Silane-interfacial toughening of nanocellulose/starch composite films: One-pot engineering for anti-aging food packaging

Single-use synthetic plastics that are used as food packaging is one of the major contributors to environmental pollution. Hence, this study aimed to develop a biodegradable edible film incorporated with Limosilactobacillus fermentum. Investigation of the physical and mechanical properties of chitosan (CS), sodium caseinate (NaCas), and chitosan/sodium caseinate (CS/NaCas) composite films allowed us to determine that CS/NaCas composite films displayed higher opacity (7.40 A/mm), lower water solubility (27.6%), and higher Young's modulus (0.27 MPa) compared with pure CS and NaCas films. Therefore, Lb. fermentum bacteria were only incorporated in CS/NaCas composite films. Comparison of the physical and mechanical properties of CS/NaCas composite films incorporated with bacteria with those of control CS/NaCas composite films allowed us to observe that they were not affected by the addition of probiotics, except for the flexibility of films, which was improved. The Lb. fermentum incorporated composite films had a 0.11 mm thickness, 17.9% moisture content, 30.8% water solubility, 8.69 A/mm opacity, 25 MPa tensile strength, and 88.80% elongation at break. The viability of Lb. fermentum after drying the films and the antibacterial properties of films against Escherichia coli O157:H7 and Staphylococcus aureus ATCC 29213 were also evaluated after the addition of Lb. fermentum in the composite films. Dried Lb. fermentum composite films with 6.65 log10 CFU/g showed an inhibitory effect against E. coli and S. aureus (0.67 mm and 0.80 mm inhibition zone diameters, respectively). This shows that the Lb.-fermentum-incorporated CS/NaCas composite film is a potential bioactive packaging material for perishable food product preservation.

Poly-(lactic acid) composite films comprising carvacrol and cellulose nanocrystal–zinc oxide with synergistic antibacterial effects

Ultraviolet shielding and antibacterial dialdehyde cellulose-polyvinyl alcohol (PVA) composite packaging film for strawberry preservation.

To ensure food and environmental safety, biodegradable packaging materials from various natural polymers are being used to preserve the high quality of foods and to increase their shelf life in addition to environmental safety in terms of biodegradability. However, these natural polymers have some disadvantages in functionality. There are many ways to improve functionality, one such way is the addition of essential oils. Therefore, this research work was done to investigate the effectiveness of four diverse essential oils (EOs), namely, lemon‐grass oil (LGO), tea‐tree oil (TTO), thyme oil (THO), and basil oil (BO) in chitosan‐based composite films. The chitosan as a biopolymer, polyvinyl alcohol (PVA) as a compatibilizer, and four different essential oils@0.3% were blended to form composite food packaging films. These nanofilms had better mechanical strength, elasticity, and film thickness. Thermal stability and change in the weight of chitosan alone and composite films were determined by thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) was used to analyze the change in film surface morphology. The Fourier transform infrared (FTIR) spectrum of the base polymer exhibits characteristic peaks at 3400 cm−1 indicating the occurrence of hydrogen‐bonded OH groups, and peaks at 1500–1600 cm−1 corresponding to the amide II band and CO stretch of the acetyl group. Whereas TGA results confirmed the thermal stability of PVA and EO blended films compared to chitosan alone films. The biodegradability of antimicrobial chitosan‐based films exhibited around 15%–19% percentage of degradation in PVA blended films whereas chitosan alone degraded up to 32% after 30 days. Water vapor transmission was high in chitosan alone film (1.9%) and 0.25% in PVA/EO blended films displaying enhancement in hydrophobic qualities of the developed films due to change in hydrophobicity by EO addition. The chitosan and PVA alone films were transparent whereas EO blended films exhibited yellow coloration and became less transparent due to the oil droplets dispersion in films. The shelf life of tomato, bread, and paneer was better in lemongrass and tea tree oil‐incorporated films during storage.

Recent research progress on locust bean gum (LBG)-based composite films for food packaging

Emerging starch composite nanofibrous films for food packaging: Facile construction, hydrophobic property, and antibacterial activity enhancement

Cellulose acetate (CA) membranes have been widely used as food packaging materials as well as reverse osmosis systems. This study presents the manufacturing of composite CA film with antibacterial properties which is essential for CA film applications in the industry. N‐Halamine precursor of polymethacrylamide‐modified nano‐crystalline cellulose particles (NCC‐PMAMs) were prepared and incorporated into CA film. The composite films with intercalated structure were formed via a solvent‐casting technique. After chlorination, the composite film CA/NCC‐PMAM‐Cl‐1.0 with 1.82 × 1016 atoms/cm2 covalently bonded chlorine showed excellent antibacterial properties by inactivating 6.04 logs of Staphylococcus aureus and 6.27 logs of Escherichia coli within 10 and 5 min, respectively. According to X‐ray diffraction spectra, NCC‐PMAMs behaved as a facilitator for film crystallization. The mechanical strength of the composite film also increased compared with that of pure CA film. However, the composite film became brittle and the maximum decomposition temperature decreased slightly. Preliminary data of in vitro cytocompatibility evaluation indicate that the film is not toxic and has potential use in food packaging. Copyright © 2016 John Wiley & Sons, Ltd.

PurposeThe physical, biomechanical and chemical properties of the composite biodegradable films are examined by their chemical composition, structure, processing conditions and economics. Therefore, the purpose of the study was to develop standard composite biodegradable films by optimizing the process (drying time and temperature) and composition (whey protein concentrate; WPC and sodium alginate; SA).Design/methodology/approachComposite WPC–SA films were developed using the Box–Behnken design of response surface methodology (RSM), with individual and interactive effects of process variables on the response variables (quality characteristics). Three independent factors at three different levels (WPC: 5–7 g, SA: 0.1–0.5 g and drying temperature: 35°C–45°C) were evaluated for their effects on physical and biomechanical properties, namely, thickness, penetrability, moisture content, water vapor transmission rate (WVTR), density, solubility, transmittance and color variables. The results were analyzed using ANOVA. For each response, second-order polynomial regression models and resulting equations were developed.FindingsThe response surface plots were constructed for representing a relationship between process parameters and responses. All responses were optimized as the best and desired, namely, thickness (180 µm), penetrability (7.63 N), moisture (28.05%), WVTR (1.87 mg/m2t), solubility (36.12%), density (1.33 g/ml), transmittance (40.55%),L* value (52.50),a* value (0.35) andb* value (13.70). The regression models exhibited “good fit” of experimental data with a high coefficient of determination. A close agreement was found between experimental and predicted values.Practical implicationsThese biodegradable films can be promisingly used in the food packaging system without the problem of disposability.Originality/valueThe composite films with proteins and polysaccharides can be developed, which have improved physical and biomechanical properties.

ABSTRACTConventional food packaging plastics are difficult to degrade under natural conditions, causing long‐lasting environmental harm. With the aim of addressing this problem, this study develops a novel biodegradable composite food packaging film based on polybutylene adipate‐terephthalate (PBAT) and polyurethane (PU). MOF‐5 nanoparticles are prepared via the ambient temperature precipitation method and modified with gallic acid (GA). PBAT/PU/GA@MOF‐5 composite films are fabricated by the solvent casting method. The findings demonstrate that the introduction of GA@MOF‐5 enhances the compatibility between PBAT and PU and reduces phase separation; therefore, it augments the mechanical performance of the resultant composite films. These composite films manifest excellent mechanical, thermal degradation, and antioxidant properties, performing remarkably in apple freshness tests. Furthermore, the incorporation of GA@MOF‐5 endows the films with significant antimicrobial activity, showing restraint on the proliferation of both Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). This study offers an innovative idea for biodegradable food packaging materials design and expands the application prospect of the PBAT/PU composite system in the food packaging field.

Development and characterization of fish myofibrillar protein/chitosan/rosemary extract composite edible films and the improvement of lipid oxidation stability during the grass carp fillets storage

In this study, keratins were extracted from pig nail waste through the reduction method using L-cysteine as a reductant. Curcumin was successively incorporated in a mixed solution including keratin, gelatin, and glycerin to prepare different kinds of keratin/gelatin/glycerin/curcumin composite films. The morphology of the keratin/ gelatin/glycerin/curcumin composite films were examined using scanning electron microscopy. The structures and the molecular interactions between curcumin, keratin, and pectin were examined using Fourier transform infrared spectroscopy and X-ray diffraction, and the thermal properties were determined through thermogravimetric analysis. The tensile strengths of keratin/gelatin/glycerin/curcumin and keratin/gelatin/curcumin composite films are 13.73 and 12.45 MPa, respectively, and their respective elongations at break are 56.7% and 4.6%. In addition, compared with the control group (no film wrapped on the surface of tomato), the ratio of weight loss of the keratin (7.0%)/gelatin (10%)/glycerin (2.0%)/curcumin (1.0%) experimental groups is 8.76 ± 0.2%, and the hardness value of the tomatoes wrapped with composite films is 11.2 ± 0.39 kg/cm3. Finally, the composite films have a superior antibacterial effect against Staphylococcus aureus and Escherichia coli because of the addition of curcumin. As the concentration of curcumin reaches 1.0%, the antibacterial activity effect of the film is significantly improved. The diameter of the inhibition zone of E. coli is (12.16 ± 0.53) mm, and that of S. aureus is (14.532 ± 0.97) mm. The multifunctional keratin/gelatin/glycerin/curcumin bioactive films have great potential application in the food packaging industry.

Multifunctional composite polyvinyl alcohol film reinforced with polymeric ionic liquid-modified cellulose nanocrystals for multimodal bacteriostatic food packaging.

Aralia continentalis Kitagawa and ginseng are both perennial herbs of Araliaceae. The study aimed to investigate the composite packaging films with better fresh-keeping ability. The different mass concentrations of Aralia continentalis Kitagawa root extract (ARE) 0.05%, 0.10%, and 0.15% (v/w) were compounded with chitosan (CH) to make composite packaging films. Food-based composite film, its thickness, density, water contact angle (WCA), oxygen barrier properties (OP), solubility, swelling, transparency, water vapor permeability (WVP), and other physical properties, as well as tensile strength (TS), elongation at break (EAB), Young’s modulus (YM), and the mechanical properties were measured, and the oxidation resistance, thermal properties, and biodegradability were also evaluated, and the structure was analyzed by infrared spectroscopy. The results showed that when the ARE content in the film was increased from 0.05 to 0.15 mg·mL−1, high antioxidant capacity of the CH/ARE film was exhibited (the DPPH and ABTS+ free radical scavenging rate was increased), and the thickness, density, swelling degree, solubility, TS, EAB, and YM of the CH/ARE composite film increased, while WCA, OP, WVP, transparency, and biodegradability were slightly reduced. We had noticed that with the increase in the ARE content, the surface microstructure in CH/ARE film changed significantly, indicating the good compatibility between CH and ARE. In summary, as a natural active substance, ARE can be combined with CH to form films, and the packaging film made can effectively improve the performance of the composite film.

Multifunctional silver/ε-polylysine/diethyl ferulate composite films with improved anti-UV and antibacterial properties for food packaging.

Structure and properties of starch/chitosan food packaging film containing ultra-low dosage GO with barrier and antibacterial