Green Technologies for Innovative Materials Production for Active Food Packaging

The Food and Agriculture Organization (FAO) reports that 1.6 billion tons of food are wasted every year in the world, which corresponds to about 1/3 of all food production destined for human consumption. Food waste weighs on a global level as it brings with it a series of problems related to resources such as water, land, energy, labor, capital, the mismanagement of which entails an economic burden of about 680 billion dollars in industrialized countries. The food products most subjected to waste are the fresh ones, with a shelf-life of a few days and the products for which the cold chain is required, such as refrigerated and frozen foods. However, for the latter products, compliance with the cold chain along the entire distribution line cannot unfortunately be guaranteed. These impacts derive both from the unreliable management of transport and marketing, and from the limited thermal insulation capacity of traditional materials such as plastic and cardboard. Furthermore, in parallel with food waste, the second global problem is the increase and accumulation of waste deriving from disposable food packaging of fossil origin. In fact, with increasing industrialization, food and packaging have become a single system whereby if one is wasted, the other is wasted as well. In fact, just think that from the 1950s to 2015, plastics production reached 8.3 billion tons, throwing away about 6.3 billion in nature, of which 79% ended up in landfills and in natural environments, 12% was incinerated and only 9% was recycled. In recent years the situation has improved, in fact, in 2020, according to Eurostat data, 23% of plastic waste produced in Europe ended up in landfills, 42% was incinerated and 35% was recycled. However, these data also show that the objectives set by the European Union, namely the achievement of 50% plastics recycling by 2025 and 55% by 2030 are still far. This demonstrates how the use of biodegradable polymers or biopolymers is increasingly becoming a need rather than a choice. Hence the need to find solutions to minimize if not cancel the effects of these two problems. A potential solution is offered precisely by packaging, conceived not in the traditional sense of the term, i.e., as systems for the containment and generic protection of food from the external environment, but in an innovative way for which packaging has become the protagonist and not a passive part of the food product. With this in mind, the so-called active packaging is designed with the aim of interacting in a controlled way with food in order to preserve its nutritional properties, organoleptic properties and extend its shelf-life, all in a safe way for the consumer and for the manufacturer. To perform this function, active packaging is designed through the incorporation of components capable of releasing or absorbing substances from packaged foods or from the environment surrounding the product and, moreover, systems defined as intelligent packaging allow to monitor the quality of products in real time. Among active packaging, antimicrobial and antioxidant films appear to be the most promising to achieve these goals. While, there is little literature on packaging capable of preserving food from sudden changes in temperature, but a possible approach to control and maintain a desired temperature, for a limited period of time, seems to be represented by the thermal energy storage approach. Therefore, this Ph.D. work was aimed at developing films based on natural polymers, such as the protein zein and the polysaccharide chitosan, and synthetic but biodegradable polymers such as polycaprolactone to investigate the potential of these materials to be used as active packaging. The polymeric matrices obtained were then functionalized by adding natural active ingredients such as vanillin, present in vanilla pods, characterized by antimicrobial activity, spent coffee grounds extract, rich in caffeine and polyphenols, alpha-tocopherol, contained in olive oil with high antioxidant properties and finally, natural phase change materials such as fatty acids to study the feasibility of developing packaging materials with thermal insulation properties. For film production, traditional methods, such as extrusion and molding, are mainly based on the direct loading strategy. However, these techniques have some drawbacks related to the use of toxic and polluting solvents, high temperatures, low penetration of the active agent into the polymeric substrate and reduced loading efficiencies. For this reason, several greener techniques have been investigated, more suitable for the treatment of natural substances, such as electrospinning, solvent casting and spin coating. Only solvents accepted by the Food and Drug Administration were selected for treatment. Furthermore, the use of an indirect loading technique, the impregnation with supercritical fluids, for the loading of the active agents subsequent to the production of the polymeric supports was also studied. The obtained products were characterized mainly in terms of morphology, migration tests in different food simulants, gas barrier properties, mechanical tests and functional activities through the comparison of the materials and techniques used. The results obtained made it possible to identify the strengths and limitations of both the materials and the techniques used. However, it was possible to identify a potential intended use for all the materials optimized and identify possible improvement methods to upgrade these materials. Finally, the economic feasibility of the antimicrobial constructs produced by electrospinning through the production of a business plan was assessed.

Smart ECM-Based Electrospun Biomaterials for Skeletal Muscle Regeneration

none9sìThe development of smart and intelligent regenerative biomaterials for skeletal muscle tissue engineering is an ongoing challenge, owing to the requirement of achieving biomimetic systems able to communicate biological signals and thus promote optimal tissue regeneration. Electrospinning is a well-known technique to produce fibers that mimic the three dimensional microstructural arrangements, down to nanoscale and the properties of the extracellular matrix fibers. Natural and synthetic polymers are used in the electrospinning process; moreover, a blend of them provides composite materials that have demonstrated the potential advantage of supporting cell function and adhesion. Recently, the decellularized extracellular matrix (dECM), which is the noncellular component of tissue that retains relevant biological cues for cells, has been evaluated as a starting biomaterial to realize composite electrospun constructs. The properties of the electrospun systems can be further improved with innovative procedures of functionalization with biomolecules. Among the various approaches, great attention is devoted to the "click" concept in constructing a bioactive system, due to the modularity, orthogonality, and simplicity features of the "click" reactions. In this paper, we first provide an overview of current approaches that can be used to obtain biofunctional composite electrospun biomaterials. Finally, we propose a design of composite electrospun biomaterials suitable for skeletal muscle tissue regeneration.openPoliti, Sara; Carotenuto, Felicia; Rinaldi, Antonio; Di Nardo, Paolo; Manzari, Vittorio; Albertini, Maria Cristina; Araneo, Rodolfo; Ramakrishna, Seeram; Teodori, LauraPoliti, Sara; Carotenuto, Felicia; Rinaldi, Antonio; Di Nardo, Paolo; Manzari, Vittorio; Albertini, Maria Cristina; Araneo, Rodolfo; Ramakrishna, Seeram; Teodori, Laur

Smart ECM-based electrospun biomaterials for skeletal muscle regeneration

The development of smart and intelligent regenerative biomaterials for skeletal muscle tissue engineering is an ongoing challenge, owing to the requirement of achieving biomimetic systems able to communicate biological signals and thus promote optimal tissue regeneration. Electrospinning is a well-known technique to produce fibers that mimic the three dimensional microstructural arrangements, down to nanoscale and the properties of the extracellular matrix fibers. Natural and synthetic polymers are used in the electrospinning process; moreover, a blend of them provides composite materials that have demonstrated the potential advantage of supporting cell function and adhesion. Recently, the decellularized extracellular matrix (dECM), which is the noncellular component of tissue that retains relevant biological cues for cells, has been evaluated as a starting biomaterial to realize composite electrospun constructs. The properties of the electrospun systems can be further improved with innovative procedures of functionalization with biomolecules. Among the various approaches, great attention is devoted to the “click” concept in constructing a bioactive system, due to the modularity, orthogonality, and simplicity features of the “click” reactions. In this paper, we first provide an overview of current approaches that can be used to obtain biofunctional composite electrospun biomaterials. Finally, we propose a design of composite electrospun biomaterials suitable for skeletal muscle tissue regeneration

Bidirectional optimization of the melting spinning process

This is the author's accepted manuscript (under the provisional title "Bi-directional optimization of the melting spinning process with an immune-enhanced neural network"). The final published article is available from the link below. Copyright 2014 @ IEEE.A bidirectional optimizing approach for the melting spinning process based on an immune-enhanced neural network is proposed. The proposed bidirectional model can not only reveal the internal nonlinear relationship between the process configuration and the quality indices of the fibers as final product, but also provide a tool for engineers to develop new fiber products with expected quality specifications. A neural network is taken as the basis for the bidirectional model, and an immune component is introduced to enlarge the searching scope of the solution field so that the neural network has a larger possibility to find the appropriate and reasonable solution, and the error of prediction can therefore be eliminated. The proposed intelligent model can also help to determine what kind of process configuration should be made in order to produce satisfactory fiber products. To make the proposed model practical to the manufacturing, a software platform is developed. Simulation results show that the proposed model can eliminate the approximation error raised by the neural network-based optimizing model, which is due to the extension of focusing scope by the artificial immune mechanism. Meanwhile, the proposed model with the corresponding software can conduct optimization in two directions, namely, the process optimization and category development, and the corresponding results outperform those with an ordinary neural network-based intelligent model. It is also proved that the proposed model has the potential to act as a valuable tool from which the engineers and decision makers of the spinning process could benefit.National Nature Science Foundation of China, Ministry of Education of China, the Shanghai Committee of Science and Technology), and the Fundamental Research Funds for the Central Universities

Self-healing composites: A review

Self-healing composites are composite materials capable of automatic recovery when damaged. They are inspired by biological systems such as the human skin which are naturally able to heal themselves. This paper reviews work on self-healing composites with a focus on capsule-based and vascular healing systems. Complementing previous survey articles, the paper provides an updated overview of the various self-healing concepts proposed over the past 15 years, and a comparative analysis of healing mechanisms and fabrication techniques for building capsules and vascular networks. Based on the analysis, factors that influence healing performance are presented to reveal key barriers and potential research directions

Electrospun Poly(ethylene-co-vinyl alcohol)/Graphene Nanoplatelets Composites of Interest in Intelligent Food Packaging Applications

Graphene nanoplatelets (GNPs) were synthetized from graphite powder and, thereafter, embedded in poly(ethylene-co-vinyl alcohol) (EVOH) fibers by electrospinning in the 0.1-2 wt.-% range. The morphological, chemical, and thermal characterization performed on the electrospun nanocomposite fibers mats revealed that the GNPs were efficiently dispersed and rolled along the EVOH fibrilar matrix up to contents of 0.5 wt.-%. Additionally, the dielectric behavior of the nanocomposite fibers was evaluated as a function of the frequency range and GNPs content. The obtained results indicated that their dielectric constant rapidly decreased with the frequency increase and only increased at low GNPs loadings while the nanocomposite fiber mats became electrically conductive, with the maximum at 0.5 wt.-% GNPs content. Finally, the electrospun mats were subjected to a thermal post-treatment and dark films with a high contact transparency were obtained, suggesting that the nanocomposites can be used either in a nonwoven fibers form or in a continuous film form. This study demonstrates the potential of electrospinning as a promising technology to produce GNPs-containing materials with high electrical conductivity that can be of potential interest in intelligent packaging applications as 'smart' labels or tags

Sustainable electrospinning of nanoscale fibres

Electrospinning is an effective technology for the preparation of nano and micro scale fibres for diverse application in oil recovery, medical devices, and filters. It is achieved by injecting a charged solution of polymeric material through a needle into a region of high electric field. Under these conditions, the expelled jet follows a chaotic, whip-like trajectory towards a grounded collection plate. At low polymer concentrations, the high forces experienced by the jet prior to becoming grounded on the collection plate, result in the formation of undesirable discrete droplets of material, rather than fibres. At higher concentrations, above the critical entanglement limit for the polymer, the polymer chains are stretched and orientated whilst the solvent rapidly evaporates, delivering high aspect ratio fibres. The resulting mesh of overlapping fibres frequently has useful properties such as high surface area and porosity, which has led to their investigation for a range of applications including filtration membranes and tissue scaffolds. One of the major challenges in the development of electrospinning as a manufacturing technology is the use of organic solvents. Typically fibres are spun from relatively dilute solutions containing 95% solvent. It is clear that systems which use water as a solvent offer many advantages in terms of safety, cost and sustainability. In this work we optimise the conditions for effectively preparing nano/micro fibres of polyethylene oxide from aqueous solutions. We contrast the fibres produced with those prepared using volatile organic solvents

A review on nanocellulosic fibres as new material for sustainable packaging: process an applications

The demand for exploring advanced and eco-friendly sustainable packaging materials with superior physical, mechanical and barrier properties is increasing. The materials that are currently used in packaging for food, beverage, medical and pharmaceutical products, as well as in industrial applications, are non-degradable, and thus, these materials are raising environmental pollution concerns. Numerous studies have been conducted on the utilization of bio-based materials in the pursuit of developing sustainable packaging materials. Although significant improvements have been achieved, a balance among environmental concerns, economic considerations and product packaging performance is still lacking. This is likely due to bio-based materials being used in product packaging applications without a proper design. The present review article intends to summarize the information regarding the potential applications of cellulosic nanofiber for the packaging. The importance of the design process, its principles and the challenges of design process for sustainable packaging are also summarized in this review. Overall it can be concluded that scientists, designers and engineers all are necessarily required to contribute towards research in order to commercially exploit cellulose nanofiber for sustainable packaging

Factories of the Future

Engineering; Industrial engineering; Production engineerin