Author(s):
Alfaia, Cristina M. M. 
; Ribeiro, Paulo J. L. ; Castro, Matilde L. F. ; Bessa, Rui J. B. ; Prates, José A. M.
Date: 2007
Persistent ID: http://hdl.handle.net/10400.5/254
Origin: Repositório da UTL
Subject(s): Lamb meat; Gamma irradiation; Fatty acids; CLA isomers
Description
Comunicação Oral. Congresso Nacional. Instituto Politécnico de Beja, Escola Superior Agrária de Beja The perception of quality and "healththiness" of food has become the most important factor for decision. ln meat, this aspect is largely related to its fat content and fatty acid composition. Some meat fatty acids play important roles in metabolism and human health. Recent interest in a minor group of fatty acids that are characteristic of ruminant fat, named conjugated linoleic acid (CLA), is also of great nutritional and bíological consideration. One of the major concerns with the existing technologies for food preservation, including irradiation, is that these processes may enhance lipid oxidation and thereby affect meat qualíty . There are attempts to enforce irradition not only for food safety, but also for technological purposes. Even though irradiation is a prospective technology, its application causes physical-chemical and biochemical changes, that may affect nutritional value and sensory characteristics of irradiated food . The aim of this study was to evaluate the effect of gamma irradiation on fatty acid composition and contents of CLA isomers in frosen lamb meat. The major fatty acids were 18:1c9 as monounsaturated, 16:0 and 18:0 as saturated and 18:2n-6 as polyunsaturated fatty acids. No significant differences were observed in fatty acid composition between non-irradiated and irradiated meat samples. The CLA isomeric distribution showed a clear predominance of the c9,t11,c13.18:2 (10.3 and 10.1%) and t7,c9-18:2 (2.91 and 2.94%). It was found that the irradiation treatment, in contrast to the percentages of partial sums of CLA isomers (trans, trans, cis/trans and cis, cis), which showed significant differences (p<0.001), had no effect on the relative proportions of individual CLA isomers (except for the minor t11,t13.18:2 and t9,t11-18:2). In addition, and regarding the health-promoting CLA isomers (c9t11-18:2 and t10c12-18:2), the irradiation process does not negatively alter the composition and nutritional value of lamb meat
