Review

Physico-chemical modifications of conjugated linoleic acid for ruminal protection and oxidative stability

Hyun-Seuk Moon¹ , Hong-Gu Lee² , Chung-Soo Chung³ , Yun-Jaie Choi⁴ and Chong-Su Cho⁴

¹Laboratory of Molecular Signaling, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9410, USA

²School of Bio-Resources and PNU-Special Animal Biotechnology Center, Pusan National University, Miryang, 627-706, South Korea

³College of Agriculture, Life & Environment Sciences, Chungbuk National University, Cheongju 361-763, South Korea

⁴School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, South Korea

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Nutrition & Metabolism 2008, 5:16doi:10.1186/1743-7075-5-16

Published:	1 June 2008

Abstract

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid [linoleic acid (LA), 18:2n-6]. Although ruminant milk and meat products represent the largest natural source of CLA and therefore, their concentration in ruminant lipids are of interest to human health, chemical or physical modifications of CLA should be needed as a means to enhance oxidative stability, to improve post-ruminal bioavailability, and to increase the clinical application. In fact, CLA are rapidly decomposed to form furan fatty acids when its are oxidized in air, and the effectiveness of dietary supplements of CLA may be related to the extent that their metabolisms by rumen bacteria are avoided. For these reasons, many scientists have examined the effect of manufacturing and protection on the stability of CLA in ruminants and food products. In this review, physico-chemical modifications of CLA for ruminal protection such as calcium salt (Ca), formaldehyde protection (FP), lipid encapsulation (LE), and amide linkage (AL), and for oxidative stability such as green tea catechin (GTC), cyclodextrin (CD), arginine (Arg), amylase, and PEGylation are proposed.