Shelf life of meat from lambs given essential oil-free rosemary extract containing carnosic acid plus carnosol at 200 or 400 mg kg− 1

• 200 or 400 mg kg− 1 dietary rosemary extract (carnosic acid + carnosol) was tested.
• The use of both extract doses extended the shelf life of packed lamb meat.
• Discoloration, lipid oxidation, odor deterioration and microbial spoilage were delayed.

The use of dietary rosemary extract (DRE) at low doses is proposed as a nutritional strategy to improve meat preservation. Lamb diet was supplemented with 0, 200 or 400 mg DRE (containing carnosic acid and carnosol at 1:1 w:w) per kg feed during the fattening stage. Meat quality was evaluated in lamb fillets packed under protective atmosphere and kept in retail conditions for up to 14 days. The effects of diet and storage time were determined on different physical–chemical (L*a*b* color, pH, TBARS, protein oxidation and volatiles from lipid oxidation), microbial (total viable and psychrophilic bacteria, Enterobacteriaceae, molds and yeasts) and sensory (appearance and odor) characteristics of the meat. The antioxidant and antimicrobial effects of DRE on meat were demonstrated. DRE delayed lean and fat discoloration, lipid oxidation, odor deterioration and microbial spoilage, extending the shelf life time of fillets from around 9 to 13 days. Both DRE doses provided similar shelf life extension.