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The aim of the present study was to investigate starch-based materials, prepared in an environmentally friendly way and from renewable resources, suitable for the development of biodegradable active food packaging. For this purpose, a bioactive compound (thymol) was incorporated into thermoplastic starch (TPS) and a TPS blend with poly (ε-caprolactone) (TPS–PCL) by the supercritical CO2 (scCO2) impregnation process. Impregnation experiments with scCO2 were carried out at a pressure of 30 MPa and temperatures in the range of 40–100 °C during 1 to 20 h. The structural, morphological, and thermal properties of the obtained materials were comprehensively evaluated. Bioactive component release kinetic studies were performed in water at 6 °C and 25 °C. It was shown that the scCO2 impregnation process could be successfully employed for thymol loading into TPS and TPS–PCL. The process was significantly influenced by the operating temperature and time as well as content of PCL. The samples showed a controlled release of thymol within seven days with a higher amount of released thymol from the TPS–PCL blend. The obtained materials are solvent-free and release the bioactive component in a controlled manner.

Bio-based composites made of poly(L-lactic acid) (PLLA) and β-cyclodextrin/d-limonene inclusion complex (CD-Lim) were prepared by melt extrusion. Encapsulation of volatile d-limonene molecules within β-cyclodextrin cages was proven to be a successful strategy to prevent evaporation during high-temperature processing. However, small amounts of limonene were released upon processing, resulting in the plasticization of the polymeric matrix. Morphological analysis revealed good dispersion of the filler, which acted as a nucleating agent, favoring the growth of PLLA crystals. The composites′ lowered glass transition temperature upon the addition of CD-Lim was also proved by thermomechanical analysis (DMA). Moreover, DMA revealed constant stiffness of modified materials at room temperature, which is crucial in PLLA-based formulations.

In this study, mixtures based on β-glucans and proteins are extracted from barley, in mild (MA) and high (HA) alkaline conditions, and employed with zinc oxide (ZnO) to prepare bioactive films for wound healing. Composition of extracts and properties of resulting films depend on pH extraction conditions. MA based samples show weak physical interactions among mixture components, whereas in HA films the extent of these interactions is larger. Consequently, their chemico-physical properties are significantly different, as demonstrated by FT-IR, thermal, mechanical and morphological analyses. ZnO with its bound water molecules acts as a slight plasticizer in MA, as shown by the lower Tg and the decrease of elastic modulus. In HA, this effect is evidenced up to ZnO 1%, and above this concentration an increase of strength at break is observed. Finally, MA and HA films show intrinsic antimicrobial properties, enhanced by ZnO, which make them exploitable as wound dressings.

Introduction Barley is one of the most produced and cultivated cereal crops worldwide. Its grains are mainly composed by proteins and polysaccharides, in particular ?-glucans that are linear polysaccharides showing hypocholesterolemic and hypoglycemic activity and having interesting antimicrobial and wound healing properties. However, the process of extraction and purification for isolating ?-glucans from the other components is complex, expensive and may cause polymer chain degradations. In light of this, the aim of this work was the development of low-cost simultaneous extractions of proteins and polysaccharides from barley by-products, to prevent polymer degradation. It is well known that ZnO is widely used to prevent or treat topical and systemic diseases, due to its antimicrobial activity. Therefore, films based on different polysaccharide and protein extracted mixtures were prepared with and without ZnO to get cost-effective bioactive wound dressings.

Compression molded biodegradable films based on poly(butylene succinate) (PBS) and poly(butylene adipate-co-terephthalate) (PBAT) at varying weights were prepared, and their relevant properties for packaging applications are here reported. The melt rheology of the blends was first studied, and the binary PBS/PBAT blends exhibited marked shear thinning and complex thermoreological behavior, due to the formation of a co-continuous morphology in the 50 wt% blend. The films were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests, scanning electron microscopy (SEM), and oxygen and water vapor permeability. PBS crystallization was inhibited in the blends with higher contents of PBAT, and FTIR and SEM analysis suggested that limited interactions occur between the two polymer phases. The films showed increasing stiffness as the PBS percentage increased, further, a sharp decrease in elongation at break was noticed for the films containing percentages of PBS greater than 25 wt%. Gas permeability decreased with increasing PBS content, indicating that the barrier properties of PBS can be tuned by blending with PBAT. The results obtained point out that the blend containing 25 wt% PBS is a good compromise between elastic modulus (135 MPa) and deformation at break (390%) values. Overall, PBS/PBAT blends represent an alternative for packaging films, as they combine biodegradability, good barrier properties and reasonable mechanical behavior.

In this work, α−costic acid (α-CA), a metabolite coming from a perennial autochthon shrub Dittrichia viscose, was used as natural additive of polylactic acid (PLA), a biodegradable thermoplastic polymer, in order to modulate its chemico-physical properties, for the achievement of a wholly biobased packaging system. It’s the first time that α−costic acid is exploited for this appealing and novel application. The investigations performed on PLA/α-CA films, evidenced strong physical interaction occurring between the polymer and α-CA, as confirmed by NMR and FTIR-ATR analyses; SEM micrographs showed a good embedding of α-CA particles inside PLA polymer matrix; GPC analysis highlighted a slight hydrolysis of polymer matrix clearly evidenced in mechanical properties. DSC analysis underlined the significant decreasing of Tg, associated with the increase of PLA chain mobility. TGA thermograms evidenced one broad degradation profile of PLA/α-CA system, accounting for the weighty physical interaction occurring between the polar groups of both polymer and plasticizer. Finally, PLA surface wettability notably enhanced by the inclusion of α-CA polar groups. In conclusion, α-CA can be considered as a promising plasticizer of PLA and a worthy modifier of its overall properties.

In this study, chitosan (C) tripolyphosphate (T) sub-micro particles containing ungeremine (CTUn), an alkaloid particularly active against Penicillium roqueforti, a fungus responsible of the bakery products deterioration, were prepared through external gelation crosslinking process. The particles were included in a thermoplastic starch based polymer Mater-Bi (MBi), and MBi/CTUn bioactive biocomposites were obtained. The films showed bioactivity against P. roqueforti. In particular, the bioassays were performed on films with different concentration of CTUn and at different pH values. CTUn particles influenced MBi crystallization (DSC analysis) and promoted thermal degradation of MBi starch component (TGA). Morphological analysis confirmed even distribution of sub-micro particles into the polymeric matrix. Water permeability slightly increased, as expected, whereas oxygen permeability decreased. Tensile tests showed CTUN sub-microparticles improved rigidity and tensile strength of the films at the expense of ductility. Finally, MBi/CTUn biocomposites evidenced interesting performances potentially exploitable in bioactive bakery based food packaging materials.

A pectin coated dehydrated apple snack containing ≥9 log colony forming units/20 g portion of the probiotic Lactobacillus paracasei IMPC2.1, was developed. The strain was incorporated into the apple slices using vacuum impregnation (IP1) or soaking/stirring (IP2); apple slices were then coated with citrus pectin and dehydrated at 4 °C for 14 days. Microbial application led to colonization of the apple surface, as seen using scanning electron microscope images, and all probiotic products showed comparable radical scavenging activity and total phenol content. IP2 led to better bacterial survival during 30 days storage at 4 °C and color parameters comparable to the fresh apple. The simulated gastro-intestinal (GI) digestion suggested the ability of the strain to survive the digestive process. This inclusion/coating/dehydration process led to a probiotic snack, which could successfully deliver bacterial cells in a viable form to the GI tract.

One of the greatest problems in food packaging system is prevention of food from the mold contamination. In particular, in the bakery products Penicillium roqueforti (PR) is the main contaminator associated to the food deterioration. Food packaging systems are responsible to protect food substrate from physical damage, chemical and biological contaminations. In addition, packages are designed to preserve the food quality and safety, extending their shelf-life. However, finalized to enhance the food packaging performances recently, the attention of research and industrial partnerships is increasingly focused on bioactive packaging. Antimicrobial food packaging is based on the incorporation of natural bioactive metabolites into polymer or biopolymer matrices, acts to reduce, inhibit or hinder the growth of microorganisms able to develop not only in the food but also in the packaging material itself. In particular, some plants material showed antifungal activity with potential application in food packaging. In this respect, ungeremine (Un) is one of the most active plant metabolites against P.roqueforti. Ungeremine is a betaine type alkaloids isolated from Pancratium maritimim L., a well knows species of Amaryllidaceae collected on Egypt northern coasts. Ungeremine was also obtained from SeO2 oxidation of lycorine, the main Amaryllideacea alkaloids. In this study, chitosan (Ch) based sub-micro particles containing ungeremine were prepared by using sodium tripolyphosphate (TPP) and formulated into Mater-Bi (MBi) polymer matrix. The Ch_TPP_Un/MBi composites were obtained by compression molding. The bioassay result of the films evidenced their activity against P.roqueforti. In addition, determination of residual ungeremine into films after 72h inhibition showed that, depending on the different food substrate pH, the diverse releasing pattern of fungicide from the package system could be expected. The morphological analysis confirmed a homogeneous distribution of sub-micro particles into MaterBi polymer matrix. The tensile test analysis showed that sub-micro particles could significantly decrease the ductility and slight increase in the elastic modulus of the films. Finally, thermogravimetric analysis confirmed specific physical interaction between chitosan based sub-microparticles and the starch fraction of MBi which, in turn, resulted in a decrease of thermal stability of MBi starch segments.

One of the greatest problems in food packaging system is the prevention of food from the mold contamination. Indeed, food mold infestation is very dangerous for human health and also can considerably increase the financial cost. In particular, in the bakery products, Penicillium roqueforti and Aspergillus niger are the main contaminators. On the other hand, food packaging systems are responsible to protect food substrate from physical damage, chemical and biological contaminations. In addition, packages are designed to preserve the food quality and safety, extending their shelf-life. However, due to environmental impact of the conventional polymers recently, the attention of researchers and industrial sectors are mainly on bioactive packaging by using bio polymer based package system. Antimicrobial food packaging known as active packing is based on the incorporation of natural bioactive metabolites into the polymer or biopolymer matrices to reduce, inhibit or hinder the growth of microorganisms on the packaged food. In particular, some plants material showed antifungal activity with potential application in food packaging. This project assayed the inhibitory activity of 13 bacterial, fungal and plant metabolites against P.roqueforti and A.niger and selected the most active ones which were cavoxin, ungeremine and ?-costic acid. The potential application of those natural metabolites into bio packaging system was investigated by the formulation of those metabolites into the biopolymer matrix in order to obtain active packaging system to increase the quality of food packaging, the food shelf-life, and microbiological safety.

Cardoon seed oil (CO), derived from the nonedible Cynara cardunculus plant, growing in marginal and contaminated soils of Mediterranean regions, was successfully epoxidized (ECO) in a fed-batch modality. The cost-effective and environmentally friendly oils have been used as bioplasticizers of poly(lactic acid) (PLA), to improve the overall properties and broaden its industrial applications as a biodegradable packaging material. Hence, physical blends and films of PLA, containing 3% by weight of CO and ECO, were prepared by melt extrusion and compression molding, and the effect of the both bioplasticizers on structural, thermal, and mechanical properties of the obtained films was investigated. Cardoon oils induced the decreasing of glass transition temperature due to PLA free volume enhancement. This effect was particularly marked in PLA–ECO film. Thermal stability of PLA was meaningfully improved upon addition of the oils, and the mechanical properties made evident the increase of PLA ductility, particularly enhanced in the PLA–ECO system, where the polymeric matrix and the oil showed stronger physical interaction and improved phase compatibility, as also revealed by spectroscopic and morphological analyses. Therefore, the plasticization action exerted by very low concentrations of epoxidized cardoon oil efficiently overcomes PLA drawbacks, thus encouraging the feasibility of its use as a bioplastic for packaging material.

Active packaging refers to packaging systems with active functions beyond the inert passive containment and protection of the product. It is commonly used with foods, as it helps extend shelf life, improve safety or sensory properties and maintain food quality [1]. Most diffused active packaging systems include the use of oxygen scavengers, carbon dioxide or ethylene emitters and scavengers, ethanol releaser, as well as antimicrobial and antioxidant agents. The active agent may be placed in the package with the food, within a small sachet or pad of permeable material, able to release volatile antimicrobial agents without allowing a direct contact with the food product. Incorporation of volatile active agents into polymers is a technological challenge, due to the need to avoid evaporation of the additive during melt processing of the polymer. Such challenge can be solved by incorporation of the volatile molecules within cyclodextrins (CD), as detailed in this contribution. Cyclodextrins are biocompatible, biodegradable cyclic oligosaccharides produced from a renewable natural material, starch [2]. Cyclodextrins can form inclusion complexes with various non-polar, aliphatic and aromatic compounds, including antibacterial molecules, whose release could enhance the quality of the packaged product and extend its shelf life [3]. In the research detailed below, b-CD was used as cage to include D-limonene (4-isopropenyl-1-methylcyclohexene), the major constituent in several citrus-derived essential oils, which is also a natural antimicrobial agent [4-6]. D-limonene is listed in the Code of Federal Regulations and generally recognized as safe flavoring agent and food preservative [7]. Its outstanding antimicrobial activities have already been tested with different species of food-related microorganisms, such as staphylococcus aureus, Listeria monocytogenes, Salmonella enterica, Saccharomyces bayanus [8, 9]. Unfortunately, D-limonene is susceptible to oxidative degradation, which directly results in its loss of activity [7, 10]. Moreover, similar to other volatile essential oils, limonene aroma could be easily released to the packaged food, thus contaminating it. In order to overcome to these drawbacks, D-limonene was included into CDs, and the inclusion complex CD-Lim thus obtained was dispersed into a biodegradable and bio-based polymer matrix, namely poly(butylene succinate) (PBS). PBS is a biodegradable and bio-based polyester, currently used for food packaging, and its use in this market area is expected to largely increase in the coming years [11]. The aim of this paper is to prepare a novel biodegradable polymeric-based system, as potential bioactive food packaging material, by dispersing CD-Lim inclusion complex into PBS polymeric matrix and to investigate the chemical-physical properties of the obtained blends.

Biodegradable polymer films based on polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT) blends with varying weight ratios were prepared by extrusion and chill roll calendering. The films were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests, scanning electron microscopy (SEM), and rheology. In the blends with higher content of PBAT, PBS crystallization was inhibited. As for mechanical performance, increasing the PBS content in PBAT an increase in the stiffness and a decrease in the ductility of the blends is detected. Finally, rheological measurements evidence an increase in the viscosity of the blends with increasing the PBAT content.

Ungeremine is a betaine type alkaloid isolated from Pancratium maritimim L., 1 and thus could be synthesized by SeO2 oxidation of lycorine, which is the main Amaryllideacea alkaloid obtained in high yield from Sterbergia lutea Ker Gawl. a wild species coollected on the coasts Apulia region in South Italy. 2 Ungeremine have shown a very significant antifungal activity against Penicillium roqueforti,3 a filamentous fungus responsible of the bakery products deterioration. In this study, chitosan based microbeads containing ungeremine, were prepared by external gelation by using sodium tripolyphosphate (TPP) as crosslinking agent. The stability of the microbeads, as well as the loading efficiency of the antifungal metabolite were assessed at different pH and TPP concentrations and resulted particularly enhanced at low pH. All the microbeads evidenced antimicrobial activity against Penicillium roqueforti. The release kinetics of ungeremine was tailored by opportunely modulating pH and TPP concentrations. Morphological analysis evidenced the improvement of the structural cross linking density of microbeads including ungeremine and spectroscopic analysis emphasized the active participation of ungeremine to the crosslinking process occurring between chitosan and TPP. Finally, thermogravimetric analysis confirmed the increasing of free volume in threedimensional networks and their liability to thermal degradation.

In this paper, a novel and sustainable process for the fruit dehydration was described. Specifically, edible coatings based on pectin and honey were prepared and used as dehydrating and antimicrobial agents of cut fruit samples, in this way promoting the fruit preservation from irreversible deteriorative processes. Pectin-honey coating was tested on apple, cantaloupe melon, mango and pineapple. The analysis were performed also on uncoated dehydrated fruits (control). The coated fruit evidenced enhanced dehydration percentage, enriched polyphenol and vitamin C contents, improved antioxidant activity and volatile molecules profile. Moreover, the antimicrobial activity against Pseudomonas and Escherichia coli was assessed. Finally, morphological analysis performed on fruit fractured surface, highlighted the formation of a non-sticky and homogeneous thin layer. These outcomes suggested that the novel fruit dehydration process, performed by using pectin-honey coating, was able to both preserve the safety and quality of dehydrated fruits, and enhance their authenticity and naturalness.

In this study, pectin based films including different amounts of sodium alginate were prepared by casting method. All the films, with and without polyglycerol as plasticizer, were crosslinked with zinc ions in order to extend their potential functionality. The development of junction points, occurring during the crosslinking process with zinc ions, induced the increasing of free volume with following changing in chemico-physical properties of films. The inclusion of alginate in pectin based formulations improved the strength of zinc ions crosslinking network, whereas the addition of polyglycerol significantly improved mechanical performance. Finally, zinc-crosslinked films evidenced antimicrobial activity against the most common exploited pathogens: Staphylococcus Aureus, Escherichia Coli and Candida Albicans. These results suggest that zinc-crosslinked based films can be exploitable as novel bio-active biomaterials for protection and disinfection of medical devices. (C) 2016 Elsevier Ltd. All rights reserved.

A study carried out by the European Council in 2010 established that every year about 179 kg of food per person (about 90 million tons) are wasted in Europe. New strategies for research, innovation and player awareness are required along the entire food chain to fight chain losses and contribute to food chain sustainability. Food waste can be attributed to all and every chain stakeholder, according to the following breakdown: 42% in the households, 39% producers, 5% retailers and 14% catering. Considering that food is wasted throughout the whole supply chain there must be a coordinated strategy aimed at improving the efficiency, sector by sector, to the final consumer. By promoting an effective collaboration between enterprises - Whirlpool, Bolt di Stefano Palmese (Pomigliano D'Arco -NA), F.lli Naddeo srl (Scafati - SA), Rago - Az. Agricola "I Pini" di Rago Rosario (Battipaglia -SA) , - and research organizations - CNR- ISPA, CNR-ISA; CNR-ICTP and CREA-ZA -, activities scheduled meet the strategic objective to develop innovative technology solutions for sustainable food processing and preservation. To face domestic losses, the phase where food is to a significant extent wasted, the knowledge of perishability of food matrices when associated to the home environment and to the thermal history of products, can provide important information on the quality and edibility of the food. This would be very useful for home food managing, by balancing the erroneous association between appearance and intrinsic quality, which heavily influences consumer's choice. Changes in appearance and quality are associated with chemical and physical mutations due to incorrect storage conditions and/or microbiological factors. The computational modeling allows to describe and predict the evolution of food during storage as a function of environmental conditions. All information about food, its history and its edibility, can help the home management of refrigerated foods. Therefore, the development of new solutions capable of supporting the consumer in the management of the storage of foodstuffs will assist consumers to reduce/minimize waste related to the home management of food. Innovative solutions at production, postharvest and processing stages may also have a pivotal role in food preservation and food chain sustainability. The development of environmentally friendly packaging film containing antimicrobial "food grade" agents, as well as the application of sustainable technologies for the dehydration of food products by using biocompatible and biodegradable polymers, can well contribute in preventing food spoilage and prolonging product shelf-life. Anyway, also the packaging systems contribute to produce waste. Therefore, research goes with no little difficulty toward "green label" systems of preservation which are of vegetable origin and activated by natural substances. In the perspective of really sustainable supply chain, it would be very desirable to improve the efficiency of processes. Particularly, energy and water saving is essential for achieving the targets of greenhouse gas emissions reduction. However, this option has to face the real availability of effective and environmentally friendly technologies for energy intakes reduction. An integrated drying process of fresh-cut vegetables, assisted by ultrasonic power and associated with energy recovery devices, is being developed in the project. In the transformation of vegetable foods, fresh-cut vegetables are characterized by a considerable tendency to perish in relation to the risk of microbial spoilage. The ultrasonic-associated drying process would optimize existing technologies since ultrasounds fasten water removal from the produce before packaging and results feasible as an alternative or in combination with traditional methods. Furthermore, new solutions for the valorization and exploitation of wasted biomass of fresh-cut vegetables industry, through composting and recycling them into the production system, may represent the substrate for composting company through a simple so-called "on-farm" system. Finally, also at the production level, new strategies are applied for fertigation of soilless crops. Nutrient solution recycling improves the efficiency of water, greatly simplifying crop management and reducing environmental impact. The employment of new methods and technological solutions for the improvement of the sustainability in the national Agrifood chain will give an important contribution to meet the sustainability goals established at European Level.

Structural, morphological and thermal properties of films based on poly(butylene succinate) (PBS) and inclusion complex (IC) of beta-cyclodextrins (beta-CD) and D-limonene were studied, in order to prepare novel bio-active food packaging materials. Formation of the inclusion complex was proved by infrared spectroscopy, nuclear magnetic resonance, and X-ray diffraction. The IC contains 7 wt% of D-limonene, as quantified by precipitation, as well as by C-13 NMR and by thermogravimetry. Inclusion within beta-CD cavity stabilizes D-limonene against evaporation, which allows melt compounding with PBS. Infrared spectroscopy of compression molded composite films, evidenced both the D-limonene encapsulation inside beta-CD cages, and the occurrence of interactions between hydroxyl groups of beta-CD-lim complex and the carbonyl groups of PBS units. Optical micrographs showed a phase separated morphology, with homogeneous distribution of the IC within the PBS matrix, probably due to interactions between the polar groups of the composite components. DSC analysis highlighted the anti-nucleating action of beta-CD-lim complex towards PBS, evidenced by a significant delay in crystallization kinetics of PBS. (C) 2016 Elsevier Ltd. All rights reserved.

Vegetable biomass is one of the most promising renewable source of energy and chemicals. Indeed, its exploitation for biofuel and commodity chemicals has been the focus of research over the last years and the gradual shift toward the so-called bio-based economy (an economy system based on exploitation of renewable resources) has determined a global increasing demand for goods mainly derived from vegetable biomass. In order to ensure a more sustainable productivity and the global food security, wastes coming from cultivation, harvesting and processing of vegetables have been recently considered as an alternative source for biomolecules and bioenergy that can find application in several industrial areas. According to this global scenario, the possible exploitation of the residual biomass coming from the industrial processing of lemon (Citrus limon), tomato (Lycopersicon esculentum var. ''Hybrid Rome''), fennel (Foeniculum vulgare var. Dulce) and carrot (Dacus Carota), were studied. These by-products were used as a source of two distinct classes of biomolecules: polysaccharides and polyphenols.

Vegetable biomass is one of the most promising renewable source of energy and chemicals. Indeed, its exploitation for biofuels and chemicals production has been the focus of research over the last years since the gradual shift toward the so-called bio-based economy (an economy system based on exploitation of renewable resources), has determined a global increasing demand for goods mainly derived from vegetable biomass. According to this global scenario, the possible exploitation of the residual biomass coming from the industrial processing of lemon (Citrus limon), tomato (Lycopersicon esculentum var. ''Hybrid Rome''), fennel (Foeniculum vulgare var. dulce) and carrot (Dacus carota), were studied. This work highlighted the biorefining approach for the re-use of such bio-agro-wastes that have been used as sources of two kinds of value added-products i.e polysaccharides and polyphenols whose biotechnological properties and biological activities were investigated.

In this paper we propose an in situ forming ionically cross-linked alginate (Alg) hydrogel delivering a Tea Tree Oil microemulsion (MeTTO) and potentially useful as an advanced dressing for infected wounds. Alg hydrogels were prepared by a spray-by-spray deposition method with the aim to minimize the discomforts during application. From pseudoternary phase diagrams, it was found that proper combination of TTO, water, polysorbate 80 and ethanol gave stable spherical MeTTO with good antimicrobial activity. On this basis, MeTTO at 20% TTO was selected for further inclusion in an Alg hydrogel prepared by alternating sprays of Alg/MeTTO and calcium chloride solutions. Homogeneous dispersion of MeTTO inside cross-linked Alg was assessed by different macroscopic and microscopic methods demonstrating the superior propensity of MeTTO to be integrated in the water-based hydrogel as compared to TTO. Antimicrobial effect of Alg/MeTTO hydrogels on Escherichia Coli strains was remarkable, highlighting the potential of the system as bioactive wound dressing.

A lignin-rich residue (LRR) obtained as a by-product from the fermentative bioethanol production process, and commercial alkali lignin (AL), were used as fillers for the preparation of bio-based blends and composites with poly(3-hydrobutyrate) (PHB). Chemical characterization of LRR demonstrated that the filler contained sugar residues. Rheological and thermal characterization of the blends demonstrated that LRR did not affect thermal stability of PHB, while AL had a strong pro-degrading effect. Addition of suitable amounts of LRR dramatically affected the rheological behavior of the polymer melt, suggesting that the additive can modify polymer processability. LRR was also a heterogeneous nucleating agent, potentially able to control the physical aging of PHB. Lower resilience and elongation at break values were found for the biocomposites, due to the poor interfacial adhesion between filler and matrix. Biodegradation behavior of the composites was qualitatively assessed by analyzing the surface of soil buried films. Significant surface degradation was observed for PHB, while the process was retarded at high filler concentration, as LRR inhibited hydrolytic and biotic polymer degradation. The reported results demonstrated the feasibility of the conversion of an agro-industrial by-product into a bio-resource in an environmentally friendly and cost-effective way. © 2014 Elsevier B.V.

The use of plastic mulching films in horticulture causes the serious drawback of huge amount of wastes to be disposed of at the end of their lifetime. Several pre-competitive research products based on raw materials coming from renewable sources were recently developed to be used as biodegradable materials for soil mulching. Biodegradable materials are designed in order both to retain their mechanical and physical properties during their using time and to degrade at the end of their lifetime. These materials can be integrated directly in the soil in order to biodegrade because the bacterial flora transforms them in carbon dioxide or methane, water and biomass. The innovative materials can be obtained using natural polymers, such as starch, cellulose, chitosan, alginate and glucomannan. Biodegradable extruded mulching films were performed by means of thermo-plasticizing process. Spray mulch coatings were realized directly in field, by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper an overview on the formulation development, processing understanding, field performance, mechanical and radiometric properties of these innovative materials for soil mulching is presented. In field the biodegradable mulching films showed suitable mechanical properties if compared to the low density polyethylene films. The radiometric properties and their effect on the temperature condition and on weed control in the mulched soil were evaluated too. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants.

Wastes and by-products of agro-food industries and paper–textile manufacturing companies, such as tomato peels and seeds, and hemp, were glued with sodium alginate in order to produce biodegradable pots for plant transplanting in agriculture, thus aiming both to reduce such wastes and also to fight the accumulation of plastic pot wastes produced in plant nurseries. Laboratory tests performed on polysaccharide films and biocomposites based sheets prepared with the same materials developed for preparing the pots, were carried out in order to understand the chemico-physical correlations between resin, ionic crosslinking agent, reinforcing fibres and water. To this aim, mechanical tests, water vapour permeability tests, water up-take evaluations and morphological analysis were carried out. It was found a strong physical interaction between sodium alginate and calcium ions in the development of a three-dimensional network. The crosslinked structure was able to physically entrap the reinforcement fibres by means of hydrogen bonding, as evidenced by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. SEM analysis performed on fracture surfaces of the biocomposites evidenced that the fibres were well embedded inside the three-dimensional network, even if their dispersion needed some improvements; EDS analysis revealed the presence of calcium in rather all the selected internal micro-zones, thus suggesting a well structured network. In order to assess the agronomic performance of the novel biodegradable pots in seedling transplanting activity, the pots were tested in real field condition during 2009 at the experimental farm of the University of Bari, Italy. From the analysis of the young plants transplanted in the field, it was inferred that the biodegradable containers had enhanced the roots plants development and the plant growing, avoiding transplant shock and root deformation. After the using time, they completely degraded into the soil within 2 weeks.

Films of pure sodium alginate and films containing sodium alginate with hydroxyethylcellulose and/or polyglycerol were prepared in order to study their effect on the physical properties. In addition, the films, with different composition, were ionically crosslinked with calcium ions by soaking the films in a solution of calcium chloride. The films containing hydroxyethylcellulose are homogeneous with good mechanical properties. The addition of hydroxyethylcellulose and polyglycerol modifies in a noticeable way some thermal and mechanical parameters, but also the amount of water absorbed in terms of bound water and free water. (C) 2010 Elsevier Ltd. All rights reserved.

An innovative biodegradable coating that can be sprayed was developed and tested as suitable alternative to low density polyethylene (LDPE) films for soil mulching in horticulture. A mulch was created by spraying onto the soil a sodium alginate water-based solution that, at the end of the cultivation cycle, could be tilled into the soil to be biodegraded. The mechanical and radiometric properties, the functionality of the spray coating, and its biodegradation were assessed by means of laboratory measurements and cultivation field tests. In the field, during the cultivation of strawberries, the spray coating was compared with a LDPE mulching film and a straw mulch. The mechanical properties of the coating degraded when exposed in the field, but the coating kept its mulching effect for 6 months. The radiometric properties varied without regular trends, but the coating maintained its capacity to suppress weeds. The biodegradation tests showed that the spray coating samples biodegraded by 65% after 6 months into the soil.

A study of the interaction among sodium alginates of different molecular compositions, water and glycerol was carried out, in order to weigh up the influence of different polymeric microstructures on the chemical-physical properties of films obtained by water soluble blends of sodium alginates and increasing amounts of glycerol. Thermal, mechanical and morphological analyses performed on the films confirmed the existence of specific interactions between sodium alginates and glycerol; it was as well demonstrated that only at specific mass ratio between the single polymers and glycerol it is possible to obtain the correct plasticizing effect induced by glycerol.

The high consumption of plastic materials for use in agriculture is generating serious problems regarding environmental impact. Biodegradable materials are at present the only solution to this type of problems. Research in material science is daily proposing different materials with this requirement for application in various sectors. One of the problems is to analyse the degradation states of the films before their application in order to know the time and the modality of degradation. Here we propose a novel method based on thermography vs time which allows the degradation dynamics of agricultural films to be evaluated. In our experiment we put some biodegradable materials of our interest on soil in an open field. The main characteristic of these materials is that they are originally liquid and they are sprayed on soil and immediately cross-link into a film state. Through an IR thermal camera we monitored the state of the films day by day and analysed the thermal images in order to detect the continuous changing of their physical properties.

Background Biopolymers can be considered a valid alternative to synthetic polymers in the food packaging industry since their biodegradability, biocompatibility, easy renewability, and generally good mechanical properties, comparable with the ones of conventional polymers. Natural secondary metabolites derived from plants and fungi have attracted much attention in the food packaging industry because of their both antimicrobial and antioxidant activity and positive effect on biofilm mechanical performances. Scope and approach Food packaging aims to preserve food quality and safety as well as to extend food shelf-life. Due to the environmental impact of synthetic polymers used in the food packaging industry, academic and industrial research focused the attention on the exploitation of biopolymer-based package systems. Active packaging is a new food packaging path, concentrating on generating a multifunctional system via formulating active agents into the packaging polymer matrices. Secondary compounds of plants and fungal are promising natural additives for active packaging since they can act as antioxidants, antimicrobial, and plasticizer agents. In this review, the antimicrobial, antioxidant, and plasticizing effect of secondary metabolites included in biopolymer-based food packaging materials are described, highlighting their main impact on bioplastics properties. Key findings and conclusions Secondary metabolites (SMs) evidenced antimicrobial and antioxidant activity by inhibiting the growth of pathogenic microorganisms and protect food from oxidation. Besides, depending on the specific formulation, preparation methodology, and physical or chemical interaction occurring between the polymer and additive functional groups, they could provide peculiar effects on the mechanical performances of the biofilms.