Non-conjugated cis / trans 18:2 in Beef Fat are Mainly Δ-9 Desaturation Products of trans -18:1 Isomers

AbstractHuman liver cells (HepG2) were cultured with individualtrans (t) 18:1 includingt6-,t12-,t13-,t14-,t15- andt16-18:1, and retention times of their Δ-9 desaturation products were determined using 100-m biscyanopropyl-polysiloxane and SLB-IL111 columns. Corresponding peaks were found in beef adipose tissues known to have different delta-9 desaturase activities. Further lines of evidence indicating the presence of Δ-9 desaturation products oft-18:1 isomers in beef fat were developed by analysis of fatty acid methyl esters (FAME) fractionated using Ag+-TLC, and by GC/MS. Some of the Δ-9 desaturation products oft-18:1 have been previously identified in ruminant fat (c9,t12- andc9,t13-18:2). Some of the Δ-9 desaturation products oft-18:1 (c9,t14- andc9,t15-18:2) have been previously tentatively identified as different fatty acids, and for the first time we provide evidence of the presence ofc9,t16-18:2, and wheret6,c9-18:2 may elute during analysis of FAME from beef fat.
Source: Lipids - Category: Lipidology Source Type: research