Irradiation effect on fatty acid composition and conjugated linoleic acid isomers in frozen lamb meat

• Published in: Meat science Vol. 77; no. 4; pp. 689 - 695
• Main Authors: Alfaia, Cristina M.M., Ribeiro, Paulo J.L.C., Trigo, Maria J.P., Alfaia, António J.I., Castro, Matilde L.F., Fontes, Carlos M.G.A., Bessa, Rui J.B., Prates, José A.M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2007; Elsevier
• Subjects: autoxidation; Biological and medical sciences; CLA isomers; conjugated linoleic acid; Fatty acid composition; Food industries; food irradiation; frozen meat; frozen storage; Fundamental and applied biological sciences. Psychology; gamma radiation; Irradiation; Lamb meat; lipid content; lipid oxidation; lipid peroxidation; Meat and meat product industries; nutritive value; omega-3 fatty acids; omega-6 fatty acids; oxidative stability; polyunsaturated fatty acids; saturated fatty acids; trans fatty acids; PUFA; DAD; MUFA; LT; TFA; SFA; Fatty acid composition; FAME; SEM, standard error of mean; Irradiation; CLA; Lamb meat; CLA isomers; Polyunsaturated fatty acid; Meat product; Lipids; Fatty acids; Linoleic acid; Isomer; n-6 fatty acid; Frozen product; Chemical composition
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2007.05.025

The effect of gamma radiation processing on the lipid content, fatty acid composition and conjugated linoleic acid (CLA) profile in frozen lamb meat was investigated. Samples of longissimus thoracis muscle from lambs fed lucerne basal diets either unsupplemented or supplemented with polyunsaturated vegetable oils were irradiated (7 kGy) and analysed. CLA contents in lamb meat did not affect ( P > 0.05) the levels of lipid oxidation induced by the irradiation. No significant differences ( P > 0.05) were observed for fatty acid composition, related nutritional indexes ( n − 6/ n − 3 and PUFA/SFA), as well as for total lipid and CLA contents, between non-irradiated (control) and irradiated meat samples. In contrast, meat irradiation affected the relative proportions of total trans, trans and cis/ trans CLA isomers ( P < 0.001), in addition to the percentage of some minor individual CLA isomers ( t11, t13 and t9, t11, with P < 0.05 and P < 0.001, respectively). The percentage of total cis/ trans CLA isomers slightly decreased in irradiated samples, while the relative proportion of total trans, trans isomers slightly increased. This observation may be explained by the higher susceptibility to autoxidation of the cis double bond relative to the trans configuration.