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The present study has investigated the effect of nano chitosan (NC)-Iranian tragacanth gum (ITG) composite film along with Eryngium campestre essential oil (ECE) on the shelf life of goat meat at refrigerator temperature (4 °C) during the storage period. For this purpose, the first 5 film treatments including NC, NC−ITG, and NC−ITG+ECE at 0.5%, 1%, and 1.5% of were produced and then the physical, mechanical, antioxidant, and antimicrobial characteristics of the films were determined. Next, six different treated groups (mentioned treatments and control (without film)) were examined for chemical (PV, TBA, TVB-N, pH, and color index), and microbial (TVC, PTC, Enterobacteriaceae, and lactic acid bacteria) and sensory evaluations for 16 days at 4 °C. The composite films containing ECE had better physical and mechanical properties compared to other films (P < 0.05) and these films had antioxidant properties (inhibition of DPPH free radicals) and high antimicrobial properties against the tested pathogenic bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus). The results showed that the NC−ITG+ECE significantly delayed the oxidation of fats in meat and was significantly effective in reducing pH and TVB-N compared to the control during the storage period (P < 0.05). The amount of TVC and PTC during the storage period in the meat treated with ECE at 1 and 1.5% remained below the suggested acceptable limit and the microbial spoilage significantly reduced in these samples compared to other samples. Also, the sensory evaluation results of meat packed with 1% and 1.5% ECE had a high overall acceptance during storage. The results showed that packing meat with NC−ITG+ECE has an inhibitory effect on increasing chemical and microbial spoilage. Considering the relatively similar inhibitory effect of 1% and 1.5% as well as economic efficiency, 1% of essential oil can be an optimal dose. [ABSTRACT FROM AUTHOR]

Edible films along with herbal essential oils can be a safe and suitable way to package food including ostrich meat. The present research was conducted to investigate the effects of the polylactic acid–Iranian tragacanth gum (PLA–ITG) composite film along with zygophyllum eichwaldii essential oil (ZEO) on the shelf life of ostrich thigh meat stored at 4 °C. For this purpose, the first 5 film treatments were produced including PLA, PLA–ITG, and PLA–ITG with concentrations of 0.5%, 1%, and 1.5% ZEO, and the properties of the film were determined. The effect of the mentioned films along with the control treatment (without film) on the chemical (PV, TBA, TVB-N, pH, and color index) and microbial (TVC, PTC, Enterobacteriaceae, and lactic acid bacteria) and sensory properties of ostrich samples were evaluated. According to the results, adding ZEO improved the mechanical and physical characteristics of the composite film. PLA–ITG + 1.5% ZEO has the highest antioxidant (DPPH free radical inhibition) and antimicrobial properties (against the tested pathogenic bacteria) compared to others. The results of the second part showed that the samples packed with composite films containing ZEO showed lower (P < 0.05) chemical and microbial changes than the control. The film containing 1.5% ZEO had the best effects compared to other groups (P < 0.05). This treatment had chemical, microbial, and sensory limits until the end of the storage period, while the control sample could only be stored for 6 days. Therefore, from an environmental and economic point of view, it is recommended to use the (PLA- ITG) composite film with ZEO as biodegradable packaging to increase the shelf life of ostrich meat at 4 °C. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the effect of pullulan-nano clay (Pul-NC) incorporated with the watercress essential oil (WE) and nano essential oil (WNE) on the shelf life of pacific white shrimp (Litopenaeus vannamei) during a period of 16 days at refrigerator temperature (4 ± 1 °C). First, WE were extracted using steam distillation and then microencapsulated by lipozyme. Additionally, five treatments were used to investigate the effect of the coatings on the shelf life of shrimp, including 1: control, 2: Pul, 3: Pul-NC, 4: Pul-NC + WE and 5: Pul-NC + WNE, as well as PV, TVB-N, TBA, melanosis, TVC and PTC and Pseudomonas spp, were measured on days 0, 4, 8, 12 and 16. According to the results, nanoliposome particle size and SNE microencapsulation efficiency were 92.31 nm and 81.29%, respectively. Based on the results, the use of nano-coating led to the reduction of oxidative spoilage (PV, TBA) in shrimp samples during the storage period, and the nano-coating containing WNE had more significant effect (P < 0.05) (PV = 3.89 milliequivalents/g, TBA = 1.86 mg mDA/kg), also this treatment slowed down the increasing trend of TVB-N (25 mg/100 g) at the end of the storage period. The highest microbial load was observed in the control on all storage days (P < 0.05) and by adding WNE and WE to the Pul-NC coating, the microbial load decreased significantly (P < 0.05), and the lowest microbial load was related to Pul-NC + WNE and according to the chemical, microbial and sensory standards of this treatment, they were suitable for human consumption at the end of the storage period. Generally, the use of WNE as a natural preservative along with NC in the structure of active edible coatings based on Pul causes the delay of chemical and microbial spoilage and increases the shelf life of pacific white shrimp. [ABSTRACT FROM AUTHOR]

In this study, the effect of composite chitosan‐chia seed coating (CH‐CG) with Bay laurel (Laurus nobilis) essential oil (BE) in two forms including free and nanocapsulated on the shelf life of quail fillets during the 16‐day refrigeration (4 ± 1℃) period was investigated. For this purpose, first, BE was extracted by Clevenger apparatus. Then, nanoliposomes BE were produced, and the properties of BE and nanoliposomes BE were investigated. In order to investigate the shelf life of quail, 6 treatments were produced including 1: control (C), 2: CH‐CG, CH‐CG+BE at 800 ppm, 3: CH‐CG+BE at 1600 ppm, 4: CH‐CG+nano BE at 800 ppm, 5: CH‐CG+nano BE at 1600 ppm, and periodically chemical parameters (peroxide value, free fatty acid, total volatile basic nitrogen, texture firmness, and chewing ability) and microbial (total viable bacteria (TVC) and psychrotrophic bacteria), and the effect of different treatments on control in Escherichia coli and Staphylococcus aureus inoculated populations in quail was also investigated. The BE had high antioxidant and antimicrobial properties. The particle size and microencapsulation efficiency of BE nanoliposome were 98.3 nm and 75.95%, respectively. The results of chemical and microbial analysis showed that in general, the coating with essential oil slowed down the increasing trend of oxidation and microbial indices compared to the control treatment and nanocapsulation of essential oil has increased its antimicrobial and antioxidant properties (p <.05). At the end of storage period, in all tests, treatments of 3, 4, and 5 had the allowed microbial and chemical range and they also inhibited the growth of these bacteria (p <.05). Overall, considering the higher sensory score of treatment 4 and economic efficiency, it seems that this treatment can be used as a natural preservative in the meat industry. [ABSTRACT FROM AUTHOR]

In this work, essential oil was extracted from nettle leaves and encapsulated in chitosan nanoparticles by a two-stage of emulsion-ionic gelation method. An acceptable retention rate (59.5 to 68.2%) of nettle essential oil (NEO) loaded in chitosan nanoparticles was achieved. Also, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) also confırmed successful introducing and loading NEO in chitosan. The nanoparticles displayed an average size of 208.3–369.4 nm. NEO-loaded chitosan nanoparticles had greater antioxidant activity than the free form of NEO. Furthermore, the antibacterial activity of NEO-loaded chitosan nanoparticles was high against S. aureus and E. coli (inhibition zone diameter of 4.11–3.95 cm). Based on these results, the encapsulation of EOs in chitosan nanoparticles are promising candidate to be used in food and pharmaceutical products for novel applications. [ABSTRACT FROM AUTHOR]

In this study, the effects of different concentrations of chitosan (C)/basil seed gum (B) and nettle essential oil (N) on the quality and shelf life of beef burger were examined during storage at refrigerator (4 ± 1 °C). At first, the chemical compounds of N were measured using the gas chromatography. Then, different concentrations of C (1, 1.5 and 2% w/w), B (0.5, 1 and 1.5% w/w) and N (0.5, 1 and 1.5% w/w) were added in the form of combination to the beef burger. 14 produced treatments (control + 13 treatments) were analyzed by microbial parameters (total viable count, psychrotrophic counts) and chemical parameters (peroxide value, the thiobarbituric acid, the total volatile basic nitrogen and free fatty acid) evaluation at 3-day intervals within 12 days. According to the results, the major constituents of essential oil were phytol (27.34%), α-limonene (19.73%), γ-terpinene (17.21%), and p-cymene (16.41%). The use of C + B + N led to decrease in oxidation and microbial spoilage. The minimum microbial and chemical quality loss during the storage period was observed in treatments (T13: C 2%+ N 1.5% + B 1%), (T8: C 1.5% + N 1.5% + B 1.5%) and (T11: C1% + N 1.5% + B 1%) respectively, and these three treatments had acceptable level of chemical and microbiological parameters by the end of the storage period; however, only T11 was approved by the sensory panelist. According to the results, T11 can be applied in the meat-product industry in order to improve the quality of beef burger. [ABSTRACT FROM AUTHOR]

The effects of chitosan coating incorporated with eucalyptus essential oil and α-tocopherol on the quality of silver carp fillet during chilled storage (4 + 1°C) were examined over a period of 16 days. The control samples (without any coating), chitosan coating (CH), chitosan coating incorporated with eucalyptus essential oil (CH+EEO) and chitosan coating incorporated with eucalyptus essential oil and α-tocopherol (CH+EEO+α) were analyzed by chemical, microbiological and sensory characteristics. Results showed that, total viable counts, total psychrotrophic counts and total volatile basic nitrogen of CH+EEO and CH+EEO+α were significantly lower than control and CH ( P ≤ 0.05). Addition of α-tocopherol to EEO retarded lipid oxidation. According to the sensory analysis results, CH+EEO+α was acceptable even at the end of the 16-day storage. The results indicated that chitosan coating was improved extending of meat shelf life. Using eucalyptus essential oil and α-tocopherol increased its efficiency significantly. Practical Apllications Fresh fish are usually more perishable than most other muscle foods. Many attempts have been made to prevent the spoilage of fresh fish. To avoid the use of synthetic food additives, numerous studies are currently focused on using natural products to improve the quality of sea food products. The results of the present study report the efficacy of chitosan edible coating enriched with eucalyptus essential oil and α-tocopherol as a new natural preservative for developing the shelf life of silver carp fillets. [ABSTRACT FROM AUTHOR]

Abstract Carboxymethyl cellulose (CMC)-agar biocomposite film was developed by a solvent casting method and the effects of summer savory essential oil (SSEO) at 0.5, 1.0 and 1.5% v/v on antimicrobial, microstructural, mechanical and optical properties as well as water sensitivity of the films were studied. Results showed that incorporation of SSEO into the biocomposite film developed active films with good growth inhibition activity against Gram-positive bacteria (S. aureus , B. cereus and L. monocytogenes) and less powerfully against Gram-negative bacteria (E. coli). Addition of the SSEO at 1.0 and 1.5% increased microstructural heterogeneity of the films and hence significantly (p < 0.05) increased water vapor permeability of the films while reducing their tensile strength. In contrast, mechanical flexibility and surface hydrophobicity of the films were significantly (p < 0.05) improved as a function of SSEO addition. The active films showed substantially lower swelling ratio compared to the CMC-agar film when 1.5% SSEO was added, but the transparency of the films was reduced. Finally, the results showed that SSEO can act as an antimicrobial agent in combination with CMC-agar film. However, it modifies properties of the film depending on the applied concentration. Graphical abstract Unlabelled Image Highlights • An active film was developed by addition of summer savory EO to CMC-agar biocomposite. • Minimum EO content inducing antimicrobial activity in the biocomposite film was 1%. • The active films showed good antimicrobial activity against gram-positive bacteria. • Mechanical flexibility and hydrophobicity of the films were improved with the EO. • Summer savory EO increased microstructural heterogeneity and WVP of the films. [ABSTRACT FROM AUTHOR]