Microstructural properties of fat during the accelerated ripening of ultrafiltered-Feta cheese

A commercial pregastric lipase was used to accelerate lipolysis of Iranian ultrafiltered-Feta (UF-Feta) cheese. Scanning electron microscopy images showed that with an increase in lipase levels from 2.0 to 6.0 g 100 kg−1 of retentate, disruption of fat globules increased significantly. On day 3 of ripening and enzyme level of 2.0 g 100 kg−1 of retentate, individual fat globules and fat aggregates were clearly observed on the cheese samples. An increase in the lipase level or ripening period resulted in an increase in the rate of disappearance of fat globules. After 20 days of ripening, no apparent fat globules were observed and fewer fingerprints and voids of free fat were detected, compared to when no enzyme was used.