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.     

Thermal stability of polyhydroxyalkanoates

In this study, we examined the thermal decomposition of polyhydroxyalkanoates (PHAs) such as the homopolymer poly(3‐hydroxybutyrate) and the copolymer poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate). They are biodegradable polymers that can replace plastics produced from nonrenewable resources, such as polypropylene. The biopolymers we analyzed were commercial PHAs [obtained by means of pure cultures, with hydroxyvalerate (HV) contents of 0 and 10.4 mol %] and biopolymers produced in our laboratories (by means of an enriched activated sludge at two different organic loads, 8.5 and 20 gCOD/L, with a HV content of 20 mol %). To process these biopolymers, it is important to know their thermal stability. For this reason, thermal degradation in air by means of dynamic thermogravimetry (TG) was carried out. The TG data were adjusted to the nth‐order general analytical equation to evaluate the best order of the reaction, the temperatures of the onset and end of thermal decomposition, and the kinetic parameters. The latter were also calculated by means of other integral and differential methods and compared to those obtained by the general analytical solution. Finally, the influence of the preparation method (pure and mixed cultures and HV content within the biopolymer) on thermal stability was analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2111–2121, 2006     

Novel Bio-Based Materials and Applications in Antimicrobial Food Packaging: Recent Advances and Future Trends

Food microbial contamination not only poses the problems of food insecurity and economic loss, but also contributes to food waste, which is another global environmental problem. Therefore, effective packaging is a compelling obstacle for shielding food items from outside contaminants and maintaining its quality. Traditionally, food is packaged with plastic that is rarely recyclable, negatively impacting the environment. Bio-based materials have attracted widespread attention for food packaging applications since they are biodegradable, renewable, and have a low carbon footprint. They provide a great opportunity to reduce the extensive use of fossil fuels and develop food packaging materials with good properties, addressing environmental problems and contributing significantly to sustainable development. Presently, the developments in food chemistry, technology, and biotechnology have allowed us to fine-tune new methodologies useful for addressing major safety and environmental concerns regarding packaging materials. This review presents a comprehensive overview of the development and potential for application of new bio-based materials from different sources in antimicrobial food packaging, including carbohydrate (polysaccharide)-based materials, protein-based materials, lipid-based materials, antibacterial agents, and bio-based composites, which can solve the issues of both environmental impact and prevent foodborne pathogens and spoilage microorganisms. In addition, future trends are discussed, as well as the antimicrobial compounds incorporated in packaging materials such as nanoparticles (NPs), nanofillers (NFs), and bio-nanocomposites.     

Recent developments in biopolymers

Society has been reaping the benefits of industrial polymers for a long time. Polymers have entered every market in a very influential manner, from the packaging industry to the construction business. The very properties that made polymers commercially viable are posing great environmental problems for our future generations. Also, the starting material for most of the commercial polymers is crude oil. Thus, environmental issues coupled with decreasing crude oil reserves have forced the polymer industry to find new sources. These problems having been taken into consideration, biopolymers have emerged as a promising field. This paper takes into consideration the sources of renewable materials, such as starch, lignocellulosic biomass, vegetable oils, proteins, etc.; the synthesis of polymers such as polylactic acid and monomers such as furfural, ethane, propanediol, etc., from renewable materials; and the recent developments in this field. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

Treatments of protein for biopolymer production in view of processability and physical properties: A review

The development of bio‐based polymers from proteins has gained attention for their large availability and renewable and biodegradable nature. However, protein‐based plastics have limited commercial applications because of several drawbacks, such as poor processability, brittleness, moisture sensitivity, and inferior mechanical and thermal properties. Extensive studies have been conducted to solve or ameliorate these issues by pretreatment or modification of proteins or protein‐derived biopolymers before or during wet processing or dry processing at elevated temperatures. This review provides an overview of research efforts conducted in the area of physical and chemical treatment of proteins to achieve better processability, mechanical properties, and other physical performance based on a literature review in this subject. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43351.     

An overview of luminescent bio‐based composites

The development of inorganic/organic composite materials represents a fast‐growing interdisciplinary area in materials science and engineering. In this topic, a key idea is the production of composites comprising biopolymers and functional inorganic phases that could replace conventional materials in several high‐technology applications. Following this concept, the use of different polymers from renewable sources, such as cellulose, starch, alginate, and chitosan, have gained great relevance because of their renewable nature, potential biocompatibility, and biodegradability, as well as specific physicochemical properties. The combination of these biopolymers with different fillers (including inorganic nanoparticles (NPs), clusters, or ions) allows the design of innovative bio‐based materials with specific and/or improved properties, namely, optical, mechanical, and barrier properties, luminescence, and biological properties (as antimicrobial activity and biocompatibility). This review will focus on the most important synthetic approaches, properties, and applications of luminescent bio‐based composites obtained by combining different biopolymers and fillers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41169.     

Preparation and application of chitin and its derivatives: a review

Chitin the second most abundant polysaccharide is synthesized by an enormous number of living organisms including fungi and insects. These biopolymers have found many applications in different areas such as: packaging material, membrane for removal of metal ions, dyes and pigments in waste water engineering; anti-cholesterol, fat binding, preservative and food additive in food industry; seed and fertilizer coating, controlled agrochemical release in agriculture; surface treatment, photographic paper in pulp and paper industry; moisturizer, body creams and lotions in cosmetics and toiletries. It has also found wide applications in biomedical such as tissue engineering, drug delivery, wound dressing, scaffolds, cancer diagnosis, etc. The majority of these versatile applications are coming of its non-toxicity, biocompatibility and biodegradability. Chitin is also easily processed as gel, membrane, and nanofiber. This review emphasizes an extensive bibliography of recent basic and applied research and investigations on the aspects of this interesting biopolymer including the recovery, preparation, modification and application of chitin and its derivatives and related compounds. A new class of biocompatible and biodegradable chitin-based polyurethane (PU) elastomer was also introduced and reviewed in this study and it was found that by incorporation of chitin into the PU elastomer backbone, biocompatibility and degradation rate of the final elastomer improved. PUs are one of the synthetic biocompatible polymers with excellent physical and mechanical properties. Combination of this polymer with chitin resulted to a new tailor-made biocompatible and biodegradable polymer with improved properties. These polymers have potential applications in various applications including biomedical.     

Multifunctionality of foamed poly(lactid acid) and its composites with nanofillers

Polymers derived from renewable resources focus increasingly on an interest of research institutes and industry. Replacement of traditional materials by biodegradable polymers brings about the fossil resources savings and helps solving problems related to the plastic packaging waste. Polylactide (PLA) is the most important biodegradable polyester of good mechanical properties, high transparency, and good processability. However, PLA is still more expensive than conventional plastics, moreover its biodegradation rate is moderate. Recent innovations open new fields of PLA application by means of novel nanocomposites and processing technology that provide new properties. In this article, polymeric materials of various functionalities have been presented, in particular PLA‐based functional nanocomposites (with increased barrier properties, electroconductive, or thermosensitive materials) of PLA and cellular PLA . POLYM. COMPOS., 36:1647–1652, 2015. © 2014 Society of Plastics Engineers     

Copolymers of polyhydroxyalkanoates and polyethylene glycols: recent advancements with biological and medical significance

Copolymers of polyhydroxyalkanoates (PHAs ) and polyethylene glycols (PEGs ) have gained high significance for biological and medical applications within the past few years. PHAs are natural biopolymers (hydrophobic biopolyesters), which can be produced microbially and also synthetically, and PEGs are biocompatible hydrophilic polyethers, which are frequently used in medicine to enhance the effect of bioactive compounds. Both polymers can be conjugated with a variety of other polymers, and in particular the conjugation with each other affords hydrophobic ? hydrophilic PHA‐PEG copolymers with high significance as biomaterials. This paper describes selected recent developments in this field with a focus on synthetic approaches and the suitability of the resulting copolymers for applications in drug delivery and tissue engineering. © 2016 Society of Chemical Industry     

RETRACTED ARTICLE: Towards understanding polyhydroxyalkanoates and their use

It is fact that Polymers and their products have changed the face of the world in all the field of the technology. They are the future of the coming up generation of the research of the world. But this is also fact that these synthetic non biodegradable polymers have created a tough situation for the living being for a healthy life. Polyhydroxyalkanoates are polyesters produced by bacteria as intracellular storage materials in response to a variety of nutritional and environmental conditions, such as nitrogen limitation Polyhydroxyalkanoates (PHAs) are gaining increasing attention in the biodegradable polymer market due to their promising properties such as high biodegradability in different environments, not just in composting plants, and processing versatility. Indeed among biopolymers, these biogenic polyesters represent a potential sustainable replacement for fossil fuel-based thermoplastics. Most commercially available PHAs are obtained with pure microbial cultures grown on renewable feedstocks (i.e.glucose) under sterile conditions but recent research studies focus on the use of wastes as growth media.PHA can be extracted from the bacteria cell and then formulated and processed by extrusion for production of rigid and flexible plastic suitable not just for the most assessed medical applications but also considered for applications including packaging, moulded goods, paper coatings, non-oven fabrics, adhesives, films and performance additives. The present paper reviews the PHAs, their main properties, processing aspects, commercially available ones, as well as limitations and related improvements being researched,with specific focus on potential applications of PHAs in packaging.     

Biobased adhesives,gums, emulsions,and binders: current trends and future prospects

Biopolymers derived from renewable resources are an emerging class of advanced materials that offer many useful properties for a wide range of food and nonfood applications. Current state of the art in research and development of renewable polymers as adhesives, gums, binders, and emulsions is the subject of this review. Much of the focus will be on major biopolymers such as starch, proteins, lignin, oils, and their derivatives found in both natural and modified forms, but other biopolymers of promising commercial interest will also be included where warranted. Polymers produced in nature are remarkably diverse in their chemistry, thermomechanical properties, rheology, plasticity, and chemical reactivity. In particular, their capacity to undergo a wide array of chemical modifications yields materials with tailored properties suitable for use as adhesives, gums, coatings, emulsions, and binders. Many such materials are now widely used in commercial products like building materials, lubricants, sealants, coatings, bonding aids, pharmaceuticals, paper, glues, flocculants, processed and frozen foods, as well as tissue engineering and bone repair products. This review provides a general overview of biobased polymers highlighting their source, availability, properties, and usage in industrial products along with the future prospects, challenges, and opportunities they offer.     

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     

Biopolymers as Carriers for Nasal Drug Delivery

Biopolymers are the most abundant raw materials that can be obtained from natural sources including bacteria, fungi, plants and even humans. The biopolymers are easily available, non-toxic, biodegradable and Generally Regarded as Safe (GRAS). These natural polymers can play an important role in the formulation of drug delivery systems by influencing the release, residence time and permeation of the therapeutic agent. The present review gives an insight into the important biopolymers and their properties in the effective delivery of the therapeutic agents systemically as well as targeting the brain via the intranasal route.     

A review on degradation mechanisms of polylactic acid: Hydrolytic,photodegradative, microbial,and enzymatic degradation

Recently, thoughtful disagreements between scientists concerning environmental issues including the use of renewable materials have enhanced universal awareness of the use of biodegradable materials. Polylactic acid (PLA) is one of the most promising biodegradable materials for commercially replacing nondegradable materials such as polyethylene terephthalate and polystyrene. The main advantages of PLA production over the conventional plastic materials is PLA can be produced from renewable resources such as corn or other carbohydrate sources. Besides, PLA provides adequate energy saving by consuming CO₂ during production. Thus, we aim to highlight recent research involving the investigation of properties of PLA, its applications and the four types of potential PLA degradation mechanisms. In the first part of the article, a brief discussion of the problems surrounding use of conventional plastic is provided and examples of biodegradable polymers currently used are provided. Next, properties of PLA, and (Poly[L-lactide]), (Poly[D-lactide]) (PDLA) and (Poly[DL-lactide]) and application of PLA in various industries such as in packaging, transportation, agriculture and the biomedical, textile and electronic industry are described. Behaviors of PLA subjected to hydrolytic, photodegradative, microbial and enzymatic degradation mechanisms are discussed in detail in the latter portion of the article.     

聚羟基烷酸酯——一种应用广泛的生物降解聚合物

综述了聚羟基烷酸酯(PHAs)在工业、农业、医药等不同领域中的应用状况。工业应用包括生产各类工业品、包装物和处理工业废水等;医药应用包括制作各类医疗器件和进行药物缓释释放等;农业应用包括生产农用薄膜、进行农药缓释和作物固氮等。此外,通过将PHAs与碳纳米管、蒙脱土等材料复合,可制成具有特殊应用性能的纳米复合材料。     

The nitrogen fertiliser value and other agronomic benefits of industrial biowastes

An estimated 7 million t of industrial biowastes are landspread annually in the UK. Quantitative research into their fertiliser replacement value and agronomic benefit is required to increase their use in agriculture, recycle valuable nutrients, and contribute to the reduction of biodegradable waste sent to landfill. A programme of systematically designed field experiments was established to quantify the agronomic value of a range of industrial biowastes, including examples from the vegetable, meat and dairy processing industries and digested biowastes from industrial aerobic and anaerobic digestion plants. Dewatered anaerobically digested biosolids (DMAD) was included as a reference material. Yield and N offtake responses of perennial ryegrass, at five rates of application of each biowaste type were used to calculate the N equivalency relative to mineral N fertiliser. Liquid thermophilic aerobic digestate (LTAD) of food waste was an effective source of available N, with an N equivalency of 59–76 %. Liquid mesophilic anaerobic co-digestates of livestock slurry and food waste (LcoMAD) had N equivalencies between 68 and 85 %. Vegetable processing waste and brewing waste (yeast) had N equivalency values of 45 and 89 %, respectively. Regarding other nutrient elements, the biowastes were generally a source of P, vegetable wastes were significant sources of K, and DMAD and the dewatered anaerobically digested organic fraction of municipal solid waste (DMADMSW) were effective sources of S. Certain waste types were not effective sources of N for crop growth (e.g. potato processing wastes, kieselguhr) and require further investigation at greater rates of application to determine their agronomic benefit.     

Influence of α′‐/α‐crystal polymorphism on properties of poly(l‐lactic acid)

Poly(l ‐lactic acid) (PLLA) is a biodegradable and biocompatible thermoplastic polyester produced from renewable sources, widely used for biomedical devices, in food packaging and in agriculture. It is a semicrystalline polymer, and as such its properties are strongly affected by the developed semicrystalline morphology. As a function of the crystallization temperature, PLLA can form different crystal modifications, namely α′‐crystals below about 120 °C and α‐crystals at higher temperatures. The α′ modification is therefore of special importance as it may be the preferred polymorph developing at processing‐relevant conditions. It is a metastable modification which typically transforms into the more stable α‐crystals on annealing at elevated temperature. The structure, kinetics of formation and thermodynamics of α′‐ and α‐crystals of PLLA are reviewed in this contribution, together with the effect of α′‐/α‐crystal polymorphism on the properties of PLLA. © 2018 Society of Chemical Industry     

Production of polyhydroxyalkanoates: the future green materials of choice

Polyhydroxyalkanoates (PHAs) have recently been the focus of attention as a biodegradable and biocompatible substitute for conventional non degradable plastics. The cost of large‐scale production of these polymers has inhibited its widespread use. Thus, economical, large‐scale production of PHAs is currently being studied intensively. Various bacterial strains, either wild‐type or recombinant have been utilized with a wide spectrum of utilizable carbon sources. New fermentation strategies have been developed for the efficient production of PHAs at high concentration and productivity. With the current advances, PHAs can now be produced to a concentration of 80 g L^?1 with productivities greater than 4 g PHA L^?1 h^?1. These advances will further lower the production cost of PHAs and allow this family of polymers to become a leading biodegradable polymer in the near future. This review describes the properties of PHAs, their uses, the various attempts towards the production of PHAs, focusing on the utilization of cheap substrates and the development of different fermentation strategies for the production of these polymers, an essential step forward towards their widespread use. Copyright © 2010 Society of Chemical Industry     

Optimizing the mechanical and physical properties of thermoplastic starch via tuning the molecular microstructure through co‐plasticization by sorbitol and glycerol

Nowadays, environmental hazards caused by plastic wastes are a major concern in academia and industry. Utilization of biodegradable polymers derived from renewable sources for replacing common petroleum‐based plastics is a potential solution for reducing the problem. In this regard, starch has become one of the most promising alternatives to non‐biodegradable polymers for depleting plastic waste thanks to its low expense, abundance, renewability and biodegradability. However, the main drawbacks of starch are its poor processability, weak mechanical properties and severe hydrophilicity. In this work, thermoplastic starch (TPS) samples have been prepared using glycerol and sorbitol as co‐plasticizers in a laboratory co‐rotating twin screw extruder. Based on the mechanical test results, glycerol caused higher elongation to break but had lower tensile strength and elastic modulus compared to sorbitol plasticized starch. Fourier transform infrared spectroscopy and DSC results indicated that the hydrogen bond interaction between starch chains and plasticizers could be improved by replacing glycerol by sorbitol, which resulted in higher resistance against retrogradation proved by XRD results. TGA illustrated that the higher the sorbitol to glycerol ratio was, the more stable was the TPS. Using a proper amount of plasticizers (42 wt% total plasticizer, sorbitol to glycerol ratio 2:1) led to the preparation of a TPS sample with optimized properties including enhanced mechanical properties, high thermal stability, strong hydrogen bond formation and high resistance against retrogradation. © 2017 Society of Chemical Industry