Mathieu Guillevic

Effect of a linseed diet on lipid composition, lipid peroxidation and consumer evaluation of French fresh and cooked pork meats.

Twenty castrated pigs [(Large-White×Landrace)×(Pietrain)] (52.9±5.1kg initial body weight) were fed a control or a linseed diet containing 4.2% of extruded linseed. Animals were slaughtered at 106.6±3.7kg live weight. There was no effect of diet on pig performance. Feeding the linseed diet increased the contents of n-3 polyunsaturated fatty acids (PUFA) in chops (raw and cooked), chitterlings sausages, country style pâté, garlic sausages, liver pâté, and smoked belly. However, docosahexaenoic acid (DHA) level was not affected by the linseed diet. The linseed diet produced a robust decrease in the n-6/n-3 and linoleic acid (LA)/α-linolenic acid (ALA) ratios (<4). Feeding pigs with a high n-3 PUFA diet led to a decrease in the oxidative stability of chops, in contrast to smoked bellies for which thiobarbituric acid-reactive substances (TBARS) values were not affected by the diet. However, there was no deleterious effect on consumer overall appreciation of the meat.

Fatty acid composition of several muscles and adipose tissues of pigs fed n-3 PUFA rich diets

During two months, sixty Pietrain×(Landrace×Large White) finishing pigs (50.7 to 115.2kg live weight) received diets containing various levels of C18:3n-3 from linseed and C22:6n-3 from Schizochytrium microalgae to increase the content of these fatty acids (FA) in their lean and fat tissues. Samples of tissues have been extracted from the carcass at the slaughterhouse. Tissues of pigs fed linseed had the highest C18:3n-3 and C20:3n-3 contents, while the C20:4, C20:5 and C22:6n-3 contents increased in tissues with microalgae diets. Diaphragm was fatter, but contained less monounsaturated FA, total n-6 and n-3 polyunsaturated FA (PUFA) than longissimus thoracis et lumborum and semimembranosus muscles due to their different roles. The leaf fat was the most saturated and monounsaturated tissue, regardless of the diet. Adipose tissues located in extremities contained more n-3 and n-6 PUFA than adipose tissues located in the middle of the carcass. This study showed the existence of a PUFA gradient depending on tissue location.