Detection of lipid-derived aldehydes and aldehyde : protein adducts in vitro and in beef

Aldehyde lipid oxidation products and protein: aldehyde adducts were detect ed in vitro and in stored ground beef. Propional, pentenal, hexanal and 4-h ydroxynonenal (4-HNE) were the primary aldehydes formed during lipid oxidat ion. The 4-HNE concentration was higher in 1,2-dilinoleoyl-phosphatidylchol ine liposomes (PCL) exposed to Mb than to AAPH (P < 0.05). Elevated concent rations of <alpha>-tocopherol (alpha -Toc) in PCL or microsomes reduced the production of aldehyde lipid oxidation products compared to controls (P < 0.05). Proteins adducted by 4-HNE, malondialdehyde, and hexenal, heptenal, octenal and nonenal (C6-C9enal) were detected in PCL, microsomes and beef b y indirect ELISA. These results demonstrate that aldehydes. produced during lipid oxidation can form adducts with proteins and that this may have impl ications for protein stability and functionality.