Lamb meat burgers shelf life: effect of the addition of different forms of rosemary (Rosmarinus Officinalis L.)

The effect of different rosemary formats (powdered: RP; extract: REX; essential oil: REO; oleoresin: ROL) on vacuum-packed lamb meat raw burgers shelf-life was studied. pH, colour coordinates (L*, a*, b*), microbial count (Total viable count, Enterobacteriaceae, Pseudomonas spp., Lactic acid bacteria), and lipid oxidation were analysed during 14 d. A control group, without spice was used. pH decreased (p < .001) in all samples, reaching the lowest values in ROL. L* remained stable, except in ROL (p < .05), a* showed variations in RP (p < .05), and b* in RP (p < .01) and in ROL (p < .001). Differences (p < .001) were found among treatments on lipid oxidation, with the lowest values in RP. The microbial counts increased with the storage (p < .001) in all microorganism groups in all batches. Shelf life was 10 days for RP and control, 14 days for REX, REO and ROL.