Abstract The effect of level (450 or 900 mg laminarin (L) and fucoidan (F) /kg feed) and duration (3 or 6 wks) of feeding a seaweed (Laminaria digitata) extract containing L/F on the quality of pork (longissimus thoracis et lumborum (LTL)) stored in modified atmosphere packs and on organ lipid stability was examined. Mechanisms of L/F antioxidant activity in LTL\ were evaluated. Plasma total antioxidant status, LTL\ pH, colour, microbiology and ‘eating quality’ sensory analysis were unaffected by dietary L/F. ‘Visual’ sensory descriptors (purchasing appeal and overall visual acceptability) were enhanced (p < 0.05) in L/F450 - 3 LTL. Lipid oxidation was lower (p < 0.05) in L/F450 - 3 and L/F900 - 3 LTL\ and reduced in L/F900 - 6 kidney homogenates. In cooked minced pork, lipid oxidation was not reduced by dietary L/F. Saturated fatty acids were lower (p < 0.05) in L/F900 - 6 LTL. Results indicated L/F in pig diets for 3 weeks enhanced pork quality.