Search

The experiment took the broccoli (Brassica oleracea var. italica) as the research object, 1-methylcyclopropene (1-MCP), mustard essential oil (MEO) and 1-MCP combined MEO (1-MCP+MEO) were used to treat fresh green broccoli. The effects of physiological and biochemical indexes such as sensory quality, relative conductivity, chlorophyll, vitamin C and malondialdehyde (MDA) content on the quality of broccoli were investigated during storage. The result showed that with the increase of storage time, all groups of preservative treatments could effectively maintain the quality of broccoli during storage, among which 1-MCP+MEO treatment had the best storage effect on broccoli, effectively maintained the appearance of broccoli, avoided yellows and mildew, and slowed down the chlorophyll content and vitamin C degradation rate and made the chlorophyll content of broccoli always higher than that of other treatment groups. 1-MCP+MEO inhibited the increase of relative conductivity and MDA content in broccoli. On the 28th day of storage, the relative conductivity and MDA of the combined treatment group were 14.94% and 9.1 µmol/g, respectively, which were 43.1% and 27.6% lower than that of the control group respectively, and there was a significant difference (P<0.05), so that the cell integrity of the broccoli was maintained and the senescence of the broccoli was inhibited. After 28 days of storage, 1-MCP+MEO treatment group could effectively reduce the decrease of total phenol and total flavonoid contents, and combined treatment was 51.9% higher than that of control group, and total flavonoid content was 38.4% higher than that of control group. In addition, the activity of polyphenoloxidase (PPO) and peroxidase (POD) related to enzymatic browning was significantly inhibited, and the activity of PPO and POD were 23.6% and 48.1% lower than that of control group, respectively. Significantly lowered than control group (P<0.05). This study aims to provide a theoretical basis for the development of broccoli preservation technology and a new idea for the research and development of preservatives. [ABSTRACT FROM AUTHOR]

The appeal for environment friendly films with bioactive components to replace synthetic plastic packaging has been increasing in recent years. In this study, ginger essential oil (GEO) nanoemulsion at different levels (0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) were incorporated into fish sarcoplasmic protein (FSP) and chitosan (CH) blend films to evaluate the physical, mechanical, antioxidant, and thermal properties. The water distribution state of films was also determined by NMR transverse relaxation (T2) measurements. The tensile strength (TS) of samples was significantly reduced with increasing GEO nanoemulsion contents (p < 0.05), while the value of elongation at break (EAB) was the highest when the film with 1.0% GEO nanoemulsion. The addition of GEO nanoemulsion enhanced the water barrier properties and affected the water distributions of films, but had negative effects on thermal degradation of films. Scanning electric microscope (SEM) demonstrated the different microstructure at varied levels of GEO nanoemulsion and Fourier transform infrared (FTIR) spectroscopy gave the detailed information about the interactions at molecular level. These results revealed that FSP blended with CH was excellent film-forming material and mixing defined amount of GEO nanoemulsion into film-forming solution enhanced the physical and antioxidant properties of films. [ABSTRACT FROM AUTHOR]

Active films with essential oils have attracted more attention in recent years. In order to improve the solubility and stability of ginger essential oil (GEO) in film forming solutions, GEO coarse emulsion and nanoemulsions were prepared named CGEO (z‐average = 799.53 nm), NGEO‐1 (z‐average = 114.71 nm) and NGEO‐2 (z‐average = 59.30 nm), respectively. And the effect of concentration (0.5% and 1.0% v/v) and particle sizes of GEO emulsions on the physiochemical and preservation properties of fish sarcoplasmic protein and chitosan blend based edible films were studied in this study. The elongation at break significantly (p <.05) increased after adding GEO emulsions, and the light transmittance, water vapor permeability and water solubility were the lowest when NGEO‐2 was incorporated into films. The antioxidant and antimicrobial activities of films were concentration‐dependent. Furthermore, all the films were applied into packaging red sea breams fillets, and the results of total viable counts, pH and thiobarbituric acid demonstrated that SP‐CH films with GEO emulsions, especially nanoemulsions obviously prolonged the shelf‐life of fillets during 4°C. Practical Applications: In recent years, the research about incorporating essential oils into edible films to prepare active edible films due to their antimicrobial and antioxidant properties have been more documented. In this study, fish sarcoplasmic protein and chitosan were chosen as film‐forming materials to prepare active films with ginger essential oil emulsions. The physicochemical, mechanical, optical properties of films showed that the films have the basic characteristics as food packaging materials. The releasing and antioxidant property of films indicated that the active films have a potential application in packaging food which was easy oxidized. The basic properties of films combined with oxidation indicators (total viable count, pH and thiobarbituric acid reactive substances) would provide the scientific basis for developing active films and their application for food packaging, such as seafood, meat, fruits and vegetables. [ABSTRACT FROM AUTHOR]

Abstract: The effects of chitosan coating enriched with lemon and thyme essential oils on the physicochemical, microbiological, and quality changes of grass carp fillets during 2 °C storage were determined during 16 days of storage. The pH, total volatile basic nitrogen, thiobarbituric acid reactive substances, color, texture, sensory quality, total viable count, psychrotrophic bacteria, pseudomonads, Shewanella putrefaciens, Enterobacteriaceae, and lactic acid bacteria counts were analyzed. The results indicated that chitosan coating (1.5%) incorporated with lemon or thyme essential oils (0.5%) maintained higher hardness and retarded the oxidation of lipid and protein. The most effective treatment was chitosan coating (1.5%) enriched with lemon and thyme essential oils (0.25 and 0.25%) together, which maintained the color and texture properties, and reduced the microorganisms counts. The results suggested that the synergized use of lemon and thyme essential oils increased the efficiency of chitosan coating, maintained fish fillets quality and extended its shelf life to 16 days. Practical applications: The commercial value of fresh fish fillets is lost in a few days. Many methods have been used to inhibit the spoilage caused by microorganisms, retard the degradation of protein, and extend the shelf life of fish fillets. As an alternative to chemical and synthetic preservatives, many studies are currently focused on using natural products to improve the quality of fish products. This study reports that chitosan coating incorporated with lemon and thyme essential oils together is a promising edible coating for use in commercial applications for prolonging the shelf life of fish fillets. [ABSTRACT FROM AUTHOR]

Several naturally occurring essential oils were evaluated for their effectiveness in maintaining post-mortem quality and extending shelf life of red drum ( Sciaenops ocellatus ). Fresh fish fillets were treated with 4 μl/L clove, cumin and spearmint oils at 10 °C for 2 h and the hardness, pH value, K -value, TCA-soluble peptides, sensory evaluation, biogenic amines and microbiological characteristics determined. The results showed that the fillets treated with spearmint oil significantly maintained tissue hardness when compared to the control. Moreover, spearmint essential oil treatment significantly delayed protein degradation and nucleotide breakdown. The essential oil treatment also inhibited the microbiological properties throughout the storage periods. All the treatments were effective in retarding fish sensory deterioration, exhibited a positive effect, causing low biogenic amines content, especially histamine, putrescine, cadaverine. These results indicate that essential oil treatment might be a potential application for extending the shelf life and maintaining the quality of the red drum. [ABSTRACT FROM AUTHOR]

Antimicrobial activity of essential oils is widely known, but their application to fish preservation is already limited. The objective was to evaluate the microbiological characteristics and quality changes in turbot ( Scophthalmus maximus) fillets with essential oil fumigation treatments over 20 days stored at 2 ± 1 °C. The turbot fillets were fumigated with a series of concentrations (1, 4, and 8 μL/L) of essential oils of clove, cumin, and spearmint. Changes in the color, texture profile analysis (TPA), peroxide value (PV), 2-thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), microbial characteristics (total viable count, psychrotrophic count, pseudomonads, Shewanella putrefaciens, Enterobacteriaceae, and lactic acid bacteria count) were measured. The results showed the turbot fillets from the control group were the first (day 10) to indicate signs of degradation reaching rejection threshold values for all evaluated parameters. All essential oils could inhibit the oxidation of turbot fillets, and the most effective essential oil was spearmint oil. Fumigated with 4 μL/L spearmint oil maintained the color and texture, retarded the lipid and protein oxidation, and reduced the microorganism counts. Therefore, post-mortem essential oil fumigation treatment has positive effects on improving the quality of refrigerated turbot fillets. [ABSTRACT FROM AUTHOR]

This research was conducted to assess the structure, mechanical, barrier and optical properties of three edible composite films based on chitosan nanoparticles. Films containing cinnamon-perilla essential oil (C-PEO) Pickering nanoemulsion had denser structure and better mechanical properties. In addition, films with anthocyanidins exhibited enhanced antioxidant activity. The results showed that both Pickering nanoemulsion and anthocyanidins could improve some properties of edible composite film based on chitosan nanoparticles. Finally, preservation experiments were carried out. Analysis of storage quality indices (sensory evaluation, microbiological analyses, pH, total volatile basic nitrogen, thiobarbituric acid values, color and texture) revealed the shelf life of fillets wrapped in three kinds of composite film was extended to 6–8 days. The preservation effect of plant essential oil compound anthocyanidin edible film for fillet was the best and anthocyanidins compound chitosan nanoparticles edible film was the best in appearance of protection. • Three novel chitosan nanoparticles films were prepared and characterized. • Physical properties of the film improved with adding Pickering nano-emulsion. • The effect of three kinds of edible film on the preservation of fresh fillets. • Composite film delayed lipid oxidation and proteolysis in fresh fillets. [ABSTRACT FROM AUTHOR]

In this study, cinnamon-perilla essential oil (C-PEO) Pickering nanoemulsions were prepared using collagen as an emulsifier, and the effects of Pickering nanoemulsion addition on the structure and properties of anthocyanidin/chitosan nanocomposite-based edible films were investigated. The compatibility of the anthocyanidin/chitosan nanocomposite-based edible films and C-PEO Pickering emulsions were further analyzed by fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. As results, Pickering nanoemulsions containing 1% (v/v) C-PEO (C-PEO-2) had the smallest droplet size (11.84 nm). The edible film exhibited better physical properties (i.e., mechanical, water vapor permeability and thermal stability) after adding C-PEO-2. Furthermore, the hydrophobicity and the antioxidant activity of the film were enhanced after incorporating with C-PEO. Finally, the application of the films to chilled (4) fish fillet preservation was also conducted, wrapping with the edible film was effective in controlling quality changes in fish fillets with lower TVB-N and TBAR values during 8 days of chilled storage. Keywords: Cinnamon-perilla essential oil; Pickering nanoemulsions; Anthocyanidin; Chitosan nanoparticles; Fillet preservation. [Display omitted] • Novel edible film based on chitosan nanoparticles was prepared and characterized. • There was no add chemical emulsifier into cinnamon-perilla essential oil. • The properties of the film improved with adding Pickering nanoemulsion. • The shelf life of fillets was extended when packing by the edible film. [ABSTRACT FROM AUTHOR]