Effect of ripening on total conjugated linoleic acid and its isomers in buffalo Cheddar cheese

Abstract

Cheese is a biologically and biochemically dynamic product in which a series of sequential changes take place throughout its manufacture and subsequent ripening. These changes improve nutritional value, body and texture and enrich the flavour. Conjugated linoleic acids (CLA), a group of naturally occurring geometrical and positional isomers of linoleic acid, are present in high concentration in dairy products and fat from ruminant animals. Six isomers of CLA have been separated and identified by gas liquid chromatography (GLC) analysis. Buffalo milk had higher 9c,11t‐18:2 isomer (86.14%). Total CLA concentration of CLA isomers was increased significantly (P < 0.05) on conversion of milk into cheese and subsequent storage. The concentration of the 9c,11t‐18:2 isomer was decreased significantly (P < 0.05), whereas that of trans, trans‐isomers (12,14‐; 11,13‐; 10,12‐; 9,11‐) increased significantly (P < 0.05).