Poly (butylene adipate-co-terephthalate)/magnesium oxide/silver ternary composite biofilms for food packaging application

Pedalium murex plant-based bioplasticizer reinforced polylactic acid films: A promising approach for biodegradable fruit packaging applications

The most likely materials for use in packaging are plastics. A lot of synthetic polymers are harming the environment. A plasticizer is required for all polymers to improve their characteristics and workability. The plasticizers come in liquid form and are also derived from fossil fuels, which are harmful to the environment. Producing functional and affordable biopolymer for packaging applications is a difficult task nowadays. The preparation of biofilm for packaging using biopolymer and bioplasticizer is the main aim of this work. The biopolymer poly L-lactic acid (PLA) is used, and the bio plasticizer is extracted from Pedalium murex plant. Chemical and mechanical methods are used to extract the plasticizer. Plasticization of polylactic acid biopolymer was done using the extracted plasticizer at additions of 1 %, 2 %, 3 %, 4 %, and 5 %. FT-IR spectroscopy, X-ray diffraction spectroscopy, and surface roughness values are used to characterise the prepared biofilms. Scanning electron spectroscopy pictures are utilised to evaluate the morphological orientation of the biofilms. Strawberries packed with biofilms are used to evaluate the barrier properties of biofilms using UV spectroscopy analysis. Thermal degradation behaviour is investigated using thermo gravimetric analysis. We examined the mechanical characteristics, such as tensile strength, elongation modulus, and elongation break percentage. The plasticizing effect of the plasticizer raises the elongation break percentage while decreasing the tensile strength and modulus. For 2 % plasticizer addition the elongation break increases and the tensile not much affected. To demonstrate biodegradability and microbial resistance, the soil degradation behaviour and antimicrobial activities were examined.

Natural lignocellulosic biomass structure inspired CNF/Lignin/PBAT composite film with thermoplastic, antibacterial and UV-blocking abilities

The development of a thermoplastic, biodegradable composite material to replace conventional polymers derived from petroleum was the main area of concentration. Herein, a method for preparing antibacterial, UV-blocking and degradable CNF/Lignin/PBAT composite films (CLP) using cellulose nanofibrils (CNF), lignin, and Poly (butylene adipate-terephthalate) (PBAT) as raw materials by solution casting method was described. With the adding of PBAT, the thermal stability, thermoplastic, mechanical properties were enhanced by improving the compatibility between components. The maximum tensile strength of CLP could reach 189.72 MPa, which increased 25.5 % compared to CNF/Lignin film. The average initial decomposition temperature could reach 321 °C, which was much higher than that of CNF and lignin. At the same time, its good heat-sealing performance made it suitable for practical use. Meanwhile, the composite films had excellent UV resistance and could block over 95 % of UV light. The antibacterial results indicated that the films had a good inhibitory effect on E. coli and S. aureus, with a maximum inhibitory ring diameter of 5.56 and 6.36 mm. In addition, the composite film also had excellent barrier capability to liquid and gas. The prepared film had potential to produce flexible packing, industrial compositing and biomedical fields.

Poly(butylene adipate-co-terephthalate)/Polylactic Acid/Tetrapod-Zinc Oxide Whisker Composite Films with Antibacterial Properties

Biodegradable composite films comprising of poly(butylene adipate-co-terephthalate) (PBAT), polylactic acid (PLA), and tetrapod-zinc oxide (T-ZnO) whisker were prepared by a melt-extrusion and blow molding process. The effect of the incorporation of the T-ZnO whisker (1 to 7 wt.%) in the PBAT/PLA blend film was studied systematically. The composite films with an optimal T-ZnO whisker concentration of 3 wt.% exhibited the highest mechanical (tensile strength ~32 MPa), rheological (complex viscosity~1200 Pa.s at 1 rad/s angular frequency), and gas barrier (oxygen permeability~20 cc/m2·day) properties, whereas the composite films with 7 wt.% T-ZnO whiskers exhibited the highest antibacterial properties. The developed composite films can find potential application as antibacterial food packaging materials.

Recent progress in PBAT-based films and food packaging applications: A mini-review

Bioplastics are a promising alternative to non-biodegradable plastics. One of these bioplastics, PBAT (polybutylene adipate co-terephthalate), is a polyester-based bioplastic commonly used to manufacture flexible packaging films. PBAT-based films have high flexibility but relatively low strength compared to other bioplastics. The strength of PBAT films can be improved by blending them with other fillers/polymers. Additionally, the functionality of PBAT films can be enhanced by incorporating bioactive functional fillers. The physical and functional properties of PBAT films produced by adding active ingredients provide functionality and are a good alternative to non-degradable petrochemical-based plastics. The PBAT-based functional films protect food and improve packaged foods' quality and life span. Thus, this review provides recent advances in PBAT-based films and their use in active food packaging applications. After briefly describing the different fabrication methods of PBAT films, various important physical and functional properties and biodegradability are comprehensively discussed. PBAT-based active packaging film in real-time food packaging is also briefly covered. Through this review, more attention is expected to be focused on research on PBAT-based biodegradable active food packaging.

Modified magnesium oxide/silver nanoparticles reinforced poly (butylene succinate-co-terephthalate) composite biofilms for food packaging application

MgO/Ag nanoparticles (NPs) were surface-modified with titanate coupling agent titaniumtriisostearoylisopropoxide (NDZ-130). A new antibacterial biofilm for food packaging was synthesized by combining the modified MgO/Ag NPs with poly (butylene succinate-co-terephthalate) (PBST). The modification improved the compatibility between the MgO/Ag NPs and the PBST matrix. The effects of the modified MgO/Ag NPs on biofilm mechanical, barrier, thermal, antibacterial and food preservation properties were evaluated. Compared with the PBST/MgO/Ag composite film, the modified PBST/MgO/Ag composite film showed an increase in tensile strength (TS) of 8.71% and elongation at break (EB) of 16.66%, additionally decreasing water vapor permeability (WVP) by 42.86%. The composite film also exhibited over 95% inhibition of Staphylococcus aureus and Escherichia coli. The modified PBST/MgO/Ag composite film avoided microbial contamination and preserved cherry tomatoes while maintaining moisture and firmness for six days. All results indicated that the prepared biofilms have a high potential for use as food packaging films.

Insight on recently discovered PET polyester-degrading enzymes, thermostability and activity analyses

The flexibility and the low production costs offered by plastics have made them crucial to society. Unfortunately, due to their resistance to biological degradation, plastics remain in the environment for an extended period of time, posing a growing risk to life on earth. Synthetic treatments of plastic waste damage the environment and may cause damage to human health. Bacterial and fungal isolates have been reported to degrade plastic polymers in a logistic safe approach with the help of their microbial cell enzymes. Recently, the bacterial strain Ideonella sakaiensis (201-F6) was discovered to break down and assimilate polyethylene terephthalate (PET) plastic via metabolic processes at 30 °C to 37 °C. PETase and MHETase enzymes help the bacterium to accomplish such tremendous action at lower temperatures than previously discovered enzymes. In addition to functioning at low temperatures, the noble bacterium's enzymes have amazing qualities over pH and PET plastic degradation, including a shorter period of degradation. It has been proven that using the enzyme PETase, this bacterium hydrolyzes the ester linkages of PET plastic, resulting in production of terephthalic acid (TPA), nontoxic compound and mono-2-hydroxyethyl (MHET), along with further depolymerization of MHET to release ethylene glycogen (EG) and terephthalic acid (TPA) by the second enzyme MHETase. Enzymatic plastic degradation has been proposed as an environmentally friendly and long-term solution to plastic waste in the environment. As a result, this review focuses on the enzymes involved in hydrolyzing PET plastic polymers, as well as some of the other microorganisms involved in plastic degradation.

Essential characteristics improvement of metallic nanoparticles loaded carbohydrate polymeric films - A review

Petroleum-based films have contributed immensely to various environmental issues. Developing green-based films from carbohydrate polymers is crucial for addressing the harms encountered. However, some limitations exist on their property, processibility, and applicability that prohibit their processing for further developments. This review discusses the potential carbohydrate polymers and their sources, film preparation methods, such as solvent-casting, tape-casting, extrusion, and thermo-mechanical compressions for green-based films using various biological polymers with their merits and demerits. Research outcomes revealed that the essential characteristics improvement achieved by incorporating different metallic nanoparticles has significantly reformed the properties of biofilms, including crystallization, mechanical stability, thermal stability, barrier function, and antimicrobial activity. The property-enhanced bio-based films made with nanoparticles are potentially interested in replacing fossil-based films in various areas, including food-packaging applications. The review paves a new way for the commercial use of numerous carbohydrate polymers to help maintain a sustainable green environment.

Preparation and Performance of Biodegradable Poly(butylene adipate-co-terephthalate) Composites Reinforced with Novel AgSnO2 Microparticles for Application in Food Packaging

Biodegradable composites with antimicrobial properties were prepared with microparticles of silver stannate (AgSnO₂) and poly(butylene adipate-co-terephthalate) (PBAT) and tested for applications in food packaging. The PBAT matrix was synthesized and confirmed by ¹H-nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction (XRD). Ultrasonic and coprecipitation methods were used to synthesize AgSnO₂. A two-step mixing method and a solvent cast technique were utilized to fabricate the PBAT composites (different weight % of AgSnO₂) for packaging foods. Attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, XRD, and scanning electron microscopy were used to investigate the formation, structure, and size of the composites. Thermogravimetric analysis and differential thermal calorimetry were used to examine the PBAT/AgSnO₂ composites. The best characteristics are exhibited in 5.0 wt. % AgSnO₂ loaded PBAT composite. The tensile strength, elongation at break, water vapor transmission rate, and oxygen transmission rate were 22.82 MPa, 237.00%, 125.20 g/m²/day, and 1104.62 cc/m²/day.atm, respectively. Incorporating AgSnO₂ enhanced the hydrophobicity of the PBAT materials as evaluated by the water contact angle. The 5.0 wt. % AgSnO₂/PBAT film shows a favorable zone of inhibition against the bacteria pathogens S. aureus and E. coli, according to an evaluation of its antimicrobial activity. The weight loss of 5% AgSnO₂/PBAT film was 78.4% after eight weeks in the natural soil environments. In addition, the results of food quality studies recommend that AgSnO₂/PBAT (5.0 wt. %) film had a longer food shelf life than the neat PBAT and commercial, increasing it from one to 14 days for carrot vegetables.

Recent advances in biobased and biodegradable polymer nanocomposites, nanoparticles, and natural antioxidants for antibacterial and antioxidant food packaging applications

Inorganic nanoparticles (NPs) and natural antioxidant compounds are an emerging trend in the food industry. Incorporating these substances in biobased and biodegradable matrices as polysaccharides (e.g., starch, cellulose, and chitosan) and proteins has highlighted the potential in active food packaging applications due to more significant antimicrobial, antioxidant, UV blocking, oxygen scavenging, water vapor permeability effects, and low environmental impact. In recent years, the migration of metal NPs and metal oxides in food contact packaging and their toxicological potential have raised concerns about the safety of the nanomaterials. In this review, we provide a comprehensive overview of the main biobased and biodegradable polymer nanocomposites, inorganic NPs, natural antioxidants, and their potential use in active food packaging. The intrinsic properties of NPs and natural antioxidant actives in packaging materials are evaluated to extend shelf-life, safety, and food quality. Toxicological and safety aspects of inorganic NPs are highlighted to understand the current controversy on applying some nanomaterials in food packaging. The synergism of inorganic NPs and plant-derived natural antioxidant actives (e.g., vitamins, polyphenols, and carotenoids) and essential oils (EOs) potentiated the antibacterial and antioxidant properties of biodegradable nanocomposite films. Biodegradable packaging films based on green NPs-this is biosynthesized from plant extracts-showed suitable mechanical and barrier properties and had a lower environmental impact and offered efficient food protection. Furthermore, AgNPs and TiO₂ NPs released metal ions from packaging into contents insufficiently to cause harm to human cells, which could be helpful to understanding critical gaps and provide progress in the packaging field.

A review on nanomaterials and nanohybrids based bio-nanocomposites for food packaging

With an increasing demand for a novel, eco-friendly, high-performance packaging material "bio-nanocomposites" has attracted great attention in recent years. The review article aims at to evaluating recent innovation in bio-nanocomposites for food packaging applications. The current trends and research over the last three years of the various bio-nanocomposites including inorganic, organic nanomaterials, and nanohybrids, which are suitable as food packaging materials due to their advanced properties such as high mechanical, thermal, barrier, antimicrobial, and antioxidant are described in detail. In addition, the legislation, migration studies, and SWOT analysis on bio-nanocomposite film have been discussed. It has been observed that the multifunctional properties of the bio-nanocomposite materials, has the potential to improve the quality and safety of the food together with no /or fewer negative impact on the environment. However, more studies need to be performed on bio-nanocomposite materials to determine the migration levels and formulate relevant legislation.

High-Throughput Fabrication of Antibacterial Starch/PBAT/AgNPs@SiO2 Films for Food Packaging

In this current work, antimicrobial films based on starch, poly(butylene adipate-co-terephthalate) (PBAT), and a commercially available AgNPs@SiO₂ antibacterial composite particle product were produced by using a melt blending and blowing technique. The effects of AgNPs@SiO₂ at various loadings (0, 1, 2, 3, and 4 wt%) on the physicochemical properties and antibacterial activities of starch/PBAT composite films were investigated. AgNPs@SiO₂ particles were more compatible with starch than PBAT, resulting in preferential distribution of AgNPs@SiO₂ in the starch phase. Infusion of starch/PBAT composite films with AgNPs@SiO₂ marginally improved mechanical and water vapor barrier properties, while surface hydrophobicity increased as compared with films without AgNPs@SiO₂. The composite films displayed superior antibacterial activities against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The sample loaded with 1 wt% AgNPs@SiO₂ (SPA-1) showed nearly 90% inhibition efficiency on the tested microorganisms. Furthermore, a preliminary study on peach and nectarine at 53% RH and 24 °C revealed that SPA-1 film inhibited microbial spoilage and extended the product shelf life as compared with SPA-0 and commercial LDPE packaging materials. The high-throughput production method and strong antibacterial activities of the starch/PBAT/AgNPs@SiO₂ composite films make them promising as antimicrobial packaging materials for commercial application.

Barrier performance and biodegradability of antibacterial poly(butylene adipate-co-terephthalate) nanocomposites reinforced with a new MWCNT-ZnO nanomaterial

A new nanomaterial or nano-filler in the form of multiwalled carbon nanotube-zinc oxide (MWCNT-ZnO) was synthesized for the purpose of modifying poly(butylene adipate-co-terephthalate) (PBAT) and its derivative (modified PBAT or MPBAT) through a melt-blending method (MPBAT was obtained by introducing maleic anhydride groups into PBAT). The effect of the new nano-filler on the properties of resultant nanocomposites was determined from the characterization of mechanical properties, morphology, crystallinity, thermal stability, barrier properties, hydrophilicity, conductivity, antibacterial property, and biodegradability. The results showed that MPBAT nanocomposites had stronger mechanical properties, better barrier properties, and higher electrical conductivity than PBAT nanocomposites. Scanning electron microscopy illustrated that MWCNT-ZnO had better compatibility with MPBAT than with PBAT. At 0.2% MWCNT-ZnO, the MPBAT/MWCNT-ZnO nanocomposite film exhibited the greatest mechanical properties (17.74% increase in tensile strength, 22.17% in yield strength, and 14.29% in elongation at break). When the MWCNT-ZnO content was 0.4%, the nanocomposite film demonstrated the best water vapor barrier ability (an increase of 30.4%). The MPBAT/MWCNT-ZnO film with 0.6% MWCNT-ZnO turned out to have the best oxygen barrier performance (an increase of 130% relative to pure PBAT). It was shown from the results of antibacterial evaluation that the new nanomaterial could impart PBAT and MPBAT with antibacterial activity. The biodegradability tests indicated that an MWCNT-ZnO content of 0.2% could slightly reduce the biodegradability, and when the content was higher than 0.2%, the weight loss rate would increase.

Biodegradable Poly(butylene adipate-co-terephthalate) Antibacterial Nanocomposites Reinforced with MgO Nanoparticles

Antibacterial packaging materials can reduce the microbial contamination of food surfaces. In this study, magnesium oxide (MgO) nanoparticles were synthesized and then coated with cetrimonium bromide (CTAB). CTAB-modified MgO (MgO@CTAB) was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis. Then, different loadings of MgO@CTAB were mixed with poly(butylene adipate-co-terephthalate) (PBAT) by melt compounding. The results showed that the addition of MgO@CTAB deteriorated the thermal stability of PBAT due to MgO serving as a catalyst to promote the thermal degradation of PBAT. In addition, MgO@CTAB could serve as a nucleating agent to improve the crystallinity of PBAT. With the optimal 3 wt% of MgO@CTAB, the tensile strength of PBAT/MgO@CTAB increased from 26.66 to 29.90 MPa, with a slight enhancement in elongation at break. SEM observations and dynamical rheological measurements revealed that aggregation occurred when the content of MgO@CTAB exceeded 5 wt%. The presence of MgO@CTAB endowed PBAT with antibacterial properties. The bacterial inhibition zone increased with the increasing content of MgO@CTAB. In addition, MgO@CTAB had a better antibacterial efficiency against Gram-positive bacterial S. aureus than Gram-negative bacterial E. coli.

Morphological, Structural, Thermal, Permeability, and Antimicrobial Activity of PBS and PBS/TPS Films Incorporated with Biomaster-Silver for Food Packaging Application

The development of antimicrobial film for food packaging application had become the focus for researchers and scientists. This research aims to study the characteristics and antimicrobial activity of novel biofilms made of poly (butylene succinate) (PBS) and tapioca starch (TPS) added with 1.5% or 3% of Biomaster-silver (BM) particle. In morphological examination, the incorporation of 3% BM particle was considerably good in forming well-structured PBS film. Meanwhile, the functional groups analysis revealed the 3% BM particle was effectively interacted with PBS molecular chains. The flame retard behavior of BM metal particle also helped in enhancing the thermal stability for pure PBS and PBS/TPS films. The nucleating effect of BM particles had improved the films crystallinity. Small pore size features with high barrier property for gas permeability was obtained for BM filled PBS/TPS films. From antimicrobial analysis, the BM particles possessed antimicrobial activity against three bacteria Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium in which PBS/TPS 3% BM film exhibited strong antimicrobial activity against all tested bacteria, however, PBS/TPS 1.5% BM film exhibited strong antimicrobial activity against E. coli only. Hence, the incorporation of BM into PBS/TPS film could be a sustainable way for developing packaging films to preserve food products.

Curcumin Incorporated Poly(Butylene Adipate-co-Terephthalate) Film with Improved Water Vapor Barrier and Antioxidant Properties

Curcumin incorporated poly(butylene adipate-co-terephthalate) (PBAT) based film was fabricated. Curcumin has uniformly distributed in the PBAT matrix to form a bright yellow PBAT/curcumin film. The PBAT/curcumin film has slightly reduced tensile strength and flexibility than the neat PBAT film, while the thermal stability of the film has not changed significantly. The blending of curcumin significantly decreased the water vapor permeability of the PBAT film. Additionally, the PBAT/curcumin film showed potent antioxidant activity with some antimicrobial activity. The PBAT/curcumin films with improved water vapor barrier and additional functions can be used for active packaging applications.