It can, that's the reason why UHT milk has a relatively short shelf lifespan and degrades despite being devoid of living microorganisms. The enzymes keep doing their work long after the cell membrane is gone.

You might be thinking of something else. UHT has a very long shelf life compared to other forms of liquid milk.

Compared to other forms forms of liquid milk indeed, but it has a rather short shelf life compared to most sterile food. (Imagine if canned meat or fish had the same shelf life than UHT milk…)