## 4 QS Inhibition in the Context of Fish Preservation
### Examples of Use Anti-QS Agents in Fish Preservation  
To delay spoilage and extend the shelf life of fish, alternative preservation methods involving the addition of compounds with known anti-QS activity were proposed [75]. However, new preservative techniques require extensive research to be effectively applied to fish products due to the different sensitivity of microorganisms to QS inhibiting agents introduced directly into the food matrix compared to the sensitivity of cells to the above agents recorded in vitro [37,67]. The most convenient method of using anti-QS agents is to add them directly to marinades or brine. For instance, fresh salmon samples were immersed in marinade composed of 95% olive oil and 5% vinegar and enriched with pepper EO. After 72 h of incubation, the protease and elastase activities of _P. aeruginosa_ were suppressed by 30-50% and 60-70%, respectively [76]. Moreover, [PERSON] et al. [77] and [PERSON] et al. [78] reported that the shelf life of salmon and silver carp could be extended when marinated with anti-QS agents. Both the addition of cinnamon EO and black cumin extract inhibited microbial proliferation. After 15 days of storage, total psychotropic pseudomonads content was low, lipid oxidation was delayed, and sensory quality (texture, color, and odor) was high compared to control samples [78]. In the work of [PERSON] et al. [37], rosmear extract, buffered vinegar, and their combinations were used as dip treatments against _P. fragi_, _P. psychrophilia_, _Shewanella putreaciens_, and _Shewanella xianenesis_ in common carp meat. The results showed that _Pseudomonas_ strains were more resistant to applied antimicrobials, and only a concentration of 3.13 mg/mL rosmearary extract in vinegar resulted in growth inhibition and lowered lipolytic and proteolytic activity. Although the direct application of anti-QS EOs to fish-based products is the most common application method, the technique has some disadvantages. Indeed higher concentrations of EOs are needed to achieve the same effect in food compared to in vitro approaches. In addition, even at low doses, some EOs could have a negative impact on the sensory attributes. Therefore, an alternative solution is to use edible coating/films enriched with anti-QS EOs. The advantages of edible films are stabilizing volatiles entrapped into their structure, increasing the oxygen barrier, and maintaining sensory and texture attributes [79]. The application of the anti-QS myrtle EO to the chitosan-based nanomatrix of salmon-based products enhanced the activity of the agent against _Pseudomonas_ spp. [52]. _Pseudomonas_ population was maintained at approximately under \(10^{4}\) CFU/g relatives to the control, reaching \(10^{8}\) CFU after 5 days of storage. Chitosan coatings in combination with whey protein and tarragon EO were also tested for their preservative effects on _Scomberoides commensonitanus_ fillets under refrigerated conditions. The applied treatment inhibited the growth of psychotrophic bacteria, delayed the increase in TVB-N content and pH value while significantly reducing lipid oxidation [80]. [PERSON] et al. [81] evaluated the preservative effect of two gelatin coatings, the first combined with ginger and the second with garlic EO for turbid fillets stored for 20 days at \(4\)\({}^{\circ}\)C. The results showed the ability of garlic EO coating to prolong the shelf life of fresh fish. After incubation, the total viable counts of bacteria did not exceed \(10^{6}\) CFU/g, the TVB-N concentration was approximately 20 mg/100 g of product, and the hardness decreased by approximately 53% compared to the control samples [81]. To the best of our knowledge, the use of an AHL-degrading enzyme for fish preservation has only been evaluated in the work of [PERSON] et al. [82]. A combination of bacteriocinnisin, AiiAAI96 AHL-lactonase, and vacuum packaging was used to preserve chilled sturgeon fillets.