Contents of conjugated linoleic acid isomers in ruminant-derived foods and estimation of their contribution to daily intake in Portugal.

摘要

Contents of CLA isomers in the most consumed Portuguese CLA-rich foods (milk, butter, yoghurt, cheese, beef and lamb meat) were examined using silver ion-HPLC. In addition, the contribution of these ruminant-derived foods to the daily intake of CLA isomers was estimated based on Portuguese consumption habits. The total CLA concn. in milk and dairy products ranged from 4.00 mg/g fat in yoghurt to 7.22 mg/g fat in butter, and, regarding meats, from 4.45 mg/g fat in intensively produced beef to 11.29 mg/g fat in lamb meat. The predominant CLA isomers identified in these products were cis-9, trans-11 (59.89-79.21%) and trans-7, cis-9 (8.04-20.20%). The average estimated total CLA intake for the Portuguese population was 73.70 mg/day. Milk and cheese are probably the 2 products with the highest contribution to the final CLA intake, as a result of their high fat content and consumption values. The results also suggested that cis-9, trans-11 and trans-7, cis-9 are the isomers most represented, with, respectively, 76.10 and 12.56% of the total CLA intake. Implications of these results for diet characteristics and human health are discussed.