Polylactide films produced with bixin and acetyl tributyl citrate: Functional properties for active packaging

Packaging materials are decisive to preserve the quality and nutritional value of food. Polylactide (PLA) is a biodegradable polymer with adequate mechanical properties for packaging applications, but its moderate oxygen barrier properties and high UV light transmission hamper its performance as packaging for oxygen- and light-sensitive products. Bixin, a carotenoid with coloring and antioxidant character, was used to improve the light barrier of PLA films plasticized or not with acetyl tri-butyl citrate (ATBC). The films were subjected to thermal treatment mimicking polymer processing temperatures. Despite more than 74 wt% of bixin degraded during heat treatment, films were still blocking up to 95% of UVA and 90% of UVB transmission. Plasticizing PLA with ATBC accelerated up to six times the bixin release into a food simulant, which allowed to reach relevant concentrations for food preservation. In conclusion, bixin is a promising natural antioxidant and UV-shielding additive of biodegradable packaging.     

Recently emerging trends in polymer nanocomposites packaging materials

As a result of excellent nanoparticle dispersion tendencies, polymer based nanocomposites exhibit a significantly enhanced packaging characteristics. Moreover, the feasibility of inclusion of biologically-active additives has shown great potentials of rendering enhanced functional properties to the end product. Hence, polymer nanocomposites exhibiting bio-functional propensities have revealed a broad potential for application as packaging materials in the functional food packaging industry. This is due to accruable improvements in properties such as enhancements in strength and modulus, reduced gas permeability, and increment in resistance to water. Thus, the incumbent paper discusses state of the act recently emerging trends in the preparation and characterization of polymer nanocomposites as eco-benign and biodegradable packaging materials, inaddition to their future market prospects.Emerging novelties in polymer nanocomposites packaging films.     

Selected Applications of Chitosan Composites

Chitosan is one of the emerging materials for various applications. The most intensive studies have focused on its use as a biomaterial and for biomedical, cosmetic, and packaging systems. The research on biodegradable food packaging systems over conventional non-biodegradable packaging systems has gained much importance in the last decade. The deacetylation of chitin, a polysaccharide mainly obtained from crustaceans and shrimp shells, yields chitosan. The deacetylation process of chitin leads to the generation of primary amino groups. The functional activity of chitosan is generally owed to this amino group, which imparts inherent antioxidant and antimicrobial activity to the chitosan. Further, since chitosan is a naturally derived polymer, it is biodegradable and safe for human consumption. Food-focused researchers are exploiting the properties of chitosan to develop biodegradable food packaging systems. However, the properties of packaging systems using chitosan can be improved by adding different additives or blending chitosan with other polymers. In this review, we report on the different properties of chitosan that make it suitable for food packaging applications, various methods to develop chitosan-based packaging films, and finally, the applications of chitosan in developing multifunctional food packaging materials. Here we present a short overview of the chitosan-based nanocomposites, beginning with principal properties, selected preparation techniques, and finally, selected current research.     

Chia seeds to develop new biodegradable polymers for food packaging: Properties and biodegradability

Chia seeds are a promising raw material for the development of biodegradable and edible polymers due to their composition and properties. This study aimed to evaluate the effects of drying process of chia mucilage (oven and freeze-drying) and the incorporation of chia oil in films for food packaging. The films were formed by casting using chia mucilage and glycerol. The polymers developed were evaluated by physicochemical properties, microstructure, thermal properties, and biodegradation. The drying process of mucilage and oil incorporation in films affected mainly mechanical and color properties. Freeze-dried mucilage resulted in superior mechanical performance. Differences were caused by the effect of drying process in the molecular structure of chia mucilage and the incorporation of oil among the polymer chains. Chia mucilage films were completely soluble in water and biodegraded in a short time in soil. These films are promising biodegradable polymers for the development of eco-friendly food packaging and edible sachets for small pre-measured portions, preventing environment pollution and facilitating product consumption.     

Nanocellulose-Polymer Composites for Applications in Food Packaging: Current Status,Future Prospects and Challenges

Nanocellulose has potential applications across the several industrial sectors and addresses a lot of issues related to environmental concern. As biodegradable filler in composite manufacturing, coating, and self-standing thin films, it offers novel and promising properties. Very few available reviews report on nanocellulose-impregnated composite materials for food packaging. Nanocellulose reinforcement is found to be promising for mechanical and barrier properties of composite for biopolymer and synthetic polymer. In this paper, we provide a thorough review of recent advances of nanocellulose synthesis and its application as a filler material for production of nanocomposites to be used for food packaging.     

The use of sol–gel film as pre-treatment for tinplate used in the canning industry

Tinplate cans are extensively used in the food packaging industry. The regular practice includes a passivation process, usually based on chromate films. Although they have good performance, their contaminant and unhealthy character makes necessary the research of new alternatives.     

Palm oil deodorizer distillate as toughening agent in polylactide packaging films

Polylactide (PLA) is the most used biodegradable and biobased food packaging polymer for rigid containers and films. However, its low ductility is a hurdle for increasing its applications in flexible food packaging. A solution is the use of additives. Palm oil deodorizer distillate (PODC) is revealed to be an excellent additive promoting PLA ductility. PODC is a by‐product of vegetable oil refining, which is available in stable quality and in sufficient amounts. Amorphous PLA/PODC blends had an elongation at break of around 130% and that of semi‐crystalline blends was still around 55% compared to the initial 5% of neat PLA. At the same time the PLA rigidity and high glass transition temperatures were kept. PODC was also a very efficient processing aid, allowing for film blow extrusion. The blends were stable in properties during six months without exudation. They complied with legal norms of Food Contact Materials (EU 10/2011) and induced no sensorial alteration of packed food. Therefore PODC is a very interesting alternative to common plasticizers for the production of flexible PLA packaging films. © 2016 Society of Chemical Industry     

Design of Polymeric Films for Antioxidant Active Food Packaging

Antioxidant active food packaging can extend the shelf life of foods by retarding the rate of oxidation reactions of food components. Although significant advances in the design and development of polymeric packaging films loaded with antioxidants have been achieved over the last several decades, few of these films have successfully been translated from the laboratory to commercial applications. This article presents a snapshot of the latest advances in the design and applications of polymeric films for antioxidant active food packaging. It is hoped that this article will offer insights into the optimisation of the performance of polymeric films for food packaging purposes and will facilitate the translation of those polymeric films from the laboratory to commercial applications in the food industry.     

Biodegradable and functionally superior starch–polyester nanocomposites from reactive extrusion

Biodegradable starch‐polyester polymer composites are useful in many applications ranging from numerous packaging end‐uses to tissue engineering. However the amount of starch that can form composites with polyesters without significant property deterioration is typically less than 25% because of thermodynamic immiscibility between the two polymers. We have developed a reactive extrusion process in which high amounts of starch (approx. 40 wt%) can be blended with a biodegradable polyester (polycaprolactone, PCL) resulting in tough nanocomposite blends with elongational properties approaching that of 100% PCL. We hypothesize that starch was oxidized and then crosslinked with PCL in the presence of an oxidizing/crosslinking agent and modified montmorillonite (MMT) organoclay, thus compatibilizing the two polymers. Starch, PCL, plasticizer, MMT organoclay, oxidizing/crosslinking agent and catalysts were extruded in a co‐rotating twin‐screw extruder and injection molded at 120° C. Elongational properties of reactively extruded starch‐PCL nanocomposite blends approached that of 100% PCL at 3 and 6 wt% organoclay. Strength and modulus remained the same as starch‐PCL composites prepared from simple physical mixing without any crosslinking. X‐ray diffraction results showed mainly intercalated flocculated behavior of clay at 1,3,6, and 9wt% organoclay. Scanning electron microscopy (SEM) showed that there was improved starch‐PCL interfacial adhesion in reactively extruded blends with crosslinking than in starch‐PCL composites without crosslinking. Dynamic mechanical analysis showed changes in primary α‐transition temperatures for both the starch and PCL fractions, reflecting crosslinking changes in the nanocomposite blends at different organoclay contents. Also starch‐polytetramethylene adipate‐co‐terephthalate (PAT) blends prepared by the above reactive extrusion process showed the same trend of elongational properties approaching that of 100% PAT. The reactive extrusion concept can be extended to other starch‐PCL like polymer blends with polymers like polyvinyl alcohol on one side and polybutylene succinate, polyhydroxy butyrate‐valerate and polylactic acid on the other to create cheap, novel and compatible biodegradable polymer blends with increased toughness. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1072–1082, 2005     

Biodegradable Blown Film Composites from Bioplastic and Talc: Effect of Uniaxial Stretching on Mechanical and Barrier Properties

As public awareness about climate change grows, there is an increase in the research on bioplastic packaging films. This is the first-ever scientific report on uniaxially stretched biobased-polybutylene succinate-co-adipate (BioPBSA) and talc (15 and 25 wt%) based blown film composites at different stretch ratios (SR). The water vapor barrier properties of BioPBSA+25%Talc film at SR 4 shows an improvement of 40% compared to its unstretched counterpart, while an overall improvement of 48% is observed compared to the unstretched BioPBSA film. The successful dispersion of talc in the BioPBSA matrix, the orientation of talc filler during stretching, and the polymer chains orientation are responsible for such improvement. Additionally, XRD analysis shows that during uniaxial stretching, the crystallinity of the films increases by up to 26% as a result of strain-induced crystallization, with BioPBSA+25%Talc at SR 4 having the highest crystallinity (≈75%). Furthermore, the inclusion of 25% talc in BioPBSA considerably enhances the tensile modulus by 246% compared to its unstretched counterpart. Hence biodegradable films with balanced barrier and tensile properties may be promising alternatives to petroleum-based plastic materials used in flexible packaging applications.     

Recent Advances in Lipid Derived Bio-Based Materials for Food Packaging Applications

The utilization of lipids is presently in the spotlight of food industry as they are one of novel renewable and sustainable raw materials. Lipids derived materials are considered as a promising alternate to petro-based polymers as they are sustainable, biorenewable, biodegradable, and environmentally benign. These unique attributes draw the attention of scientific community for the use of lipids in food packaging applications with a potential to compete with fossil fuel derived polymers. This paper reviews recent advances in the use of lipids and their effect on the barrier, antimicrobial, antioxidant, and mechanical properties of films, coating and nanocomposites for food packaging applications. Modification of lipids and its chemical interactions with other biopolymers during processing for the synthesis of different materials are also discussed. Global patents and research trend in use of lipids for the preparation of biocomposites are also described. The role of lipids in the circular economy is highlighted and life cycle assessment of lipids derived products is outlined with examples. The review is concluded with synoptic view of existing and forthcoming potential use of lipids in various food packaging applications.     

Development of extrusion blown films of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) blends for flexible packaging

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polymer with significant potential for use in food packaging. However, its limited melt strength poses a challenge when employing film-blowing techniques to produce flexible packaging. To overcome this obstacle, we developed blends consisting of 70 wt% PHBV and 30 wt% poly(butylene-co-succinate-co-adipate) (PBSA). Organic peroxides such as dicumyl peroxide and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, were utilized as reactive compatibilizers to enhance the interfacial adhesion between the polymers. Additionally, acetyl tributyl citrate (ATBC) was employed as a plasticizer to improve processability and ductility. The inclusion of organic peroxides resulted in the formation of long-branched structures, as confirmed by the van-Gurp-Palmen plot. The melt flow index decreased from 30 to 9.8 g/10 min without ATBC and 15.5 g/10 min with ATBC. Successful production of blown PHBV/PBSA films was achieved on a pilot scale (bubble height 180 cm). These films exhibited heat-sealing capability and increased impact strength (7.7 kJ/m²). Moreover, the films maintained a maximum elongation at break of 4% during a 3-month storage experiment with frozen food. Food safety was assessed through overall migration experiments, and the non-plasticized films received approval. In conclusion, the compatibilized PHBV/PBSA blends demonstrate great potential as materials for manufacturing film-blown flexible packaging.     

Influence of biodegradable materials in the recycled polystyrene

Polystyrene (PS) is one of the commonly used polymer in food packaging, that is why it generates a large amount of residual PS: because of the need of reduce environmental damage that occurs, it is common to recycle this polymer. Recycling of PS may be affected by the introduction of biodegradable polymer in industrial food. For this reason we have studied the influence that generates small amounts of biodegradable polymer (PLA, PHB, and TPS) in the recycled PS properties. The recycled PS and biodegradable polymers blends were evaluated by measuring the Vicat softening temperature, melt flow index, Fourier transformed infrared spectroscopy, and mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41161.     

Biodegradable poly(vinyl alcohol)-based nanocomposite film reinforced with organophilic layered double hydroxides with potential packaging application

The continuously increasing plastic wastes and diminishing fossil resources have attracted global attention into research and development of biodegradable packaging materials. In the present study, organophilic layered double hydroxides (OLDH) intercalated with aliphatic long-chain molecules as reinforcing agents were incorporated into biodegradable poly(vinyl alcohol) (PVA) matrix by a solution casting method. FTIR, XRD and SEM were performed to analyze the structure of PVA/OLDH films. The OLDH nanosheets were well-dispersed in PVA matrix and formed strong interfacial interactions with the PVA chains, leading to remarkable improvements of optical property, mechanical performance, water vapor barrier property and thermal stability. At a loading of only 2% OLDH in PVA, we observed ~67% decrease in haze and ~66% increment in tensile strength in the composite film compared with pure PVA film. Furthermore, a 24.22% decrease in water vapor permeability (enhancement in water vapor barrier property) due to the addition of 0.5 wt% OLDH and enhanced thermal stability could be observed. These results revealed that the overall performance could be improved by introducing OLDH at very low loadings and that the PVA nanocomposite films have potential for future application in packaging films. Therefore, the use of high-performance PVA/OLDH nanocomposite films can evidently promote the application of biodegradable PVA materials in packaging industry.     

食品包装高分子材料技术进步与升级

分析了常用的包装高分子材料性能及优缺点,结合新型的加工方法和材料领域最新进展,分别讨论了双向拉伸聚乙烯、流延聚乙烯、聚丙烯薄膜、LISIM法双向拉伸聚酰胺薄膜和聚酯薄膜等包装材料;综述了多层复合包装材料的研究现状,对未来食品包装技术的发展趋势进行了展望,认为包装材料将向高阻隔、低重量和绿色化方向发展,而采用复合技术和先...     

Talc reinforcement of polylactide and biodegradable polyester blends via injection-molding and pilot-scale film extrusion

As a renewable and biodegradable polymer, polylactide (PLA) has taken a foothold in the packaging industry. However, the thermomechanical and barrier properties of PLA-based films need to be improved to facilitate a wider adoption. To address this challenge, we examined the effect of talc reinforcement in composites based on PLA and a biodegradable polyester. Masterbatches of the polymers and talc were produced by melt compounding and processed by either injection-molding or film extrusion in a pilot-scale unit operating at 60–80 m/min. The effect of talc was investigated in relation to the morphological, thermal, mechanical, and barrier properties of the composites. Based on SEM-imaging, talc was found to increase the miscibility of PLA and the polyester while acting as a nucleating agent that improved PLA crystallinity. While this effect did not track with an increased mechanical strength, the composites with 3–4 wt% talc displayed a significantly higher barrier to water vapor. Compared to the neat polymer films, a reduction of water vapor transmission rate, by ~34–37%, was observed at 23°C/50% RH. Meanwhile, the systems loaded with 1 wt% talc showed a reduction in oxygen transmission rates, by up to 34%. Our results highlight the challenges and prospects of commercial PLA-based blends filled with talc from films extruded in pilot-scale units.     

Mathematical analysis of transport properties of polymer films for food packaging. II. Generalized water vapor models

Deterioration or spoilage of dehydrated food products stored in flexible packaging materials depends on the partial pressure of water vapor in the environment of the stored food. Mathematical analysis of the diffusion of water vapor through semipermeable polymer films using Nernst-Planck equations is combined with non-liner water sorption isotherms on food to establish criteria and optimum conditions for storage stability of dehydrated food. Langmuir, Brunauer-Emmet-Teller (BET), Halsey, Oswin and Freundlich isotherms are used for various ranges of water activity. It is shown that a single parameter, the permeability-sorption constant, based on the physical properties of the polymer and the sorptive properties of the food, accounts for both diffusion and adostption and can be used to accurately determine maximum storage times and can be used to accurately determine maximum storage times and to optimize the selection of packaging films. The theory is extended to thermodynamically compatible solute-polymer systems, where the polymer film is swollen appreciably by the diffusing species.     

Green composites and blends from leather industry waste

Blends based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene‐co‐vinyl acetate) (EVA), were obtained by reactive blending and their physico‐chemical properties as well as their mechanical and rheological behavior were evaluated. The effect of vinyl acetate content and of a transesterification agent added to increase interaction between polymer and bio‐based components were investigated. Novel biodegradable polymeric materials for spray mulching coatings were also obtained from hydrolyzed proteins and end‐functionalized poly(ethylene glycol) (PEG), which was used as crosslinking agent. These products, almost entirely obtained from renewable sources, represent a new type of biodegradable material which looks promising for several applications, for instance in packaging or in agriculture as transplanting or mulching films with additional fertilizing action of PH. POLYM. COMPOS., 37:3416–3422, 2016. © 2015 Society of Plastics Engineers     

Edible Bioactive Film with Curcumin: A Potential “Functional” Packaging?

Edible packaging has been developed as a biodegradable and non-toxic alternative to traditional petroleum-based food packaging. Biopolymeric edible films, in addition to their passive protective function, may also play a bioactive role as vehicles for bioactive compounds of importance to human health. In recent years, a new generation of edible food packaging has been developed to incorporate ingredients with functional potential that have beneficial effects on consumer health. Curcumin, a bioactive compound widely used as a natural dye obtained from turmeric rhizomes (Curcuma longa L.), has a broad spectrum of beneficial properties for human health, such as anti-inflammatory, anti-hypertensive, antioxidant, anti-cancer, and other activities. To demonstrate these properties, curcumin has been explored as a bioactive agent for the development of bioactive packaging, which can be referred to as functional packaging and used in food. The aim of this review was to describe the current and potential research on the development of functional-edible-films incorporating curcumin for applications such as food packaging.     

Development of sulfated polysaccharide-based film reinforced with seaweed biomass-derived nanofillers

Cling films and single-use plastics are difficult to recycle and cause major environmental pollution, leading to an increase in microplastics in nature. To overcome this issue, biodegradable films are being explored more extensively. Seaweed is gaining prominence in the food packaging sector since it is beneficial in all aspects. Two fractions of Indian brown seaweed Sargassum wightii, biopolymer (sulfated polysaccharide [SP]) as base material and nanofillers (cellulose nanocrystals [CNC]) as reinforced filler are employed to develop a sustainable cling film for food packaging. This cellulose filler can be isolated from solid seaweed biomass after the polysaccharide extraction and converted into nanoform using the response surfaces method (RSM) to maximize the yield of CNC. The objective of this research is to construct seaweed-based biodegradable nanocomposite films and to examine their improved properties. It exhibited a gradual decrease in water absorption and water vapor permeability (WVP), along with better wettability, mechanical, and antioxidant properties, and thermal analysis compared with the control SP film. The degradation rates of the films were analyzed using the soil-burial method. According to the results obtained, it is suggested that CNC can be utilized as a functional filler to improve the qualities of seaweed-based cling films.