The effect of storage on the yogurt fatty acid profile

Abstract

The presented study analysed whether refrigerated storage time affects the fatty acid profile, the content of conjugated linoleic acid (CLA) and trans isomers of C18:1 and C18:2 acids in yogurts made from goat, sheep and cow milk. On the 21st day of storage, significant decreases (P<0.05) in monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) were observed in in yogurts made from cow milk. In yogurts made from sheep and goat milk, the content of these acids fluctuated during storage. The CLA isomer in fresh yogurts ranged from 3.58 mg g-1 fat in yogurts made from sheep milk to 4.47 mg g-1 fat in yogurts made of cow milk. During storage the content of CLA significantly decreased in cow milk yogurts and significantly increased in goat milk yogurts (P<0.05), while it remained more or less unchanged throughout the entire storage period in sheep milk yogurts.U ovom istraživanju je ispitivan utjecaj hladnog skladištenja na profil masnih kiselina, sadržaj konjugirane linolne kiseline (CLA) te trans izomera masnih kiselina C18:1 i C18:2 u jogurtima od kravljeg, kozjeg i ovčjeg mlijeka. Na 21. dan skladištenja utvrđen je značajan pad (P<0,05) sadržaja jednostruko (MUFA) i višestruko nezasićenih (PUFA) masnih kiselina u jogurtima od kravljeg mlijeka. Sadržaj ovih masnih kiselina mijenjao se u jogurtima od ovčjeg i kozjeg mlijeka. Sadržaj izomera CLA u svježe pripremljenim jogurtima kretao se između 3,58 mg g-1 masti (ovčji jogurt) i 4,47 mg g-1 masti (kravlji jogurt). Tijekom perioda skladištenja se sadržaj CLA značajno snizio u kravljem jogurtu, dok je značajno narastao u kozjem jogurtu (P<0.05), a u ovčjem jogurtu je ostao više manje nepromijenjen.