**6. Conclusions**

*Essential Oils - Oils of Nature*

rather than 5% essential oil [38]. Combination of EOs with different types of packaging is another approach for enhancement of shelf life. For instance, the combination of cinnamon essential oil (1 w/w%) and MAP/vacuum packaging extend the shelf life of salmon. However, the MAP+ cinnamon had a better effect on salmon shelf life and the microbial shelf life reach nine or more days. While it was 6 days for vacuum packaged salmon treated with cinnamon. Moreover, cinnamon had no additional antimicrobial effect on LAB, when salmon stored vacuum or MAP [12]. Furthermore, the vacuum packaged common carp (*Cyprinus carpio*) stored 4°C had high quality with the combination of cinnamon essential oil. In addition, cinnamon essential oil inhibited the *Aeromonas* and *Lactococcus* on day 10. *Pseudomonas* and H2S-producing bacteria count was lower in treated fillets and did not exceed the microbial level of 7 log CFU/g at the end of the fillet's shelf life. Moreover, was effective in inhibition the increase of TVB-N and the accumulation of biogenic amines. TVB-N value fluctuated in 6.21 and 9.90 mg/100 g before 12 days treated sample contained and the highest value (15.15 mg/100 g) occurred at day 14. Moreover, crap fillets treated with cinnamon essential oil exhibited the acceptance longer sensorial shelf life (14 days) [39]. The Flounder fillet covered with clove essential oil agar films (0.5 g clove essential oil/g agar) had high low microbial count because of the great antimicrobial activity of clove essential oil against pathogens such as *Staphylococcus aureus*, *Yersinia enterocolitica*, *Aeromonas hydrophila*, *Debaryomyces hansenii* and *Listeria innocua*. The chemical indicators such as TVB-N was 25.83 mg TVB-N/100 g after 15 days of storage. The low total volatile bases and pH values and inhibitory effect on H2S producing microorganisms suggested clove essential oil could be suit-

able biopreservative for the flour fillet shelf life extension [40].

demonstrated magnified antibacterial (691 and 513.33mm2

on Gram-negative bacteria, was observed [42].

In another study, the active films accommodated by poly lactic acid enriched with ZnO nanoparticles (1.5%w/w) and *Zataria multiflora* Boiss (0.5, 1, 1.5%w/w) and the effect of this film on shelf-life extension of refrigerated *Otolithes ruber* fillet during 16 days was investigated. One aspect of shelf-life extension effect is the antibacterial activity of the films which in this case was conducted against *Escherichia coli*, *Salmonella enterica*, *Pseudomonas aeruginosa*, *Bacillus cereus* and *Staphylococcus aureus* by disc diffusion procedure. PLA/ZnO/ZEO and PLA/ZnO/MEO [*Zataria multiflora* Boiss. essential oil (ZEO) and *Menta piperita* L. essential oil] films

*aureus*). The authors expressed that according to the microbial count, the active film remarkably enhanced the shelf-life extension from 8 to 16 days. Chemical factors such as TBARS and TVB-N were also determined. The fillet wrapped with PLA/ ZnO containing 1.5% ZEO, showed the lowest TBARS (0.8 mg MA/kg muscle) and TVB-N (21.23 mg/100 g muscle). GC/MS analysis of EOs showed that the carvacrol and menthone were the major components of ZEO and MEO, respectively [41]. A new edible coating of pectin containing clove essential oil (CEO), was assessed to extension of bream (*Megalobrama ambycephala*) fillets shelf-life during 15 days. Physicochemical (pH, PV, TBA and TVB-N), microbiological (Total viable count, Psychrophilic bacteria, Lactic acid bacteria, *Enterobacteriaceae*, *Pseudomonas* spp., H2S producing bacteria) and organoleptic characteristics were analyzed to determine the influences of the pectin-CEO coating. Physicochemical analysis revealed that lipid oxidation decreased. Some other factors such as weight loss, water holding capacity, color, and texture of the fillets were improved as a result of coating with pectin-CEO (**Figure 3**). During 15 days, lactic acid bacteria were not affected by coating. However, the effects of coating on bacterial growth, especially

The effect of chitosan, thyme essential oil and their combination, on the shelflife of vacuum packaged smoked eel fillets at 4°C, was investigated and according to sensory odor analysis the shelf-life of chitosan/thyme and chitosan-thyme

, respectively, against *S.* 

**198**

During the past decades, EOs have achieved great attention due to their food preservation effects, particularly for the antimicrobial and antioxidant effects.

The EOs of different sources from land and the seas, have variety of phenolic and non-phenolic components which the most actives are low molecular weight terpenoids, terpenes, and aliphatic chemicals (obtained data from analysis by GC-MS and GC/FID in literature). These EOs have shown significant antioxidant, antimicrobial activities which can extent the shelf-life of seafood products. However, it is still mandatory to inquire into cytotoxicity and toxicity of these EOs.
