with a lot of different pubmed results; Not sure which one is used in this industry.

Does anyone have a clue?