Effect of chitosan coating containing Nepeta pogonosperma extract on shelf life of chicken fillets during chilled storage

Extending shelf life of chilled pork pretreated with high-voltage electrostatic field in modified atmosphere packaging by cinnamaldehyde nanoemulsion at non-contact mode

Previous studies have demonstrated the usefulness of cinnamaldehyde nanoemulsions (CNE) combined with high voltage electrostatic field (HVEF) for pork preservation. However, the immersion method severely affects the flavor of the pork while the original color of the pork cannot be controlled. In this experiment, a non-contact mode of oxygen-enriched modified atmosphere packaging (MAP) was proposed for pork preservation. The results showed that CNE would gradually destabilize and then spontaneously release cinnamaldehyde in the package. The pretreatment of HVEF could effectively reduce the initial bacterial count of pork. Due to the oxygen-enriched MAP, deoxyhemoglobin in pork was converted to oxymyoglobin, reducing the percentage of conversion to metmyoglobin, resulting in the pork being able to effectively maintain the original color of the pork during the refrigeration. The combined results showed that CNE + HVEF+MAP could effectively inhibit the rise of total viable count, total volatile basic nitrogen, and pH in pork, inhibit lipid oxidation of pork, and slow down the deterioration of the color of pork and maintain the original flavor of pork. Therefore, it seems that this all-inclusive approach is more appropriate for extending the chilled shelf life of pork.

Mitigating quality deterioration in chilled pork by combining cinnamaldehyde nanoemulsions and a high-voltage electrostatic field

Cinnamaldehyde nanoemulsion (CNE) was obtained through ultrasonication, using Tween 80 as an emulsifier. The CNE was then applied to chilled pork in conjunction with a high-voltage electrostatic field (HVEF) to mitigate quality deterioration during refrigerated storage. The particle size of CNE ranged from 60 to 150 nm and was positively correlated with the amount of added cinnamaldehyde. The polydispersity index and zeta potential of CNE ranged from 0.25 to 0.30 and - 12 to -11 mV, respectively, indicating a narrow size distribution and stability. The CNE released the odor specific to cinnamaldehyde to pork in the first 4 days of chilling; however, it had little effect on the taste. HVEF pretreatment reduced the initial total viable count (TVC) in pork by 1.14 log cycle. The combination of CNE with HVEF successfully slowed down the loss of moisture, decrease in pH, and accumulation of total volatile basic nitrogen in pork during refrigeration. Furthermore, it mitigated the increase in TVC of pork. Therefore, this integrated method appears to be suitable for extending the shelf life of chilled pork.

Effect of a Chitosan Coating Enriched with an Olive Leaf Extract on the Characteristics of Pork Burgers

Chitosan coatings have been investigated for improving food shelf-life. The addition of an olive leaf extract could enhance its beneficial effect. The aim of this study was to evaluate the effectiveness of an olive leaf extract added to a chitosan coating in delaying deterioration in refrigerated pork burgers without additives packaged under a 40% oxygen and 60% carbon dioxide modified atmosphere. Some general parameters (microbial counts, instrumental color and texture, and lipid and protein oxidation) were measured over the storage of pork burgers without coating (Control), with a chitosan-based coating (Chitosan) and with a chitosan-based coating enriched with an olive leaf extract (Chitoex). The coating impacted the effect of the storage time on most parameters. Both coatings were especially effective at limiting the changes that occur over time in the headspace gases, some texture parameters (hardness, gumminess, and chewiness) and lipid oxidation, although the effect on the microbial counts was weak. Chitoex was more effective than Chitosan at preventing changes in the headspace gases on day 11 and in lipid oxidation on all the sampling days. In conclusion, the Chitoex coating could be useful for prolonging the storage of pork burgers by preventing changes in texture and reducing lipid oxidation.

Preparation and Application of Active Bionanocomposite Films Based on Sago Starch Reinforced with a Combination of TiO2 Nanoparticles and Penganum harmala Extract for Preserving Chicken Fillets

The aim of this study was to develop sago starch-based bionanocomposite films containing TiO₂ nanoparticles and Penganum harmala extract (PE) to increase the shelf life of chicken fillets. First, sago starch films containing different levels of TiO₂ nanoparticles (1, 3, and 5%) and PE (5, 10, and 15%) were prepared. The barrier properties and antibacterial activity of the films against different bacteria strains were investigated. Then, the produced films were used for the chicken fillets packaging, and the physicochemical and antimicrobial properties of fillets were estimated during 12-day storage at 4 °C. The results showed that the addition of nano TiO₂ and PE in the films increased the antibacterial activity against gram-positive (S. aureus) higher than gram-negative (E. coli) bacteria. The water vapor permeability of the films decreased from 2.9 to 1.26 (×10^-11 g/m·s·Pa) by incorporating both PE and nano TiO₂. Synergistic effects of PE and nano TiO₂ significantly decreased the oxygen permeability of the sago starch films from 8.17 to 4.44 (cc.mil/m²·day). Application results of bionanocomposite films for chicken fillet storage at 4 °C for 12 days demonstrated that the films have great potential to increase the shelf life of fillets. The total volatile basic nitrogen (TVB-N) of chicken fillets increased from 7.34 to 35.28 after 12 days, whereas samples coated with bionanocomposite films increased from 7.34 to 16.4. For other physicochemical and microbiological properties of chicken fillets, similar improvement was observed during cold storage. It means that the bionanocomposite films could successfully improve the shelf life of the chicken fillets by at least eight days compared to the control sample.

Chitosan edible coating: a potential control of toxic biogenic amines and enhancing the quality and shelf life of chilled tuna filets

Edible films and coatings offer great potential to support sustainable food production by lowering packaging waste, extending product shelf life, and actively preserving food quality. Using edible coatings containing plant extracts with antioxidant and antibacterial characteristics could help to enhance the quality and shelf life of fish products. In this study, the combination effect of chitosan with beetroot, curcumin, and garlic extracts on biogenic amines (BAs) reduction, biochemical quality [pH, thiobarbituric acid index (TBA), trimethylamine (TMA), and total volatile base (TVB)], shelf life and sensory characteristics of tuna filets was investigated over 14 days of refrigerated storage compared to control (uncoated) samples. The results showed that the coated samples experienced a lower increase in BAs levels than the control samples. Among the treated samples, chitosan incorporated with curcumin (CH-C) showed the highest reduction in BAs formation (1.45 – 19.33, 0.81 – 4.45, and 1.04 – 8.14 mg/kg), followed by chitosan with garlic (CH-G) (1.54 – 21.74, 0.83 – 5.77, and 1.08 – 8.84 mg/kg), chitosan with beetroot extract (CH-B) (1.56 – 31.70, 0.84 – 6.79, and 1.07 – 10.82 mg/kg), and chitosan without extract addition (CH) (1.62 – 33.83, 0.71 – 7.82 and 1.12 – 12.66 mg/kg) compared to control samples (1.62 – 59.45, 0.80 – 11.96, and 1.14 – 20.34 mg/kg) for histamine, cadaverine, and putrescine, respectively. In addition, the rate of increase in pH, TBA, TMA, and TVB of all coated treatments was lower than in the control samples. Sensory evaluation results revealed that chitosan-treated samples incorporated with beetroot, garlic, and curcumin extracts showed good quality and acceptability characteristics. Overall, chitosan edible coatings incorporated with beetroot, garlic, and curcumin extracts reduced the formation of biogenic amine, delayed biochemical deterioration, and extended the shelf life of tuna filets. Among the treated samples, CH-C demonstrated a remarkable superiority in all the studied parameters. Therefore, this study provides a promising strategy for the incorporation of active compounds in edible coatings to improve the quality and safety of foods during storage.

Comparison of antibacterial and antioxidant potentials of pure and nanoemulsified Nepeta pogonosperma essential oil

The current study aimed to investigate the antiradical and antibacterial potential of pure and its nanoemulsified (NNE) Nepeta pogonosperma essential oil (PNE). Antimicrobial activity of the essential oil against two Gram-positive (E. faecalis and B. cereus) and two Gram-negative (M. catarrhalis and K. pneumonia) food-related pathogens during 60-day storage was investigated based on disc diffusion, minimum inhibition concentration (MIC), and minimum bactericidal concentration (MBC). The chemical compounds of Nepeta essential oil were estimated by GC/MS. The physical properties of the nanoemulsion including polydispersity index (PDI), mean particle diameter, and viscosity were also determined. 4aα,7α,7aβ-Nepetalactone (46.31%), 1,8-cineole (23.13%), and (Z)-α-bisabolene (4.01%) were the main compounds of this essential oil. The Nepeta nanoemulsion had a mean droplet diameter of 254.07 nm, PDI of 0.281, and viscosity of 0.887 cP. NNE had stability for up to 60 days. The PNE showed a higher IC50 value than NNE (p < .05). During storage, the antiradical performance of both PNE and NNE was decreased (p < .05). However, emulsification was successful to control this decreasing trend. E. faecalis was the most susceptible bacteria to PNE and NNE, while the lowest inhibition zone was obtained for K. pneumoniae. At the first time, the antibacterial effect of PNE was more than NNE. However, over time nanoemulsion became more successful in maintaining its antibacterial effect. Overall, the incorporation of Nepeta pogonosperma essential oil into a nanoemulsion system can be a promising system to maintain the bioactivity of the essential oil for a longer time.

A Bioactive Chitosan-Based Film Enriched with Benzyl Isothiocyanate/α-Cyclodextrin Inclusion Complex and Its Application for Beef Preservation

A bioactive packaging material based on chitosan (CS) incorporated with benzyl isothiocyanate (BITC) and α−cyclodextrin (α−CD) was fabricated to evaluate its preservative effects on fresh beef stored at 4 °C for 12 d according to the quality analysis. The Fourier-transform infrared (FTIR) spectrum revealed that the major structural moiety of BITC was embedded in the cavity of α−CD, except for the thiocyanate group. FTIR and X-ray diffraction analysis further verified that intermolecular interactions were formed between the BITC−α−CD and CS film matrix. The addition of BITC−α−CD decreased the UV light transmittance of pure CS film to lower than 63% but still had enough transparency for observing packaged items. The CS−based composite film displayed a sustainable antibacterial capacity and an enhanced antioxidant activity. Moreover, the total viable counts, total volatile base nitrogen, pH, thiobarbituric acid–reactive substances, and sensory evaluation of the raw beef treated with the CS−based composite film were 6.31 log colony-forming unit (CFU)/g, 19.60 mg/100 g, 6.84, 0.26 mg/kg, and 6.5 at 12 days, respectively, indicating the favorable protective efficacy on beef. These results suggested that the fabricated CS−based composite film has the application potential to be developed as a bioactive food packaging material, especially for beef preservation.