This study aimed to determine the effects of sonication and acid whey maceration on the oxidative stability, antioxidant activity and angiotensin-converting enzyme (ACE) inhibitory activity of peptides obtained from dry-cured pork loins. The changes in the selected parameters were documented over 7, 21 and 42 days of storage. The lowest antioxidant and angiotensin-converting enzyme inhibitory activities of peptides were noted in batches with curing salt (C) and acid whey (SW) compared to batches with sea salt (S). In this sample range, the lowest oxidation–reduction power values were associated with the use of ultrasound. In addition, higher antiradical activity (against ABTS•+) and reducing power values were observed for the sea salt ultrasound (SU) batches (after 21 and 42 days) and for the acid whey ultrasound (SWU) batches (after 7 and 21 days). Contrasting results were obtained for samples with sea salt (S and SU), which were characterized by a higher content of peptides, better antiradical properties and the highest potential to inhibit ACE (after seven days).