Novel active packaging based on films of chitosan and chitosan/quinoa protein printed with chitosan-tripolyphosphate-thymol nanoparticles via thermal ink-jet printing

Polysaccharide-based antibacterial coating technologies

To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. STATEMENT OF SIGNIFICANCE: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.

Polysaccharide-based nanoassemblies: From synthesis methodologies and industrial applications to future prospects

Polysaccharides, due to their remarkable features, have gained significant prominence in the sustainable production of nanoparticles (NPs). High market demand and minimal production cost, compared to the chemically synthesised NPs, demonstrate a drive towards polysaccharide-based nanoparticles (PSNPs) benign to environment. Various approaches are used for the synthesis of PSNPs including cross-linking, polyelectrolyte complexation, and self-assembly. PSNPs have the potential to replace a wide diversity of chemical-based agents within the food, health, medical and pharmacy sectors. Nevertheless, the considerable challenges associated with optimising the characteristics of PSNPs to meet specific targeting applications are of utmost importance. This review provides a detailed compilation of recent accomplishments in the synthesis of PSNPs, the fundamental principles and critical factors that govern their rational fabrication, as well as various characterisation techniques. Noteworthy, the multiple use of PSNPs in different disciplines such as biomedical, cosmetics agrochemicals, energy storage, water detoxification, and food-related realms, is accounted in detail. Insights into the toxicological impacts of the PSNPs and their possible risks to human health are addressed, and efforts made in terms of PSNPs development and optimising strategies that allow for enhanced delivery are highlighted. Finally, limitations, potential drawbacks, market diffusion, economic viability and future possibilities for PSNPs to achieve widespread commercial use are also discussed.

Application of chitosan nanoparticles in quality and preservation of postharvest fruits and vegetables: A review

Chitosan is an interesting alternative material for packaging development due to its biodegradability. However, its poor mechanical properties and low permeability limit its actual applications. Chitosan nanoparticles (CHNPs) have emerged as a suitable solution to overcome these intrinsic limitations. In this review, all studies regarding the use of CHNPs to extend the shelf life and improve the quality of postharvest products are covered. The characteristics of CHNPs and their combinations with essential oils and metals, along with their effects on postharvest products, are compared and discussed throughout the manuscript. CHNPs enhanced postharvest antioxidant capacity, extended shelf life, increased nutritional quality, and promoted tolerance to chilling stress. Additionally, the CHNPs reduced the incidence of postharvest phytopathogens. In most instances, smaller CHNPs (<150 nm) conferred higher benefits than larger ones (>150 nm). This was likely a result of the greater plant tissue penetrability and surface area of the smaller CHNPs. The CHNPs were either applied after preparing an emulsion or incorporated into a film, with the latter often exhibiting greater antioxidant and antimicrobial activities. CHNPs were used to encapsulate essential oils, which could be released over time and may enhance the antioxidant and antimicrobial properties of the CHNPs. Even though most applications were performed after harvest, preharvest application had longer lasting effects.

Nano Edible Coatings and Films Combined with Zinc Oxide and Pomegranate Peel Active Phenol Compounds Has Been to Extend the Shelf Life of Minimally Processed Pomegranates

Edible coating and film from chitosan and incorporating it with the action of ZnONPs on active phenol compounds from extracts of pomegranate peel (PPE) The physical and chemical properties of edible films composed of zinc oxide ZnONPs and active phenol compounds extracted from pomegranate peel (PPE) were investigated. Adding ZnONPs with active phenol compounds from extracted pomegranate peel(PPE) to chitosan films can provide safe edible films, decrease microbial growth and consequently prolong the shelf life of pomegranates, as well as improve the physiochemical stability of the pomegranate. The substances used in this experiment were film with a (A) extract of pomegranate peels (PPE), 5% (0.1%), (B)ZnONPs 1% (0.02%), (C) ZnONPs 2% (0.04%), (D) ZnONPs 3% (0.06%), (E) ZnONPs 1%/PPE1% (0.02%), (F) ZnONPs 2%/PPE2% (0.04%), (G) ZnONPs 3%/PPE3% (0.06%) wt% of chitosan on quality attributes and prolonging the shelf life of pomegranates were stored in plastic containers at 2 °C and 90-95% relative humidity for 20 days. The treatments of (G) ZnONPs 3%/PPE3% (0.06%) loaded on chitosan as well as chitosan and (D) ZnONPs 3% (0.06%) reduced the weight loss, had excellent microbial count until 20 days of storage, and recorded the lowest microbial count and mould & yeast colonies. Other chemical properties, such as total soluble solids content, acidity, anthocyanin content, firmness, and ascorbic acid, were investigated. Results indicated that ZnONPs 3%/PPE3% (0.06%) loaded on chitosan or ZnONPs 3% (0.06%) are the best treatments for preserving pomegranate arils. It was found that the best measurements were that the film-forming nan emulsion solutions decreased by E% 110 nm and B% 134 nm. Nano followed treatment, F% 188.7 nm, compared to nano edible films, which were A 0% 1312 nm.

Microstructure, rheological and water mobility behaviour of plant-based protein isolates (pea and quinoa) and locust bean gum mixtures

This work reports the impact of locust bean gum (LBG) in the continuous phase of plant-based proteins, i.e. quinoa protein (QPI) and pea protein isolates (PPI). Experimental measurements such as confocal microscopy, rheological analysis and water mobility via nuclear magnetic resonance (nmr) spin-spin relaxation time (T2) were carried out. The influence of LBG on the rheological properties of QPI and PPI is consistent with an exchange-based nmr interpretation of T2 for biopolymer and water. Addition of LBG increased the viscoelastic properties (storage and loss modulus) and shear viscosities of the mixtures. LBG interacted with both plant proteins, resulting in the formation of more dense protein networks and protein coacervates. A stronger interaction between the PPI and LBG was observed, resulting in higher shear viscosities with lower water mobility as compared to QPI:LBG formulations. Results indicated that the interaction between the protein and polysaccharide played a significant role in the microstructure, its rheological properties and consequently water mobility.

From Classical to Advanced Use of Polymers in Food and Beverage Applications

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer's applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.

Plant protein-based nanocomposite films: A review on the used nanomaterials, characteristics, and food packaging applications

Consumer demands to utilize environmentally friendly packaging have led researchers to develop packaging materials from naturally derived resources. In recent years, plant protein-based films as a replacement for synthetic plastics have attracted the attention of the global food packaging industry due to their biodegradability and unique properties. Biopolymer-based films need a filler to show improved packaging properties. One of the latest strategies introduced to food packaging technology is the production of nanocomposite films which are multiphase materials containing a filler with at least one dimension less than 100 nm. This review provides the recent findings on plant-based protein films as biodegradable materials that can be combined with nanoparticles that are applicable to food packaging. Moreover, it investigates the characterization of nanocomposite plant-based protein films/edible coatings. It also briefly describes the application of plant-based protein nanocomposite films/coating on fruits/vegetables, meat and seafood products, and some other foods. The results indicate that the functional performance, barrier, mechanical, optical, thermal and antimicrobial properties of plant protein-based materials can be extended by incorporating nanomaterials. Recent reports provide a better understanding of how incorporating nanomaterials into plant protein-based biopolymers leads to an increase in the shelf life of food products during storage time.

Properties and Applications of Intelligent Packaging Indicators for Food Spoilage

Food packaging plays a vital role in the food supply chain by acting as an additional layer to protect against food contamination, but the main function of traditional conventional packaging is only to isolate food from the outside environment, and cannot provide related information about food spoilage. Intelligent packaging can feel, inspect, and record external or internal changes in food products to provide further information about food quality. Importantly, intelligent packaging indicators will account for a significant proportion of the food industry’s production, with promising application potential. In this review, we mainly summarize and review the upcoming progress in the classification, preparation, and application of food packaging indicators. Equally, the feasibility of 3D printing in the preparation of intelligent food packaging indicators is also discussed in detail, as well as the limitations and future directions of smart food packaging. Taken together, the information supported in this paper provides new insights into monitoring food spoilage and food quality.

A spotlight on analytical prospects in food allergens: From emerging allergens and novel foods to bioplastics and plant-based sustainable food contact materials

The present review throws a spotlight on new and emerging food safety concerns in view of a well-established food allergen risk arising from global socio-economic changes, international trade, circular economy, environmental sustainability, and upcycling. Food culture globalization needs harmonization of regulations, technical specifications, and reference materials towards mutually recognised results. In parallel, routine laboratories require high-throughput reliable analytical strategies, even in-situ testing devices, to test both food products and food contact surfaces for residual allergens. Finally, the currently neglected safety issues associated to possible allergen exposure due to the newly proposed bio- and plant-based sustainable food contact materials require an in-depth investigation.

Chitosan and Whey Protein Bio-Inks for 3D and 4D Printing Applications with Particular Focus on Food Industry

The application of chitosan (CS) and whey protein (WP) alone or in combination in 3D/4D printing has been well considered in previous studies. Although several excellent reviews on additive manufacturing discussed the properties and biomedical applications of CS and WP, there is a lack of a systemic review about CS and WP bio-inks for 3D/4D printing applications. Easily modified bio-ink with optimal printability is a key for additive manufacturing. CS, WP, and WP-CS complex hydrogel possess great potential in making bio-ink that can be broadly used for future 3D/4D printing, because CS is a functional polysaccharide with good biodegradability, biocompatibility, non-immunogenicity, and non-carcinogenicity, while CS-WP complex hydrogel has better printability and drug-delivery effectivity than WP hydrogel. The review summarizes the current advances of bio-ink preparation employing CS and/or WP to satisfy the requirements of 3D/4D printing and post-treatment of materials. The applications of CS/WP bio-ink mainly focus on 3D food printing with a few applications in cosmetics. The review also highlights the trends of CS/WP bio-inks as potential candidates in 4D printing. Some promising strategies for developing novel bio-inks based on CS and/or WP are introduced, aiming to provide new insights into the value-added development and commercial CS and WP utilization.

Advances in biopolymeric active films incorporated with emulsified lipophilic compounds: a review

The attention towards active films has increased due to consumer demand for high-quality foods without chemical additives. Active biopolymer-based films have shown great potential for active films by impacting food safety, acting as the carriers of various natural antioxidant and antimicrobial compounds, and decreasing environmental pollution from petrol-derived packaging materials. However, there is a wide range of challenges concerning the different characteristics of biopolymers and plasticizers, often hygroscopic/hydrophilic, compared to numerous lipophilic bioactive compounds. Therefore, recent studies have focused on applying oil-in-water emulsion-based systems to enhance the lipophilic bioactive compounds' dispersibility into the film matrix, improving their performance. It is worth emphasizing that resulting complex systems give rise to new challenges such as (i) dispersion technology of the bioactive compounds with minimum adverse effects on its bioactivities, (ii) interactions between different components of the active films, giving rise to new physicochemical properties, and (iii) the change of the diffusion properties of bioactive compounds into the active films, resulting in different release properties. These challenges are profound and critically discussed in this review, as well as the encapsulation techniques employed in preparing emulsions loaded with lipophilic bioactive compounds for the active film development. An outlook of future directions in the research, development, and application of these active films are given.

Potentials of polysaccharides, lipids and proteins in biodegradable food packaging applications

Bio-based packaging materials are gaining importance due to their biodegradability, sustainability and environmental friendliness. To control the food quality and improve the food safety standards, proteins polysaccharide and lipid-based packaging films are enriched with bioactive and functional substances. However, poor permeability and mechanical characteristics are the challenging areas in their commercialization. Scientists and researchers are using a combination of techniques i.e. hydrogels, crosslinking, etc. to improve the intermolecular forces between different components of the film formulation to counter these challenges More recently, biodegradable packaging materials, sometimes edible, are also used for the delivery of functional ingredients which reveals their potential for drug delivery to counter the nutrient deficiency problems. This study highlights the potentials of bio-based materials i.e. proteins, polysaccharides, lipids, etc. to develop biodegradable packaging materials. It also explores the additives used to improve the physicochemical and mechanical properties of biodegradable packaging materials. Furthermore, it highlights the novel trends in biodegradable packaging from a food safety and quality point of view.

Protein-Based Films and Coatings for Food Industry Applications

Food packaging is an area of interest not just for food producers or food marketing, but also for consumers who are more and more aware about the fact that food packaging has a great impact on food product quality and on the environment. The most used materials for the packaging of food are plastic, glass, metal, and paper. Still, over time edible films have become widely used for a variety of different products and different food categories such as meat products, vegetables, or dairy products. For example, proteins are excellent materials used for obtaining edible or non-edible coatings and films. The scope of this review is to overview the literature on protein utilization in food packages and edible packages, their functionalization, antioxidant, antimicrobial and antifungal activities, and economic perspectives. Different vegetable (corn, soy, mung bean, pea, grass pea, wild and Pasankalla quinoa, bitter vetch) and animal (whey, casein, keratin, collagen, gelatin, surimi, egg white) protein sources are discussed. Mechanical properties, thickness, moisture content, water vapor permeability, sensorial properties, and suitability for the environment also have a significant impact on protein-based packages utilization.

Preparation of aerogel beads and microspheres based on chitosan and cellulose for drug delivery: A review

Spherical aerogels are not easily broken during use and are easier to transport and store which can be used as templates for drug delivery. This review summarizes the possible approaches for the preparation of aerogel beads and microspheres based on chitosan and cellulose, an overview to the methods of manufacturing droplets is presented, afterwards, the transition mechanisms from sol to a spherical gel are reviewed in detail followed by different drying processes to obtain spherical aerogels with porous structures. Additionally, a specific focus is given to aerogel beads and microspheres to be regarded as drug delivery carriers. Furthermore, a core/shell architecture of aerogel beads and microspheres for controlled drug release is described and subjected to inspire readers to create novel drug release system. Finally, the conclusions and outlooks of aerogel beads and microspheres for drug delivery are summarized.

Rheological and Antimicrobial Properties of Chitosan and Quinoa Protein Filmogenic Suspensions with Thyme and Rosemary Essential Oils

Food packaging faces the negative impact of synthetic materials on the environment, and edible coatings offer one alternative from filmogenic suspensions (FS). In this work, an active edible FS based on chitosan (C) and quinoa protein (QP) cross-linked with transglutaminase was produced. Thyme (T) and rosemary (R) essential oils (EOs) were incorporated as antimicrobial agents. Particle size, Z potential, and rheological parameters were evaluated. The antimicrobial activity against Micrococcus luteus (NCIB 8166) and Salmonella sp. (Lignieres 1900) was monitored using atomic force microscopy and image analysis. Results indicate that EOs incorporation into C:QP suspensions did not affect the Z potential, ranging from -46.69 ± 3.19 mV to -46.21 ± 3.83 mV. However, the polydispersity index increased from 0.51 ± 0.07 to 0.80 ± 0.04 in suspensions with EO. The minimum inhibitory concentration of active suspensions against Salmonella sp. was 0.5% (v/v) for thyme and 1% (v/v) for rosemary. Entropy and fractal dimension of the images were used to confirm the antimicrobial effect of EOs, which modified the surface roughness.

Antimicrobial and Antibiofilm Capacity of Chitosan Nanoparticles against Wild Type Strain of Pseudomonas sp. Isolated from Milk of Cows Diagnosed with Bovine Mastitis

Bovine mastitis (BM) is the most prevalent bacterial infection in the livestock sector, affecting the dairy industry greatly. The prevention and treatment of this disease is mainly made via antibiotics, but the increasing antimicrobial resistance of pathogens has affected the efficiency of conventional drugs. Pseudomonas sp. is one of the pathogens involved in this infection. The therapeutic rate of cure for this environmental mastitis-causing pathogen is practically zero, regardless of treatment. Biofilm formation has been one of the main virulence mechanisms of Pseudomonas hence presenting resistance to antibiotic therapy. We have manufactured chitosan nanoparticles (NQo) with tripolyphosphate (TPP) using ionotropic gelation. These NQo were confronted against a Pseudomonas sp. strain isolated from milk samples of cows diagnosed with BM, to evaluate their antimicrobial and antibiofilm capacity. The NQo showed great antibacterial effect in the minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC) and disk diffusion assays. Using sub lethal concentrations, NQo were tested for inhibition of biofilm formation. The results show that the nanoparticles exhibited biofilm inhibition and were capable of eradicate pre-existing mature biofilm. These findings indicate that the NQo could act as a potential alternative to antibiotic treatment of BM.

Aqueous Processed Biopolymer Interfaces for Single-Cell Microarrays

Single-cell microarrays are emerging tools to unravel intrinsic diversity within complex cell populations, opening up new approaches for the in-depth understanding of highly relevant diseases. However, most of the current methods for their fabrication are based on cumbersome patterning approaches, employing organic solvents and/or expensive materials. Here, we demonstrate an unprecedented green-chemistry strategy to produce single-cell capture biochips onto glass surfaces by all-aqueous inkjet printing. At first, a chitosan film is easily inkjet printed and immobilized onto hydroxyl-rich glass surfaces by electrostatic immobilization. In turn, poly(ethylene glycol) diglycidyl ether is grafted on the chitosan film to expose reactive epoxy groups and induce antifouling properties. Subsequently, microscale collagen spots are printed onto the above surface to define the attachment area for single adherent human cancer cells harvesting with high yield. The reported inkjet printing approach enables one to modulate the collagen area available for cell attachment in order to control the number of captured cells per spot, from single-cells up to double- and multiple-cell arrays. Proof-of-principle of the approach includes pharmacological treatment of single-cells by the model drug doxorubicin. The herein presented strategy for single-cell array fabrication can constitute a first step toward an innovative and environmentally friendly generation of aqueous-based inkjet-printed cellular devices.

Encapsulation Systems for Antimicrobial Food Packaging Components: An Update

Antimicrobially active packaging has emerged as an effective technology to reduce microbial growth in food products increasing both their shelf-life and microbial safety for the consumer while maintaining their quality and sensorial properties. In the last years, a great effort has been made to develop more efficient, long-lasting and eco-friendly antimicrobial materials by improving the performance of the incorporated antimicrobial substances. With this purpose, more effective antimicrobial compounds of natural origin such as bacteriocins, bacteriophages and essential oils have been preferred over synthetic ones and new encapsulation strategies such as emulsions, core-shell nanofibres, cyclodextrins and liposomes among others, have been applied in order to protect these antimicrobials from degradation or volatilization while trying to enable a more controlled release and sustained antimicrobial action. On that account, this article provides an overview of the types of antimicrobials agents used and the most recent trends on the strategies used to encapsulate the antimicrobial agents for their stable inclusion in the packaging materials. Moreover, a thorough discussion regarding the benefits of each encapsulation technology as well as their application in food products is presented.

Effect of Transglutaminase Cross-Linking in Protein Isolates from a Mixture of Two Quinoa Varieties with Chitosan on the Physicochemical Properties of Edible Films

The growing demand for minimally processed foods with a long shelf life and environmentally friendly materials has forced industry to develop new technologies for food preservation and handling. The use of edible films has emerged as an alternative solution to this problem, and mixtures of carbohydrates and proteins, may be formulated to improve their properties. The objective of this work was to evaluate the effect of protein cross-linking with transglutaminase (TG) of two varieties of quinoa protein isolate (Chenopodium quinoa) [Willd (QW), and Pasankalla (QP)] on the physicochemical and barrier properties of edible films based on chitosan (CT)-quinoa protein. The evaluated properties were water vapor permeability (WVP), solubility, adsorption, roughness determined by atomic force microscopy, and the interactions among the main film components determined by Raman spectroscopy. The results indicated that TG interacted with lysine of QW and QP. CT:QW (1:5, w/w) showed the lowest solubility (14.02 ± 2.17% w/w). WVP varied with the composition of the mixture. The WVP of CT:quinoa protein ranged from 2.85 to 9.95 × 10−11 g cm Pa−1 cm−2 s−1 without TG, whereas adding TG reduced this range to 2.42–4.69 × 10−11 g cm Pa−1 cm−2 s−1. The addition of TG to CT:QP (1:10, w/w) reduced the film surface roughness from 8.0 ± 0.5 nm to 4.4 ± 0.3 nm. According to the sorption isotherm, the addition of TG to CT-QW films improved their stability [monolayer (Xm) = 0.13 ± 0.02 %]. Films with a higher amount of cross-linking showed the highest improvement in the evaluated physical properties, but interactions among proteins that were catalyzed by TG depended on the protein source and profile.

Emerging Chitosan-Based Films for Food Packaging Applications

Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrier films, and sensing films have achieved great developments. This article comprehensively reviews recent advances in the preparation and application of engineered chitosan-based films in food packaging fields.

Antimicrobial Polymers in the Nano-World

Infections are one of the main concerns of our era due to antibiotic-resistant infections and the increasing costs in the health-care sector. Within this context, antimicrobial polymers present a great alternative to combat these problems since their mechanisms of action differ from those of antibiotics. Therefore, the microorganisms' resistance to these polymeric materials is avoided. Antimicrobial polymers are not only applied in the health-care sector, they are also used in many other areas. This review presents different strategies that combine nanoscience and nanotechnology in the polymer world to combat contaminations from bacteria, fungi or algae. It focuses on the most relevant areas of application of these materials, viz. health, food, agriculture, and textiles.