Samples and atmospheres Semimembranosus muscles, consisting of approximately 85%lean, were excised from 3 beef carcasses 48 h postmortem, and minced using a conventional mincer through a plate with 4 mm holes.
All 3 minced muscles were thoroughly mixed together in a single batch. Portions of uniform weight of the minced muscle (about 85 g) were mixed with salt (2%)and (1) 1% borage, (2) 2% borage, (3) 0.02% oregano, (4) 0.1% oregano, (5) 0.05% ascorbic acid, (6) 0.1% rosemary, (7)rosemary + ascorbic acid (0.1% and 0.05% respectively), and (8)control (no antioxidant treatment).
A total of 200 beef patties were formed, 25 for each treatment, and placed on styrofoam trays.
Eachtray with the round beef patty was introduced in a pouch made ofa polyethylene and polyamide laminate of water vapor permeabil-ity 5 to 7 g/m2/24 h at 23 °C and oxygen permeability 40 to 50 mL/m2/24 h at 23 °C .
The pouches were filled with a gas mixture of 70% O2 + 20% CO2 + 10%N2, and sealed. The gas mixture was supplied by Abelló Linde S.A.,.
The patties were stored for 24 d at 2 + 1 °C in the dark.
Five packs were opened for subsequent analysis for each formulation every 4 d of storage; 2 of them were used for microbial sampling alone, while the remaining 3 were used firstly for sensory analysis, secondly for color instrumental analysis, and thereafter for the determination of pH and TBARS.