Pasteurized lemon juice or fresh squeezed? For example, when tenderizing meat with pineapple or lime, only fresh squeezed retains the enzymes that break down c

Pasteurized lemon juice or fresh squeezed? For example, when tenderizing meat with pineapple or lime, only fresh squeezed retains the enzymes that break down connective muscle tissue. Cans of pasteurized fruit or juice have no effect. I wonder if this effect requires the same fresh source.