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Effects of high conjugated linoleic acid (CLA) on yogurt quality |
M. L. AKINS1, S. E. Duncan, K. M. Waterman, and J. H. Herbein. (1) Department of Food Science and Technology, Virginia Polytechnic Institute and State University, FST Building, Duck Pond Dr., Blacksburg, VA 24060-0418 Studies have shown that an increased consumption of food products containing high conjugated linoleic acid (CLA) content can reduce human tumor growth and decrease body fat mass while increasing lean body mass. Dairy products would be an excellent vehicle for delivery of CLA. Determination of whether modification using specific unsaturated fatty acid profiles (cis9, trans11-18:2 (9/11CLA) and trans10, cis12 – 18:2 (10/12CLA)) would present textural or sensory issues in full fat yogurt were examined. Differences relating to reformulation of butteroils into stable emulsions were also considered. Three different milkfat compositions were obtained through dietary manipulation of cows yielding high oleic and high linoleic milkfats (70:30 w/w) with increased levels of one of two different isomers and standard milkfat. Three different yogurt formulations were composed from the three milkfats (9/11CLA, 10/12CLA, and natural). Two additional yogurts (high oleic and high linoleic (70:30 w/w) and natural milkfat) were formulated to determine if issues existed with emulsification of butteroils into stable emulsions. Samples were analyzed to measure differences in composition (microbiological, protein, fat, and total solids) and quality (firmness, syneresis, and smoothness). Other than fatty acid composition, no significant differences (p<0.05) were found concerning the composition of yogurt formulation or syneresis when compared to natural milkfat yogurt formulation. Textural differences (firmness) were observed between the two isomer formulations and the natural milkfat (9/11CLA 44.5 ± 2.1, 10/12CLA 40.5 ± 2.1, natural 58.4 ± 4.9 (grams of force)). Sensory analysis resulted in no significant differences based on the characteristic of smoothness. These results indicate that although differences in firmness were evident, those identified were not considered significant by sensory panels. This suggests that increasing the conjugated linoleic acid content of milkfat will not alter the quality of yogurt. Yogurt would be an excellent delivery vehicle for CLA as an increased health benefit for dairy consumers.
Session 73, Dairy Foods: Probiotics and bioactive components in milk
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