Technological options to control quality of fish burgers

This research was focused on preservation strategies applied to develop fish burgers enriched with tomato flour and extra-virgin olive oil. The effects of three different gas mixtures (5:95 O₂/CO₂; 10:60:30 O₂/CO₂/N₂ and 5:50:45 O₂/CO₂/N₂) on burger quality were analyzed by monitoring microbial cell load of main spoilage microorganisms, pH and sensory properties. As expected, modified atmosphere packaging significantly affected mesophilic bacteria with a reduction of about 2 log cycles for samples under 5% O₂ and 95% CO₂. Afterward, the best gas mixture was used in combination with various natural antimicrobial compounds (thymol, grape fruit seed extract and biocitrus). The biocitrus showed the strike balance between microbial and sensory quality, thus suggesting to be adopted for dipping treatment of the entire fish fillet before the mincing process. Later all the strategies tested individually were combined and samples were monitored for microbiological and sensory quality. Results obtained showed that dipping treatment of fillet in biocitrus solution (20,000 ppm) under modified conditions extended the shelf life by 8 days compared to the control sample, without affecting the sensory acceptability.