Influence of anise (Pimpinella anisum L.) essential oil on the microbial, chemical, and sensory properties of chicken fillets wrapped with gelatin film.

The present study aimed to develop a novel active edible film based on gelatin incorporated with 0, 0.3, 0.6, and 0.9% w/w anise essential oil as a natural preservative and investigate the shelf life extension potential of chicken fillets during 12 days of refrigerated storage. The chicken fillets were wrapped with the essence-free and anise essential oil-loaded gelatin films, and microbial counts, chemical and sensory tests were surveyed during chilled storage. Results showed that aerobic mesophilic bacteria and Pseudomonas spp counts significantly decreased at all levels of anise essential oil during the first week of storage, while psychrotrophs, yeasts, and molds numbers began to reduce at concentrations of 0.6 and 0.9% from day 6. The using of anise essential oil caused a significant decrease of chemical parameters of chicken fillets, and the values of pH, peroxide, thiobarbituric acid reactive substance, and total volatile basic-nitrogen reached from 7.42, 5.7 meq/kg, 2.21 mg malondialdehyde/kg, and 24.94 mg N/100 g for the essence-free wrapped samples to 4.8, 6.35 meq/kg, 1.73 mg malondialdehyde/kg, and 18.78 mg N/100 g for the ones wrapped with 0.9% anise essential oil-loaded gelatin films at the end of storage day. In conclusion, application of gelatin films loaded with 0.6 and 0.9% anise essential oil can be advised for wrapping chicken fillets to prolong the shelf life for at least one week.

Fabrication and characterization of CMC-based nanocomposites reinforced with sodium montmorillonite and TiO2 nanomaterials.

In this study, a novel carboxymethyl cellulose (CMC)-based ternary nanocomposite films containing sodium montmorillonite (Na-MMT) (1, 3 and 5% wt) and titanium dioxide (TiO2) (1, 3 and 5% wt) nanoparticles (NPs) were made via casting method. The results showed that addition of NPs decremented water vapor permeability of the films up to 39% and 50% by adding Na-MMT, and Na-MMT + TiO2, respectively, while moisture content, density and glass transition temperature incremented slightly. The nanoclays amplified resistance of the nanocomposites against tensile stress and Young's modulus (YM) of the films at the expense of elongation at break. A synergistic effect of NPs on moisture uptake reduction (≈ 40%) of films was observed. Nano-TiO2 was strongly effective in UV-light blocking (The films containing 5% TiO2 removed more than 99% of UV and more than 98% of visible lights). The interactions, crystallinity and morphology of the nanocomposites were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Development of hydrogen bonds between the hydroxyl groups of CMC and nanoparticles was indicated by FT-IR spectroscopy. Conforming to the XRD analysis, clay nanolayers organized an intercalated structure in the nanocomposites, whereas a limited agglomeration of TiO2 nanoparticles led to increment of films crystallinity. SEM micrographs showed well-dispersed Na-MMT and TiO2 NPs through the films surface especially at low concentrations. In conclusion, although the films loaded with nanoclays exhibited better properties than the control film, inclusion of TiO2 more improved the functional characteristics of them and extended the potential as a biodegradable packaging.

Physical and mechanical properties of hybrid montmorillonite/zinc oxide reinforced carboxymethyl cellulose nanocomposites.

In this research, a novel carboxymethyl cellulose (CMC)-based nanocomposite films containing sodium montmorillonite (MMT) (5%wt) and zinc oxide (ZnO) (1, 2, 3 and 4%wt) nanoparticles (NPs) were fabricated via casting method. The results revealed that addition of NPs decreased water vapor permeability of the films by about 53%, while moisture content, density and glass transition temperature increased. The nanomaterials enhanced resistance of the nanocomposites against tensile stress at the expense of elongation at break. Nano-ZnO was very effective than nanoclay in UV-light blocking (99% vs. 60%) associated with sacrificing the films transparency. Formation of hydrogen bonds between the hydroxyl groups of CMC and MMT was evidenced by FTIR spectroscopy. According to the XRD analysis, clay nanolayers formed an exfoliated structure in the nanocomposites, whereas ZnO NPs raised crystallinity. SEM micrographs showed well-dispersed MMT and ZnO NPs through the films surface. Antibacterial test showed that vulnerability of Gram-positive S. aureus toward ZnO NPs was more than that of Gram-negative E. Coli. In conclusion, simultaneous incorporation of MMT and ZnO NPs improved the functional characteristics of CMC film and extended the potential for food packaging applications.

Use of gelatin and gum Arabic for encapsulation of black raspberry anthocyanins by complex coacervation.

Protein-polysaccharide interactions offer opportunities for designing the new functional foods with applications in the food and pharmaceutical industries. In this work, we microencapsulated black raspberry water extracts by double emulsion technique prior to complex coacervation using gelatin and gum Arabic to diminish the instability of their anthocyanins (ANCs) as water soluble compounds, particularly under harsh processing and storage conditions. Subsequently, optical microscopy, moisture, hygroscopicity, solubility, particle size, loading capacity, zeta potential, color parameters (L*, a*, b*, C, H° and TCD), stability, Fourier transform infrared spectroscopy (FTIR), and thermal behavior were evaluated. The microcapsules presented the lower moisture, hygroscopicity and solubility values as comparing the free form of ANCs. They showed the average sizes ranging from 35.34±3.21 to 80.22±5.21µm and high loading capacity (29.67±0.66-38.54±0.08%). According to the HPLC results, the selected method significantly increased the stability of ANCs up to 23.66% after 2 months of storage at 37±2°C. FT-IR spectra confirmed the negative zeta potential values of microcapsules and the occurrence of coacervation process. DSC results evidenced the thermostability of microcapsules. Furthermore, the selected optimal microcapsules revealed intense red color over the time of storage, implying the effectiveness of the method chosen to preserve anthocyanins.