Effects of sous vide vs grilling methods on lamb meat colour and lipid stability during cooking and heated display

The present study compared the effect of grilling (150°C until 72°C core temperature) and sous-vide (SV) cooking (75°C for 35 min in a water bath under vacuum) on lamb patties immediately after cooking and after 4 h display at 65°C. Both methods produced patties with similar (P>0.05) weight loss, and moisture and fat contents. SV-cooking prevented (P<0.05) the formation of thiobarbituric acid reactive substances (TBARS) and oxysterols compared to grilled patties, which showed a larger proportion of highly peroxidisable polyunsaturated fatty acids. Heated display induced dehydration, surface darkening and a reduction in the hexanal/3-methylbutanal ratio, suggesting the progression of Maillard reactions. Moreover, TBARS and some lipid oxidation-derived volatiles increased (P<0.001), while cooked-meat aroma compounds were reduced (P<0.001). SV-cooking inhibited (P<0.05) the formation of malondialdehyde, and 7α- and 7β-hydroxycholesterol, and lowered the cholesterol oxidation ratio during heated display. Overall, SV-cooking may be considered a healthier way of cooking when lamb meat is to be kept warm for considerable periods before consumption.