| Popis: |
The present study aims to characterize the shelf life time effect on residual levels of nitrite, lipid oxidation and color of commercial jerked beef. Twelve samples from four different manufacturers, were collected in three shelf time slots (0 to 60, 61 to 120 and 121 to 180 days) and their nitrite concentration, lipid oxidation (TBARS) and color parameters (colorimeter and preference by ranking test) were assessed. The jerked beef (JB) samples contained up to 23.56 ppm of residual nitrite which meets the legal limits. Mean concentrations of this salt was not influenced by length of shelf life, however, a wide content variation among brands was found. Lipid oxidation means did not differ between products from different manufacturers but showed reductions after 120 days. Luminosity (L*) and redness (a*) were distinct among brands and lowered after 120 days, thus indicating discoloration and darkening. The yellowness (b*) was not influenced by manufacturer or shelf life time. The product with highest visual sensory acceptance had also more intense redness as well as lower rancidity and residual nitrite levels. Shelf life time proved to be a limiting factor to quality of jerked beef due to development of oxidation, darkening and impaired red color. The residual nitrite concentration was mainly influenced by variation between brands while evolution of shelf life promoted higher oxidation levels, loss of luminosity and red color. The most preferred sample had more redness and lower lipid oxidation, hence showing importance of nitrite to maintain quality during storage of JB. Key words: Antioxidant, curing, intermediate moisture, rancidity, salting. |
