S. Jeddi, S.a. Jafarpour, S. Yeganeh, M. Naseri,
Volume 7, Issue 1 (3-2018)
Abstract
Aims: With regard to increasing the consumption of seafood in fresh form, the present study was conducted with the aim of investigating color and tissue of Rainbow Trout fillet by chitosan edible coating incorporated with marjoram essential oil during refrigerated storage.
Materials & Methods: This experimental study was conducted as factorial experiment with completely randomized design. Three fillets without coating were treated with 2% chitosan solution and 2% chitosan solution+0.5% of the essential oil and were examined three times for each treatment. The color and tissue properties were evaluated after 0, 7, 14, and 21 days. The data were analyzed by SPSS 22 software, using two-way ANOVA, and Duncan's Multiple Range Test.
Findings: There was no significant difference in the composition of moisture, ash, protein, and total fat between 0 and 21 days at refrigeration temperature. The amount of cold bacteria increased during the storage time and was significantly different in different treatments (p<0.05). The initial number of bacteria showed no significant difference on day 0 between control fillet and treated fillet (p>0.05), but with time, this difference became significant (p>0.05). Fillets treated with chitosan and essential oil resulted in better elastic state and, consequently, better fillet quality compared to the control. The use of 2% chitosan preserved these indices in the fillet without any significant change compared to the control (p<0.05).
Conclusion: Coating Rainbow Trout fillet with marjoram essential oil increases its antimicrobial and antioxidant properties and significantly improves the quality of the color and tissue of the fillets of this fish during refrigerated storage.
Volume 19, Issue 130 (12-2022)
Abstract
The aim of this research was to fabricate wheat gluten based active film containing free and encapsulated Marjoram essential oil (MEO). The MEO was encapsulated by lipid nanocarrier (nanoemulsion) and protein-based nanocarrier (Pickering emulsion by WPI) and used at the concentrations of 1, 3 and 5% in the formulation of gluten films. The free MEO was used at same concentrations. The physical properties of active films and also their performance in the control of microbial spoilage in the real food models including UF cheese and red meat during 9 days of storage were evaluated. The results indicated that the water vapor permeability (WVP) increasesd by increasing free MEO but the encapsulated MEO caused to significant decrease in the WVP values (p<0/05). The tensile strength, Young’s modulus and elongation to break of films decreased by adding free MEO but the encapsulated samples caused to improve the mechanical properties. Moreover, the results of the colony counting of E.coli and L. monocytogenes cultured on the surface of UF cheese and red meat wrapped with active films, indicated that for all samples, the microbial growth had increasing manner during storage and by increasing the concentration of MEO, the microbial count decreased significantly in comparison to the control sample (p<0.05). The encapsulation had no adverse effect on the antimicrobial activity of MEO. Generally, the results of this research indicated that loading of encapsulated MEO causes to improve the physical properties of active gluten film and is able to control the microbial growth in Ultra-refined cheese and meat.
