Bioactive and functional biodegradable packaging films reinforced with nanoparticles

Preparation of edible films from pectin/carboxymethyl chitosan incorporating polyphenol-rich roselle leaf extracts for food packaging applications

This study aimed to design an innovative antioxidant and antibacterial film for functional and health-promoting food packaging materials using food-grade polysaccharides incorporated with polyphenol-rich roselle leaf extracts (RLE). The films were fabricated using the casting method of pectin (P), carboxymethyl chitosan (CMC), and RLE. Six sets of films; 3 control films such as pectin (P-0), carboxymethyl chitosan (CMC-0), pectin plus carboxymethyl chitosan (PCMC-0), and 3 treated films such as pectin (PR-3), carboxymethyl chitosan (CMCR-3), (PCMCR-3) with 3 % RLE were prepared respectively to study the effects of RLE on the properties and function of prepared films. The water vapor permeability of the films ranged from 4.16 ± 0.04 g mm/h·m2·kPa to 6.93 ± 0.07 g mm/h·m2·kPa, with RLE-incorporated samples exhibiting lower permeability than the control sample. The maximum tensile strength (53.00 ± 1.07 MPa) and elongation of break (85.83 ± 2.81 %) were observed at PCMCR-3 containing 3 % RLE. The highest water contact angle (109.4 ± 0.16) was also noted in the PCMCR-3 film. The incorporation of RLE decreased the roughness of the film microstructure. The addition of RLE film CMC-R and PCMCR-3 notably enhanced the antibacterial and antioxidant properties of the edible film. Overall, the PCMCR-3 films extended the shelf life of fresh fish preserved at 4 ± 1 °C, offering promising innovative food preservation packaging materials for preserving perishable food products.

Konjac glucomannan/zein active film loaded with tea polyphenol-ferric nanoparticles for strawberry preservation

With increasing global environmental awareness and concerns about food safety, biodegradable active packaging has garnered widespread attention. In this study, the stability and bioactivity of tea polyphenol (TP) were enhanced through the preparation of TP-ferric nanoparticles (TP-Fe NPs) using metal-polyphenol ion coordination. Moreover, the introduction of Fe ions can further enhance the antibacterial effects of TP-Fe NPs. Using the hydrogen bonding between konjac glucomannan (KGM) and zein to enhance the hydrophobicity and mechanical properties of the film. By employing KGM and zein as the matrix, we incorporated TP-Fe NPs as active fillers to create multifunctional active packaging films. This study aimed to meet the needs of food safety and sustainable development goals. The resulting film exhibited excellent water resistance (water contact angle: 117.73°), mechanical strength (tensile strength: 21.82 MPa, elongation at break: 94.30 %), ultraviolet-shielding ability (>99 %), biodegradability (5 days in soil), and antioxidant (>85 %) and antibacterial (>99 %) properties. Moreover, the film significantly reduced strawberry decay and extended its shelf life by 10 days. These findings provide new insights into the application of nanomaterials in active packaging, highlighting their potential and advantages in food preservation.

Enhancing mechanical and blocking properties of gelatin films using zein-quercetin nanoparticle and applications for strawberry preservation

New gelatin films incorporated with zein-quercetin nanoparticles (GA/ZQNPs) were developed. The GA/ZQNP films had improved tensile strength, water vapor and oxygen barrier capabilities, hydrophobicity, UV blocking feature, antioxidant activities and antimicrobial properties, which varied with various contents of ZQNPs. Notably, the GA/ZQNP0.1-10 films exhibited enhanced tensile stress value around 3.2 MPa and strain of 142 %, a 78.4 % decrease in water vapor permeability, a 76.9 % decrease in oxygen permeability, the highest water contact angle at 112.0 ± 0.6°, an improved DPPH∙ scavenging rate of 64.9 ± 0.7 %, excellent UV blocking properties and antimicrobial properties. The GA/ZQNP films were further applied for strawberries packaging to assess their preservation capabilities under ambient conditions. The results showed that GA/ZQNP0.1-10 nanocomposite films efficiently maintained the best nutrient quality and acceptable appearance of strawberries compared with untreated strawberries, prolonging the shelflife of strawberries to approximately 8 days. These findings suggested promising applications for these new functional films in fruit packaging.

Valorization of raw papaya (Carica papaya) and citrus peels for development of antimicrobial and biodegradable edible film

Most of the food packaging materials used in the market are petroleum-based plastics; such materials are neither biodegradable nor environmentally friendly and require years to decompose. To overcome these problems, biodegradable and edible materials are encouraged to be used because such materials degrade quickly due to the actions of bacteria, fungi, and other environmental effects. The present study examined that starch can be effectively used as raw material to develop biodegradable, edible films. In this regard, Raw papaya and Citrus Peel were chosen to make biodegradable plastic film blended with corn starch. Raw papaya powder was combined with citrus peel powder for the development of film in treatments of T1, T2, T3, T4 and T5. RPP and CPP blend with Corn starch (CS) to maximize the film-forming properties and characteristics. The films were subjected to various parameter analysis like thickness, optical properties and barrier properties. As per the results, T3 was an optimized film, as it had minimum thickness (0.26 ± 0.01), high tensile strength (5.79 ± 0.12), elongation at break of 11.92 ± 0.03, High transparency (1.42 ± 0.06), and high degradation temperature. From the results, it is inferred that the prepared films are ideally suitable for food packaging and their production on a larger scale can considerably cut down the plastic wastage.

Sodium alginate-based indicator film with enhanced physicochemical properties induced by cellulose nanocrystals and monitor the freshness of chilled meat

Intelligent indicator films with colorimetric pH indicator properties were developed, incorporating black soybean seed coat anthocyanin (BA), cellulose nanocrystals (CNC), and sodium alginate (SA) to monitor meat freshness. The effect of different CNC additions on the microstructure, water barrier properties of the films, and BA release kinetics were comprehensively investigated. The results showed that with the increasement of CNC addition, the mechanical properties of SA/BA/CNC films were improved, the water contact angle significantly increased from 51.6° to 69°. Moreover, water solubility, vapor adsorption, and permeability significantly decreased, indicating enhanced water barrier properties. The release kinetic results showed that BA was released rapidly within 72 h and slowly thereafter, and its release process was described by Fick's model. Films with 7 % and 10 % CNC had lower BA diffusion coefficients. Their diffusions were formulated as linear regression equations (y = nx + a), where R2 was >0.80 and n was <0.50. Structural characterization showed that CNC immobilized BA mainly through hydrogen bonding, forming compact network microstructures with SA and BA. Meat freshness monitoring results showed that the film containing 7 % CNC showed visible color changes with increasing total volatile basic nitrogen and pH, along with low BA release, high water barrier and mechanical properties. Therefore, CNC has great potential for improving the physicochemical properties of indicator films, and the intelligent colorimetric indicator film could be applied to various food product.

Syzgium cumini seed/poly vinyl alcohol based water resistant biodegradable nano-cellulose composite reinforced with zinc oxide and silver oxide nanoparticles for improved mechanical properties

The current work explored a comparative study of biodegradable jamun seed/polyvinyl alcohol (JS) nanocomposites reinforced with varying concentrations of ZnO and Ag2O nano-fillers. The effect of spherical shaped ZnO and Ag2O nanoparticles (NPs) on the on structure, morphology, swelling and solubility, crystallinity and mechanical properties together with biodegradation performance of the composite films was fully studied. SEM results showed uniform distribution of ZnO and Ag2O nanofillers into the JS matrix and dense or compact nanocomposite films were formed. JS-ZnO and JS-Ag2O nanocomposites with 0.5 wt% ZnO and Ag2O content showed maximum crystallinity i.e. 11.3 and 9.58 %, respectively, as determined by XRD. When compared to the virgin JS film (8.41 MPa), the resultant JS-ZnO-0.5 and JS-Ag2O-0.5 nanocomposites showed significantly enhanced tensile strength (35.7 MPa, 29.2 MPa), elongation at break (15.42 %, 14.62 %) and Young's modulus (141 MPa, 126 MPa), respectively. Also, reduced swelling (120.4 % and 116.1 %) and solubility ratio (17.45 % and 18.42 %) was observed for JS-ZnO-0.5 and JS-Ag2O-0.5 nanocomposites, respectively. Biodegradation results showed that maximum degradation (88 %) was achieved for the JS film within 180 days of soil burial whereas JS-ZnO-0.1 and JS-Ag2O-0.1 nanocomposites showed 78 % and 72 % degradation within 180 days, respectively.

Bibliometric study and potential applications in the development of starch films with nanocellulose: A perspective from 2019 to 2023

This study aimed to perform a bibliometric analysis of starch films with nanocellulose, using the Scopus database and VOSviewer and Bibliometrix software. A total of 258 documents were identified between 2019 and 2023, reflecting a growing interest in research, particularly in journals such as the International Journal of Biological Macromolecules, Polymers, and Carbohydrate Polymers. The most common terms were "starch" (349 occurrences), "cellulose" (207), and "tensile strength" (175). China (58 articles), Brazil (38), and India (33) led scientific production, with authors like Ilyas (13 articles) and Sapuan (10) at the forefront. Approximately 41.7 % of the studies used corn starch. The analysis revealed that 66 % of the studies investigated films with cellulose nanofibrils (CNF), 32 % with cellulose nanocrystals (CNC), and 2 % with bacterial nanocellulose (CB). The majority of studies (94.1 %) used the casting method for film production. Additionally, 35.44 % focused on reinforcing films with nanocellulose, while 7 % developed blends with other biopolymers. About 59.44 % examined the performance of starch films for food packaging, 11.25 % explored practical applications in various foods. Furthermore, 7.94 % incorporated active agents to improve antioxidant and antimicrobial properties, 1.30 % investigated active packaging. Moreover, 2.36 % explored the use of films in materials engineering, and 2.36 % explored biomedical potential. Only 0.40 % evaluated the impact of films on wastewater treatment. The analysis highlights the potential of starch films with nanocellulose, demonstrating their diverse applications and the growing interest in the field.

Review of Bio-Based Biodegradable Polymers: Smart Solutions for Sustainable Food Packaging

Conventional passive packaging plays a crucial role in food manufacturing by protecting foods from various external influences. Most packaging materials are polymer-based plastics derived from fossil carbon sources, which are favored for their versatility, aesthetic appeal, and cost-effectiveness. However, the extensive use of these materials poses significant environmental challenges due to their fossil-based origins and persistence in the environment. Global plastic consumption for packaging is expected to nearly triple by 2060, exacerbating the ecological crisis. Moreover, globalization has increased access to a diverse range of foods from around the world, heightening the importance of packaging in providing healthier and safer foods with extended shelf life. In response to these challenges, there is a growing shift to eco-friendly active packaging that not only protects but also preserves the authentic qualities of food, surpassing the roles of conventional passive packaging. This article provides a comprehensive review on the viability, benefits, and challenges of implementing bio-based biodegradable polymers in active food packaging, with the dual goals of environmental sustainability and extending food shelf life.

Opportunities and Challenges in the Application of Bioplastics: Perspectives from Formulation, Processing, and Performance

Tremendously negative effects have been generated in recent decades by the continuously increasing production of conventional plastics and the inadequate management of their waste products. This demands the production of materials within a circular economy, easy to recycle and to biodegrade, minimizing the environmental impact and increasing cost competitiveness. Bioplastics represent a sustainable alternative in this scenario. However, the replacement of plastics must be addressed considering several aspects along their lifecycle, from bioplastic processing to the final application of the product. In this review, the effects of using different additives, biomass sources, and processing techniques on the mechanical and thermal behavior, as well as on the biodegradability, of bioplastics is discussed. The importance of using bioplasticizers is highlighted, besides studying the role of surfactants, compatibilizers, cross-linkers, coupling agents, and chain extenders. Cellulose, lignin, starch, chitosan, and composites are analyzed as part of the non-synthetic bioplastics considered. Throughout the study, the emphasis is on the use of well-established manufacturing processes, such as extrusion, injection, compression, or blow molding, since these are the ones that satisfy the quality, productivity, and cost requirements for large-scale industrial production. Particular attention is also given to fused deposition modeling, since this additive manufacturing technique is nowadays not only used for making prototypes, but it is being integrated into the development of parts for a wide variety of biomedical and industrial applications. Finally, recyclability and the commercial requirements for bioplastics are discussed, and some future perspectives and challenges for the development of bio-based plastics are discussed, with the conclusion that technological innovations, economic incentives, and policy changes could be coupled with individually driven solutions to mitigate the negative environmental impacts associated with conventional plastics.

Development of multifunctional chitosan-based composite film loaded with tea polyphenol nanoparticles for strawberry preservation

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation.

Application of Natural Functional Additives for Improving Bioactivity and Structure of Biopolymer-Based Films for Food Packaging: A Review

The global trend towards conscious consumption plays an important role in consumer preferences regarding both the composition and quality of food and packaging materials, including sustainable ones. The development of biodegradable active packaging materials could reduce both the negative impact on the environment due to a decrease in the use of oil-based plastics and the amount of synthetic preservatives. This review discusses relevant functional additives for improving the bioactivity of biopolymer-based films. Addition of plant, microbial, animal and organic nanoparticles into bio-based films is discussed. Changes in mechanical, transparency, water and oxygen barrier properties are reviewed. Since microbial and oxidative deterioration are the main causes of food spoilage, antimicrobial and antioxidant properties of natural additives are discussed, including perspective ones for the development of biodegradable active packaging.

Chitosan-Based Films Blended with Tannic Acid and Moringa Oleifera for Application in Food Packaging: The Preservation of Strawberries (Fragaria ananassa)

Biobased plastics provide a sustainable alternative to conventional food packaging materials, thereby reducing the environmental impact. The present study investigated the effectiveness of chitosan with varying levels of Moringa oleifera seed powder (MOSP) and tannic acid (TA). Chitosan (CS) biocomposite films with tannic acid acted as a cross-linker, and Moringa oleifera seed powder served as reinforcement. To enhance food packaging and film performance, Moringa oleifera seed powder was introduced at various loadings of 1.0, 3.0, 5.0, and 10.0 wt.%. Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analyses were performed to study the structure and morphology of the CS/TA/MOSP films. The scanning electron microscopy results confirmed that chitosan/TA with 10.0 wt.% of MOSP produced a lightly miscible droplet/matrix structure. Furthermore, mechanical properties, swelling, water solubility, optical barrier, and water contact angle properties of the film were also calculated. With increasing Moringa oleifera seed powder contents, the biocomposite films' antimicrobial and antifungal activity increased at the 10.0 wt.% MOSP level; all of the observed bacteria [Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Aspergillus niger (A. niger), and Candida albicans (C. albicans)] had a notably increased percentage of growth. The film, with 10.0 wt.% MOSP content, effectively preserves strawberries' freshness, making it an ideal food packaging material.

Biomaterials and bioelectronics for self-powered neurostimulation

Self-powered neurostimulation via biomaterials and bioelectronics innovation has emerged as a compelling approach to explore, repair, and modulate neural systems. This review examines the application of self-powered bioelectronics for electrical stimulation of both the central and peripheral nervous systems, as well as isolated neurons. Contemporary research has adeptly harnessed biomechanical and biochemical energy from the human body, through various mechanisms such as triboelectricity, piezoelectricity, magnetoelasticity, and biofuel cells, to power these advanced bioelectronics. Notably, these self-powered bioelectronics hold substantial potential for delivering neural stimulations that are customized for the treatment of neurological diseases, facilitation of neural regeneration, and the development of neuroprosthetics. Looking ahead, we expect that the ongoing advancements in biomaterials and bioelectronics will drive the field of self-powered neurostimulation toward the realization of more advanced, closed-loop therapeutic solutions, paving the way for personalized and adaptable neurostimulators in the coming decades.

Development and characterization of an active starch-based film as a chlorogenic acid delivery system

Given its health benefits for the human body, chlorogenic acid (CA) offers promising applications in the food industry. However, the instability and low bioavailability of CA remain to be solved. In this paper, a starch-based film prepared by the homogenization and solution-casting method was used as an effective carrier to alleviate these problems. Homogenization (10-50 MPa) reduced the starch paste viscosity and its particle sizes from 21.64 to 7.68 μm, which promoted the starch recrystallization and induced chemical cross-links between starch-CA, as confirmed by the FTIR result with an appearance of a new CO peak at about 1716 cm-1. Accordingly, the rapidly digestible starch content of the film was reduced to 27.83 % and the CA encapsulation efficiency was increased to 99.08 % (from 65.88 %). As a result, the film system extended CA's release time beyond 4 h and significantly increased the heat-treated CA's antioxidant activity. Besides, the tensile strength and elastic modulus of the film were also improved to 6.29 MPa (from 1.63 MPa) and 160.98 MPa (from 12.02 MPa), respectively, by homogenization. In conclusion, the developed active starch-based film could be used as an edible film for the production of functional food or active food packaging.

Valorizing pomegranate wastes by producing functional silver nanoparticles with antioxidant, anticancer, antiviral, and antimicrobial activities and its potential in food preservation

The food sector generates massive amounts of waste, which are rich in active compounds, especially polyphenols; therefore, valorizing these wastes is a global trend. In this study, we produce silver nanoparticles from pomegranate wastes, characterized by enhanced antioxidant, anticancer, antiviral, and antimicrobial properties and investigated their potential to maintain the fruit quality for sixty days in market. The pomegranate waste-mediated silver nanoparticles (PPAgNPs) were spherical shape (measured by TEM), 20 nm (Zeta sizer), negatively charged -25.98 mV (Zeta potential), and surrounded by active groups (FTIR). The PPAgNPs scavenged 94 % of DPPH radicals and inhibited the growth of pathogens, i.e., Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, Salmonella typhi and Candida with inhibition zones diameters (16-45 mm). They impeded the development of breast and colon cancer cell lines by 80 and 78 %, increased the activity of apoptosis marker caspase 3, and inhibited 82 % of COVID-19. The PPAgNPs were added to the rat diet at 80, 160, and 320 µg/kg levels. PPAgNPs administered at a concentration of 160 µg/kg in the rat diet resulted in the best growth performance, normal liver and kidney parameters (p = 0.029-0.038), lowered lipid profile, malondialdhyde (MDA), and raised glutathion reduced (GSH), total protein (TP). Also, the reduced gene expression of Interleukin 6 (IL-6) and Tumor necrosis factor alpha (TNF-α) in albino rats' serum indicates the anti-inflammatory effect of PPAgNPs. PPAgNPs developed a functional coating to preserve mandarin fruit for 60 days by dipping technique. The active coat containing PPAgNPs can effectively preserve the fruit for 60 days.

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.

Development and Characterization of Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopapers Containing Cerium Oxide Nanoparticles for Active Food Packaging Applications

Food quality is mainly affected by oxygen through oxidative reactions and the proliferation of microorganisms, generating changes in its taste, odor, and color. The work presented here describes the generation and further characterization of films with active oxygen scavenging properties made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) loaded with cerium oxide nanoparticles (CeO₂NPs) obtained by electrospinning coupled to a subsequent annealing process, which could be used as coating or interlayer in a multilayer concept for food packaging applications. The aim of this work is to explore the capacities of these novel biopolymeric composites in terms of O₂ scavenging capacity, as well as antioxidant, antimicrobial, barrier, thermal, and mechanical properties. To obtain such biopapers, different ratios of CeO₂NPs were incorporated into a PHBV solution with hexadecyltrimethylammonium bromide (CTAB) as a surfactant. The produced films were analyzed in terms of antioxidant, thermal, antioxidant, antimicrobial, optical, morphological and barrier properties, and oxygen scavenging activity. According to the results, the nanofiller showed some reduction of the thermal stability of the biopolyester but exhibited antimicrobial and antioxidant properties. In terms of passive barrier properties, the CeO₂NPs decreased the permeability to water vapor but increased the limonene and oxygen permeability of the biopolymer matrix slightly. Nevertheless, the oxygen scavenging activity of the nanocomposites showed significant results and improved further by incorporating the surfactant CTAB. The PHBV nanocomposite biopapers developed in this study appear as very interesting constituents for the potential design of new active organic recyclable packaging materials.

Effects of Hydroxypropyl Methylcellulose on Physicochemical Properties and Microstructure of κ-Carrageenan Film

We investigated the effects of different proportions of hydroxypropyl methylcellulose (HPMC) on the properties of κ-carrageenan film. Biodegradable κ-carrageenan/HPMC films (κCHM film) were prepared by the solution casting method and their physicochemical properties were evaluated. The results show that the addition of HPMC enhanced oxygen barrier capacity, mechanical properties (tensile strength and elongation at break) and thermal stability. Notably, when the addition of HPMC increased to 6% of κ-carrageenan (w:w), the κCHM-6 film not only effectively improved water resistance, including lower water solubility, water vapor permeability and higher water contact angle, but also made the structure of the κCHM-6 film more compact. Moreover, rheological measurement and atomic force microscopy characterization showed that κ-carrageenan had suitable compatibility with HPMC. Attenuated total reflection–Fourier transform infrared spectroscopy analysis further confirmed the enhancement of hydrogen bond interactions. This finding could contribute to promoting the potential application of κCHM film in food packaging.

Whey protein isolate/jujube polysaccharide-based edible nanocomposite films reinforced with starch nanocrystals for the shelf-life extension of banana: Optimization and characterization

The formulation of new bionanocomposite (BNC) films using whey protein isolates (WPI, 3.3-11.7 %)-jujube polysaccharide (JPS, 1.59-18.41 %)/starch nanocrystals (SNCs, 0.32-3.68 %) blends was optimized. The ultrasound-assisted acid hydrolysis produced ~63.1 nm SNCs from native starch with -24.3 mV ζ-potential. The extracted JPS purification led to a single symmetrical peak for galactoarabinan-rich fraction (1.35 × 10⁵ Da). The optimal levels of barrier (oxygen (11.85 cm³ m^-2 d^-1 atm^-1) and water vapor (3.22 × 10^-10 g m^-1 s^-1 Pa^-1) permeability rate), optical (opacity index (2.7 AU μm^-1), total color difference (18.69), and whiteness index (77.40)), and thermal (glass transition temperature (-8.29 °C) and melting point (110.38 °C)) properties were obtained at 5.0 % WPI, 15.0 % JPS, and 3.0 % SNCs. The film-forming solution of optimal BNCs had a significant antibacterial effect against Staphylococcus aureus and Escherichia coli. The improved crystallinity of BNCs at an optimal SNC level was confirmed by the XRD. The AFM and SEM images confirmed a continuous and uniform network for the optimal BNCs without any pores or cracks accompanied by low surface roughness. The FTIR spectroscopy proved covalent interaction and hydrogen bonding among chemical functional groups of WPI and JPS reinforced with SNCs. The optimal BNC could preserve banana fruits with favorable physicochemical and microbial quality during storage.

Source of Nanocellulose and Its Application in Nanocomposite Packaging Material: A Review

Food packaging nowadays is not only essential to preserve food from being contaminated and damaged, but also to comply with science develop and technology advances. New functional packaging materials with degradable features will become a hot spot in the future. By far, plastic is the most common packaging material, but plastic waste has caused immeasurable damage to the environment. Cellulose known as a kind of material with large output, wide range sources, and biodegradable features has gotten more and more attention. Cellulose-based materials possess better degradability compared with traditional packaging materials. With such advantages above, cellulose was gradually introduced into packaging field. It is vital to make packaging materials achieve protection, storage, transportation, market, and other functions in the circulation process. In addition, it satisfied the practical value such as convenient sale and environmental protection, reduced cost and maximized sales profit. This review introduces the cellulose resource and its application in composite packaging materials, antibacterial active packaging materials, and intelligent packaging materials. Subsequently, sustainable packaging and its improvement for packaging applications were introduced. Finally, the future challenges and possible solution were provided for future development of cellulose-based composite packaging materials.

Recent advances in carrageenan-based films for food packaging applications

In order to solve the increasingly serious environmental problems caused by plastic-based packaging, carrageenan-based films are drawing much attentions in food packaging applications, due to low cost, biodegradability, compatibility, and film-forming property. The purpose of this article is to present a comprehensive review of recent developments in carrageenan-based films, including fabrication strategies, physical and chemical properties and novel food packaging applications. Carrageenan can be extracted from red algae mainly by hydrolysis, ultrasonic-assisted and microwave-assisted extraction, and the combination of multiple extraction methods will be future trends in carrageenan extraction methods. Carrageenan can form homogeneous film-forming solutions and fabricate films mainly by direct coating, solvent casting and electrospinning, and mechanism of film formation was discussed in detail. Due to the inherent limitations of the pure carrageenan film, physical and chemical properties of carrageenan films were enhanced by incorporation with other compounds. Therefore, carrageenan-based films can be widely used for extending the shelf life of food and monitoring the food freshness by inhibiting microbial growth, reducing moisture loss and the respiration, etc. This article will provide useful guidelines for further research on carrageenan-based films.

Alternative Controlling Agent of Theobroma grandiflorum Pests: Nanoscale Surface and Fractal Analysis of Gelatin/PCL Loaded Particles Containing Lippia origanoides Essential Oil

A new systematic structural study was performed using the Atomic Force Microscopy (AFM) reporting statistical parameters of polymeric particles based on gelatin and poly-ε-caprolactone (PCL) containing essential oil from Lippia origanoides. The developed biocides are efficient alternative controlling agents of Conotrachelus humeropictus and Moniliophtora perniciosa, the main pests of Theobroma grandiflorum. Our results showed that the particles morphology can be successfully controlled by advanced stereometric parameters, pointing to an appropriate concentration of encapsulated essential oil according to the particle surface characteristics. For this reason, the absolute concentration of 1000 µg·mL^-1 (P₁₀₀₀ system) was encapsulated, resulting in the most suitable surface microtexture, allowing a faster and more efficient essential oil release. Loaded particles presented zeta potential around (-54.3 ± 2.3) mV at pH = 8, and particle size distribution ranging from 113 to 442 nm. The hydrodynamic diameter of 90% of the particle population was found to be up to (405 ± 31) nm in the P₁₀₀₀ system. The essential oil release was evaluated up to 80 h, with maximum release concentrations of 63% and 95% for P₅₀₀ and P₁₀₀₀, respectively. The best fit for the release profiles was obtained using the Korsmeyer-Peppas mathematical model. Loaded particles resulted in 100% mortality of C. humeropictus up to 48 h. The antifungal tests against M. perniciosa resulted in a minimum inhibitory concentration of 250 µg·mL^-1, and the P₁₀₀₀ system produced growth inhibition up to 7 days. The developed system has potential as alternative controlling agent, due to its physical stability, particle surface microtexture, as well as pronounced bioactivity of the encapsulated essential oil.

Pulsatile Controlled Release and Stability Evaluation of Polymeric Particles Containing Piper nigrum Essential Oil and Preservatives

Considerable efforts have been spent on environmentally friendly particles for the encapsulation of essential oils. Polymeric particles were developed to encapsulate the essential oil from Piper nigrum based on gelatin and poly-ε-caprolactone (PCL) carriers. Gas Chromatography ((Flame Ionization Detection (GC/FID) and Mass Spectrometry (GC/MS)), Atomic Force Microscopy (AFM), Nanoparticle Tracking Analysis (NTA), Confocal Laser Scanning Microscopy (CLSM), Attenuated Total Reflectance-Fourier-transform Infrared Spectroscopy (ATR-FTIR), and Ultraviolet-Visible (UV-VIS) spectroscopy were used for the full colloidal system characterization. The essential oil was mainly composed of β-caryophyllene (~35%). The stability of the encapsulated systems was evaluated by Encapsulation Efficiency (EE%), electrical conductivity, turbidity, pH, and organoleptic properties (color and odor) after adding different preservatives. The mixture of phenoxyethanol/isotialzoni-3-one (PNE system) resulted in enhanced stability of approximately 120 and 210 days under constant handling and shelf-life tests, respectively. The developed polymeric system presented a similar controlled release in acidic, neutral, or basic pH, and the release curves suggested a pulsatile release mechanism due to a complexation of essential oil in the PCL matrix. Our results showed that the developed system has potential as an alternative stable product and as a controlling agent, due to the pronounced bioactivity of the encapsulated essential oil.

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.

Simple, One-Pot Method for Preparing Transparent Ethyl Cellulose Films with Good Mechanical Properties

In this research, ethyl cellulose films were prepared by a simple, easy, controlled one-pot method using either ethanol or ethyl lactate as solvents, the films being formed at 6 °C. Titanium dioxide nanoparticles were incorporated to improve the oxygen transmission and water vapour transmission rates of the obtained films. This method used no plasticizers, and flexible materials with good mechanical properties were obtained. The resulting solvent-free and transparent ethyl cellulose films exhibited good mechanical properties and unique free-shapable properties. The obtained materials had similar properties to those reported in the literature, where plasticizers were incorporated into ethyl cellulose films with an elastic modulus of 528 MPa. Contact angles showed the hydrophobic nature of all the prepared materials, with contact angles between 80 and 108°. Micrographs showed the smooth surfaces of the prepared samples and porous intersections with honeycomb-like structures. The oxygen and water vapor transmission rates were the lowest for the ethyl cellulose films prepared in ethyl lactate, these being 615 cm³·m⁻²·day⁻¹ and 7.8 gm⁻²·day⁻¹, respectively, showing that the films have promise for food packaging applications.

Crystallization of microbial polyhydroxyalkanoates: A review

Polyhydroxyalkanoates (PHAs), produced by the microbial fermentation, is a promising green polymer and has attracted much attention due to its excellent biocompatibility, complete biodegradability, and non-cytotoxicity. The physical properties of PHAs are closely related to their chemical and crystalline structure. Therefore, deep understanding and regulating the structure and crystallization of PHAs are the key factors to improve the performance of PHAs. This review first provides a brief overview of the development history, chemical structure, and basic properties of PHAs. Then, the crystal structure, crystal morphology, kinetics theories and crystallization behavior of nucleation-induced PHAs are systematically summarized to provide a theoretical foundation for improving PHAs crystallization rate and physical properties. In the end, the outlook on the crystallization and application prospects of PHAs is also addressed.

Preparation of antibacterial nanofibers by electrospinning polyvinyl alcohol containing a luteolin hydroxypropyl-β-cyclodextrin inclusion complex

Nanofibers have exhibited excellent water solubility, significant antibacterial effects and effective concentration in vitro release.