Influence of feeding systems on Chemical Contents and Sensory Quality of Longissimus thoracis Lamb Muscle cooked in boil and grill

Abstract

Nutritive and sensory characteristics of the lamb meat depend not only on breeding conditions and systems but also on cooking procedures. The aim of this study was to evaluate the effect of two cooking methods on the nutri-tional and sensory quality of L. thoracis meat from lambs reared in two Alge-rian systems. The lambs grazed either in a highland pasture with a hay sup-plementation, or in a steppe pasture with concentrate supplemention. After three months of grazing, all the lambs from both rearing systems were slaughtered, and eviscerated in a local commercial slaughterhouse. The dis-sected muscles were trimmed, minced in a meat grinder and analysed. Grill-ing and broth cooking were respectively performed at 250°C and 100°C for 30 min. The obtained results indicated that cooking methods had a signifi-cant effect (p <0.05) on all the analyzed parameters. It appeared that fat, water loss and thiobarbituric acid reactive substances (TBARS) values of the samples increased with cooking procedure. Overall, cooking increased total saturated and polyunsaturated fatty acid contents of the intramuscular lipid (p<0.05) while reducing the n-6/n-3 ratio (p<0.001). The results reported on the color analysis indicated significant difference for the red index (p<0.05) which was more predominant in the Steppe fed lamb muscle than in the highland one (14.05 vs. 8.01, respectively). Changes in a* values appeared to be affected by lipid oxidation and are strongly correlated with thiobarbituric acid reactive substances (TBARS) values. Finally, although cooking results in an increase in the lipid oxidation of meat, its nutritional and dietary value is not impaired. It seems that the Algerian rearing systems is an interesting for outdoor sheep breeding and allow to obtain a meat preserving a healthy nutritional quality after cooking.