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Conjugated linoleic acid enhanced dairy products, new functional foods of the millennium |
D. V. AMINOT-GILCHRIST1, A. W. Hydamaka1, M. A. H. Ismond1, K. M. Wittenberg2, A. T. Ward2, and J. H. Han1. (1) Department of Food Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada, (2) Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada Dairy products, high in conjugated linoleic acid (CLA) show promise as functional foods due to numerous reported health benefits. Conjugated linoleic acid has been shown to have anticarcinogen and antiatheroclerosis properties. It also has functions in modulating the immune system and regulating body fat. The objectives of this study were to determine the effect of dairy lactation diets, processing and storage on CLA levels in dairy products. Processing variables examined included heat treatments, the addition of whey protein concentrate (WPC) and probiotic cultures. Sensory evaluations of products were also performed. Control and CLA enhanced milk was processed into pasteurized milk, butter and fermented milk products according to standard procedures. Lipids in milk were extracted using chloroform-methanol and methylated with sodium methoxide. Fatty acid methyl esters were extracted with iso-octane and analyzed by gas chromatography. Results indicated that manipulating the diet of dairy cows significantly increased CLA levels in milk fatty acids (2.78%) as compared to control milk (0.40%). Processing of pasteurized milk and fermented milk products and their subsequent storage had no effect on CLA levels. Similarly, various heat treatments of milk had no significant effect on the level of CLA. Processing milk into butter significantly decreased the level of CLA by 4.5%. The addition of probiotic cultures in yogurt and kefir production had no significant effect on CLA levels when compared to products manufactured without probiotics. Conjugated linoleic acid decreased by 9% when WPC was added to yogurt at either 6 or 10%. Sensory evaluation indicated consumer acceptibility of CLA enhanced dairy products. Results from feeding trials, processing and sensory studies indicate the feasibility of producing CLA enhanced dairy products. This will position the dairy industry as an important contributor to the funtional food industry.
Session 73, Dairy Foods: Probiotics and bioactive components in milk
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