ORIGINAL RESEARCH The effect of pasteurisation temperature on the CLA content and fatty acid composition of white pickled cheese GOKHAN ZENGIN, 1 YAVUZ SELIM CAKMAK, 1 GOKALP OZMEN GULER, 2 EMINE OGUZ, 1 ABDURRAHMAN AKTUMSEK 1 * andMEHTAP AKIN 1 1 Department of Biology, Science Faculty, Selcuk University, Konya, Turkey, and 2 Department of Biological Education, Ahmet Kelesoglu Education Faculty, Selcuk University, Konya, Turkey *Author for correspondence. E-mail: aktumsek@selcuk.edu.tr Ó 2011 Society of Dairy Technology In this study, the effect of pasteurisation temperature on fatty acid composition of cheese was investi- gated. The fatty acid composition of raw and different heat-treated milk, salt and salt-free cheese were determined using cheese made from raw milk at temperatures varying between 70 and 90°C for 5 min. Generally, C 16:0 palmitic acid was the major fatty acid present in all milk and cheese samples. C 18:1 t11 vaccenic acid was the major trans fatty acid (TFA) in all samples. C 18:2 cis-9, trans-11 (Rumenic acid) was the major CLA isomer in these samples. Pasteurisation temperatures had no effect on TFA, CLA and fatty acid composition of the milk and cheese samples. Keywords Pasteurisation temperature, Fatty acid composition, Trans fatty acids, Conjugated linoleic acid, Cheese. INTRODUCTION CLA is a collective term for different positional and geometric isomers of octadecadienoic acid and natu- rally occuring fatty acid found in ruminant fats. Two of the isomers (c9, t11 and t10, c12) are known to possess biological activity (Pariza et al. 2001). Among the fatty acids, great attention is given to n-3 fatty acids (Kris-Etherton et al. 2002) and CLA, which would have beneficial properties for human health (Belury 2002). Some isomers of CLA, in par- ticular c9, t11 and t10,c12, have been associated with the inhibition of carcinogenesis (Ip et al. 1994), decrease of atherosclerosis (Nicolosi et al. 1997), stimulate the immune system (Cook et al. 1993) and reduction of body weights (Belury and Kempa-Ste- czko 1997). CLA occurs naturally in many foods; however, main dietary sources are dairy products and foods derived from ruminants (Chin et al. 1992). However, the adverse effects of trans fatty acids (TFA) on cardiovascular diseases are well estab- lished (Hu and Willett 2002; Erkkila et al. 2008). High-trans-fatty-acid diet causes adverse changes in plasma lipoprotein profile, with an increase in low- density lipoproteins and decrease in high-density lipoproteins (Precht and Molkentin 2000). Milk lipids include anticarcinogenic compounds such as CLA, sphingomyelin and butyric acid (Ames et al. 1995; Parodi 1999). Cheese is a rich source of essential nutrients, in particular, proteins, amino acids, fat, fatty acids, vitamin and minerals. Cheese is an important dairy product and an integral part of a healthful diet because of its substantial con- tribution to human health (Walther et al. 2008). The basic composition of ripened cheese is not significantly affected by the heat treatments (Ata- soy and Tu ¨rkog ˘lu 2008). Processing, such as heat- ing, can change the CLA isomer distribution in dairy products, while the total CLA content is unchanged by conventional processing (Steinhart 1996). Milk and milk products usually undergo dif- ferent changes during their preparation (boiling and microwaving) or processing, which may include moderate or severe heat treatments that can lead to undesirable changes in lipids or proteins. The chemical changes in lipids are generally accel- erated with the severity of the heat treatment and duration of storage. With the exception of micro- wave heating, heat treatments and refrigerated stor- age of milk and dairy products does not cause significant changes in the trans fatty acid isomer and CLA contents (Herzallah et al. 2005). There is some research about the fatty acid com- position and CLA content of dairy products in vari- ous countries (Akalin et al. 2005; Donmez et al. 2005; Seckin et al. 2005; Guzel-Seydim et al. Vol 64, No 4 November 2011 International Journal of Dairy Technology 509 doi: 10.1111/j.1471-0307.2011.00697.x