Effect of Adding Oregano Essential Oil, Garlic and Tomato Preparations Separately and in Combination on the Stability of Vacuum-Packed Minced Pork During Storage

This paper investigates the effect of adding oregano essential oil (0.02% v/w), freeze-dried garlic (1%), tomato concentrate (15%) and a combination of all three (in the same concentrations) on the shelf life of minced pork meat. Vacuum-packed samples with additives and a control were stored at 6±1°C for 16 days. Sensory, microbiological and biochemical changes were analysed over the whole storage period. The beneficial effect of oregano essential oil was generally to inhibit lipid oxidation, although its effect on bacterial growth was very weak. Adding tomato concentrate, combined with other additives, slowed the rate of microbiological and sensory changes, but had a marked effect on changes in proteins (SDS-PAGE analysis) and the proportion of meat pigments. The addition of freeze-dried garlic did not cause a substantial reduction of detectable bacteria count. Adding a combination of all three additives resulted in a product with a distinctly longer shelf life.