Fatty Acid Content of Bovine Milkfat From Raw Milk to Yoghurt

Problem statement: The present study aimed to study the evolution of fatty acid content, focusing on rumenic acid content, from raw milk to yoghurt processed from this milk. Approach: Milk samples were collected in a dairy plant in the northwest of Paraná State weekly in January 2011 (Brazilian summer). It processed one truck load of 26,000 L of refrigerated type-C (whole standardized milk with a minimum of 3% fat) milk per day, mostly from the city of Lobato, Paraná, produced mainly by Gir (Bos indicus) cattle raised on stargrass (Cynodon nlenfuensis var. nlenfuensis) pasture. Results: Saturated Fatty Acid (SFA) were the most abundant, particularly palmitic (16:0), stearic (18:0) and myristic (14:0). Among the Monounsaturated Fatty Acid (MUFA), Polyunsaturated Fatty Acid (PUFA) and trans fatty acid, oleic acid (18:1n-9), linoleic acid (18:2n-6), elaidic acid (t9-18:1) and c9, t11-18:2 (rumenic acid) predominated. It was detected significant differences (p<0.05) in the quantification of isomer c9, t11-18:2 of Conjugated Linoleic Acid (CLA). Raw milk had the largest content of rumenic acid (14.91±0.17 mg g^-1 of lipids), decreasing to 6.22±0.20 after pasteurization and to 5.41±0.18 mg g^-1 in yoghurt. Conclusion/Recommendations: It is demonstrated that pasteurization and yoghurt making affect the CLA contents.