Comparative study of processing methods for starch/gelatin films

Benefits of Incorporating Lignin into Starch-Based Films: A Brief Review

Polysaccharides are an excellent renewable source for developing food-packing materials. It is expected that these packages can be an efficient barrier against oxygen; can reduce lipid peroxidation, and can retain the natural aroma of a food commodity. Starch has tremendous potential to be explored in the preparation of food packaging; however, due to their high hydrophilic nature, packaging films produced from starch possess poor protective moisture barriers and low mechanical properties. This scenario limits their applications, especially in humid conditions. In contrast, lignin's highly complex aromatic hetero-polymer network of phenylpropane units is known to play a filler role in polysaccharide films. Moreover, lignin can limit the biodegradability of polysaccharides films by a physical barrier, mainly, and by non-productive bindings. The main interactions affecting lignin non-productive bindings are hydrophobic interactions, electrostatic interactions, and hydrogen-bonding interactions, which are dependent on the total phenolic -OH and -COOH content in its chemical structure. In this review, the use of lignin as a reinforcement to improve the biodegradability of starch-based films in wet environments is presented. Moreover, the characteristics of the used lignins, the mechanisms of molecular interaction among these materials, and the sensitive physicochemical parameters for biodegradability detection are related.

Evaluation of Gel Coating Performance in Extending the Shelf Life of Egg: The Role of Surface Area and Initial Weight

This work investigated the impact of chicken egg size, including surface area and initial weight, on the effectiveness of cassava starch-based gel coating during storage at room temperature. The quality of a total of 540 fresh eggs in four different sizes (S, M, L and XL) was evaluated over a 4-week storage period at 25 ± 1 °C (60-65% RH). In this research, images from a scanning electron microscope revealed that the coatings maintained their integrity across all egg sizes, effectively covering pores and cracks throughout storage. The application of gel coating reduced weight loss and preserved the Haugh unit and yolk index, extending freshness by 1-2 weeks compared with uncoated eggs at 25 °C. The results indicated that the performance of the coating varied with egg size. Statistical analysis revealed that the surface area and initial weight of the egg significantly impacted the effectiveness of the coating in preserving quality (p < 0.001). Eggs with larger surface areas exhibited a reduced protective effect of the coating, resulting in higher weight loss and lower retention of Haugh unit and yolk index compared with the coated eggs with smaller surface areas. The coating application was more effective in preserving the Haugh unit of eggs with higher initial weights. Overall, the surface area and the initial weight of the egg should be considered as key factors to ensure optimal coating performance.

Investigation of the Structure-Forming Potential of Protein Components in the Reformulation of the Composition of Edible Films

To optimize the functional properties of edible films or coatings, mixtures of several ingredients are used, including food processing by-products. In this way, pectin from fruit pomace, whey proteins from whey as a by-product of rennet cheese production, and gelatin from by-products of the processing of slaughtered animals can be obtained. The aim and scope of the investigation were to verify the hypothesis of the research, which assumes that the addition of beef broth to edible gelatin films will affect the gelation processes of the tested film-forming solutions and will allow for the modification of the edible properties of the films obtained based on these solutions. Measurements were carried out to determine the visual parameters, mechanical strengths, surface and cross-sectional structures, FTIR spectra, thermal degradation rates, and hydrophilicities of the prepared gelatin films. The water content, water vapor permeability, and course of water vapor sorption isotherms of the films were also examined, as well as the course of the gelation process for film-forming solutions. The addition of broth to film-forming solutions was found to increase their opacity and color saturation, especially for the ones that were yellow. The films with the addition of broth were more uneven on the surface and more resistant to stretching, and in the case of the selected types of gelatins, they also formed a more stable gel. The broth increased the hydrophilicity and permeability of the water vapor and reduced the water content of the films. The addition of broth enables the practical use of edible films, but it is necessary to modify some features.

Gelatin and gelatin/starch-based films modified with sorbitol for wound healing

Gelatin-based films modified with sorbitol were produced from gelatin solution or gelatin/starch blends using a simple and low-cost solvent casting method, and subsequently, their physicochemical, mechanical, and biocompatibility properties were characterized. This work focused on developing and optimizing a biopolymeric blend to improve the pure biopolymers' properties for potential biomedical applications such as wound dressing. The films were characterized in terms of morphology and transparency, mechanical, moisture and swelling properties, thermal stability, and degradation potential. Moreover, hemocompatibility, as well as cytocompatibility of prepared films, were examined. The addition of sorbitol contributed to improving mechanical properties, swelling reduction, and increasing biostability over time. The cytocompatibility of obtained films was confirmed in vitro with two different human cell lines, fibroblastic and osteoblastic, and a more favorable cellular response was received for fibroblasts. Further, in hemocompatibility studies, it was found that all films may be classified as non-hemolytic as they did not have a negative effect on the human erythrocytes. The obtained results indicate the great potential of the gelatin/starch blends modified with sorbitol as regenerative biomaterials intended for wound healing applications.

Starch-gelatin blend films: A promising approach for high-performance degradable food packaging

Packaging plays a vital role in safeguarding food from environmental factors and contamination. However, the overuse and improper disposal of non-biodegradable plastic packaging materials have led to environmental concerns and health risks. To address these challenges, the development of degradable food packaging films is crucial. Biodegradable polymers, including natural biopolymers like starch (ST) and gelatin (GE), have emerged as promising alternatives to traditional plastics. This review focuses on the utilization of ST-GE blends as key components in composite films for food packaging applications. We discuss the limitations of pure ST-GE films and explore methods to enhance their properties through the addition of plasticizers, cross-linkers, and nanoparticles. The blending of ST-GE, facilitated by their good miscibility and cross-linking potential, is highlighted as a means to improve film performance. The review also examines the impact of various additives on the properties of ST-GE blend films and summarizes their application in food preservation. By providing a comprehensive overview of ST-GE hybrid systems, this study aims to contribute to the advancement of sustainable and effective food packaging solutions.

Optimizing the Functional Properties of Starch-Based Biodegradable Films

A definitive screening design was used in order to evaluate the effects of starch, glycerol and montmorillonite (MMT) concentrations, as well as the drying temperature, drying tray type and starch species, on packaging film's functional properties. Optimization showed that in order to obtain films with the minimum possible thickness, the maximum elongation at break, the maximum tensile strength, as well as reduced water vapor permeability and low opacity, a combination of factors should be used as follows: 5.5% wt starch concentration, 30% wt glycerol concentration on a dry starch basis, 10.5% wt MMT concentration on a dry starch basis, 45 °C drying temperature, chickpea as the starch species and plexiglass as the drying tray type. Based on these results, starch films were prepared, and fresh minced meat was stored in them for 3 days. It was shown that the incorporation of MMT at 10.5% wt on a dry starch basis in the packaging films led to a decreased mesophilic and psychrotrophic bacteria growth factor compared to commercial packaging. When assessed for their biodegradability, the starch films disintegrated after 10 days of thermophilic incubation under simulated composting conditions. Finally, to prove their handling capability during industrial production, the starch films were rewound in a paper cylinder using an industrial-scale rewinding machine.

Influence of acetylation and chemical interaction on edible film properties and different processing methods for food application

This study developed sweet potato starch (SPS) based edible films and investigated several methods (acetylation, amidated pectin (AP), and CaCl₂ use) to improve the edibility and different processing methods (casting and extruding) to package food possible in commercial use. Starch acetylation was conducted with up to 8 mL of acetic acid (A8) and improved the stretchability and solubility of the film. The AP addition [∼30 wt% (P3)] enhanced the film strength, further increasing solubility. CaCl₂ addition [∼150 mg/g of AP (C3)] also positively influenced the film solubility and water barrier properties of the films. The SPS-A8P3C3 film showed 3.41 times higher solubility than the native SPS film. Both casted and extruded SPS-A8P3C3 films drastically dissolved in high-temperature water. When applied to oil packaging, two films could delay the lipid oxidation of the packaged samples. These results demonstrate the usability of edible packaging and extruded film for commercial use.

Biopolymers as green-based food packaging materials: A focus on modified and unmodified starch-based films

The ideal food packaging materials are recyclable, biodegradable, and compostable. Starch from plant sources, such as tubers, legumes, cereals, and agro-industrial plant residues, is considered one of the most suitable biopolymers for producing biodegradable films due to its natural abundance and low cost. The chemical modification of starch makes it possible to produce films with better technological properties by changing the functional groups into starch. Using biopolymers extracted from agro-industrial waste can add value to a raw material that would otherwise be discarded. The recent COVID-19 pandemic has driven a rise in demand for single-use plastics, intensifying pressure on this already out-of-control issue. This review provides an overview of biopolymers, with a particular focus on starch, to develop sustainable materials for food packaging. This study summarizes the methods and provides a potential approach to starch modification for improving the mechanical and barrier properties of starch-based films. This review also updates some trends pointed out by the food packaging sector in the last years, considering the impacts of the COVID-19 pandemic. Perspectives to achieve more sustainable food packaging toward a more circular economy are drawn.

Selected Biopolymers' Processing and Their Applications: A Review

Petroleum-based polymers are used in a multitude of products in the commercial world, but their high degree of contamination and non-biodegradability make them unattractive. The development and use of polymers derived from nature offer a solution to achieve an environmentally friendly and green alternative and reduce waste derived from plastics. This review focuses on showing an overview of the most widespread production methods for the main biopolymers. The parameters affecting the development of the technique, the most suitable biopolymers, and the main applications are included. The most studied biopolymers are those derived from polysaccharides and proteins. These biopolymers are subjected to production methods that improve their properties and modify their chemical structure. Process factors such as temperature, humidity, solvents used, or processing time must be considered. Among the most studied production techniques are solvent casting, coating, electrospinning, 3D printing, compression molding, and graft copolymerization. After undergoing these production techniques, biopolymers are applied in many fields such as biomedicine, pharmaceuticals, food packaging, scaffold engineering, and others.

Production and Characterization of Gelatin Biomaterials Based on Agave Microfibers and Bentonite as Reinforcements

The objective of this work was to obtain biomaterials as gelatin films or biofilms produced by casting, reinforced with a microfiber (MF) from Agave angustifolia Haw bagasse and bentonite (BN) nanoparticles and evaluate the effect of such reinforcements at different concentrations. Agave microfibers were obtained by a non-abrasive chemical method. Three formulations based on gelatin with glycerol were reinforced with microfiber, bentonite and both materials with 1.5, 3.5 and 5.5% w/w solids content. Physicochemical properties were determined using SEM and FTIR, thickness, soluble matter and moisture. The XRD, barrier, mechanical and thermal properties were measured. The films’ micrographs showed agglomerations on the surface. Interactions between its functional groups were found. The solubility increased when the MF concentration increased. The thickness of the films was between 60 and 110 μm. The crystallinity ranged from 23 to 86%. The films with both MF and BN and 3.5% w/w solids had the lowest barrier properties, while the film with 5.5% w/w solids showed the highest mechanical properties, being thermally resistant. Overall, Agave microfibers together with bentonite were able to improve some of the films’ properties, but optimized mixing conditions had to be used to achieve good particle dispersion within the gelatin matrix to improve its final properties. Such materials might have the potential to be used as food packaging.

Synthesis, Characterization, and Optimization Studies of Starch/Chicken Gelatin Composites for Food-Packaging Applications

The indiscriminate use of plastic in food packaging contributes significantly to environmental pollution, promoting the search for more eco-friendly alternatives for the food industry. This work studied five formulations (T1–T5) of biodegradable cassava starch/gelatin films. The results showed the presence of the starch/gelatin functional groups by FT-IR spectroscopy. Differential scanning calorimetry (DSC) showed a thermal reinforcement after increasing the amount of gelatin in the formulations, which increased the crystallization temperature (Tc) from 190 °C for the starch-only film (T1) to 206 °C for the film with 50/50 starch/gelatin (T3). It also exhibited a homogeneous surface morphology, as evidenced by scanning electron microscopy (SEM). However, an excess of gelatin showed low compatibility with starch in the 25/75 starch/gelatin film (T4), evidenced by the low Tc definition and very rough and fractured surface morphology. Increasing gelatin ratio also significantly increased the strain (from 2.9 ± 0.5% for T1 to 285.1 ± 10.0% for T5) while decreasing the tensile strength (from 14.6 ± 0.5 MPa for T1 to 1.5 ± 0.3 MPa for T5). Water vapor permeability (WVP) increased, and water solubility (WS) also decreased with gelatin mass rising in the composites. On the other hand, opacity did not vary significantly due to the films’ cassava starch and gelatin ratio. Finally, optimizing the mechanical and water barrier properties resulted in a mass ratio of 53/47 cassava starch/gelatin as the most appropriate for their application in food packaging, indicating their usefulness in the food-packaging industry.

Edible Coatings to Enhance Shelf life of Fruits and Vegetables -A Mini Review

Abstract:

Recently, edible coatings or films have gained enormous importance in fruits and vegetables preservation. This review summarises edible coatings, the classification of coating materials, formulation procedures, and the benefits of active edible coating. Studies reported that edible coating or films from natural resources benefit the consumer as well as the environment. In general, edible coatings or films are a combination of polysaccharides, proteins, lipids, and plasticizers, used to enhance the functional properties and the general quality parameters of fruits and vegetables, such as texture, colour, acidity, total soluble solids, thus preventing their browning and oxidation. Casting (wet process) and extrusion (dry process) are two prominent methods used to fabricate edible thin films. General techniques for applying edible coatings are dipping, spraying, coating, panning, using a fluidized bed, and film wrapping. Active edible coatings or films are developed with herbal extracts to improve the functional properties, i.e., antioxidant and antimicrobial. Therefore, based on the literature review, future research exploration will focus on underutilized edible natural resources, along with some natural edible plasticizers used to improve the postharvest quality of fruits and vegetables without affecting their nutritional, organoleptic, and sensory attributes. The primary objective of the present review was to summarize the different types of edible coating with an infusion of herbal extracts and their application on fruits and vegetables.

The control of fungi and mycotoxins by food active packaging: a review

Conventionally used petrochemical-based plastics are poorly degradable and cause severe environmental pollution. Alternatively, biopolymers (e.g., polysaccharides, proteins, lipids, and their blends) are biodegradable and environment-friendly, and thus their use in packaging technologies has been on the rise. Spoilage of food by mycotoxigenic fungi poses a severe threat to human and animal health. Hence, because of the adverse effects of synthetic preservatives, active packaging as an effective technique for controlling and decontaminating fungi and related mycotoxins has attracted considerable interest. The current review aims to provide an overview of the prevention of fungi and mycotoxins through active packaging. The impact of different additives on the antifungal and anti-mycotoxigenic functionality of packaging incorporating active films/coatings is also investigated. In addition, active packaging applications to control and decontaminate common fungi and mycotoxins in bakery products, cereal grains, fruits, nuts, and dairy products are also introduced. The results of recent studies have confirmed that biopolymer films and coatings incorporating antimicrobial agents provide great potential for controlling common fungi and mycotoxins and enhancing food quality and safety.

Characterization and Parametric Study on Mechanical Properties Enhancement in Biodegradable Chitosan-Reinforced Starch-Based Bioplastic Film

Bioplastic has been perceived as a promising candidate to replace petroleum-based plastics due to its environment-friendly and biodegradable characteristics. This study presents the chitosan reinforced starch-based bioplastic film prepared by the solution casting and evaporation method. The effects of processing parameters, i.e., starch concentration, glycerol loading, process temperature and chitosan loading on mechanical properties were examined. Optimum tensile strength of 5.19 MPa and elongation at break of 44.6% were obtained under the combined reaction conditions of 5 wt.% starch concentration, 40 wt.% glycerol loading, 20 wt.% chitosan loading and at a process temperature of 70 °C. From the artificial neural network (ANN) modeling, the coefficient of determination (R²) for tensile strength and elongation at break were found to be 0.9955 and 0.9859, respectively, which proved the model had good fit with the experimental data. Interaction and miscibility between starch and chitosan were proven through the peaks shifting to a lower wavenumber in FTIR and a reduction of crystallinity in XRD. TGA results suggested the chitosan-reinforced starch-based bioplastic possessed reasonable thermal stability under 290 °C. Enhancement in water resistance of chitosan-incorporated starch-based bioplastic film was evidenced with a water uptake of 251% as compared to a 302% registered by the pure starch-based bioplastic film. In addition, the fact that the chitosan-reinforced starch-based bioplastic film degraded to 52.1% of its initial weight after 28 days suggests it is a more sustainable alternative than the petroleum-based plastics.

Assessment of Biodegradation and Eco-Toxic Properties of Novel Starch and Gelatine Blend Bioplastics

To combat the release of petroleum-derived plastics into the environment the European Commission has adopted the EU plastics strategy, which aims for a complete ban on single-use plastics by 2030. Environmentally friendly and sustainable packaging like bioplastic is being up taken at significant levels by companies and consumers. In this study, the environmental impact of novel gelatine–starch blend bioplastics is investigated. The assessments included ecotoxicology with different species that can be found in marine and soil environments to simulate natural conditions. Microalgae, plant, and nematode species were chosen as these are representative of their habitats and are known for their sensitivity to pollutants. Degradation rates of these novel bioplastics were assessed as well as microbiome analysis of the soil before and after bioplastic degradation. The main findings of this study are that (i) the bioplastic generated can be fully biodegraded in soil environments at moderate conditions (20 °C) leaving no physical traces; (ii) bioplastic did not exhibit significantly adverse effects on any organisms assessed in this study; (iii) microbiome analysis of the soil after biodegradation showed a decrease in alpha diversity and a significant increase of Actinobacteria and Firmicutes phyla, which were dominative in the soil.

Marine Biopolymers: Applications in Food Packaging

Marine sources are gaining popularity and attention as novel materials for manufacturing biopolymers such as proteins and polysaccharides. Due to their biocompatibility, biodegradability, and non-toxicity features, these biopolymers have been claimed to be beneficial in the development of food packaging materials. Several studies have thoroughly researched the extraction, isolation, and latent use of marine biopolymers in the fabrication of environmentally acceptable packaging. Thus, a review was designed to provide an overview of (a) the chemical composition, unique properties, and extraction methods of marine biopolymers; (b) the application of marine biopolymers in film and coating development for improved shelf-life of packaged foods; (c) production flaws and proposed solutions for better isolation of marine biopolymers; (d) methods of preparation of edible films and coatings from marine biopolymers; and (e) safety aspects. According to our review, these biopolymers would make a significant component of a biodegradable food packaging system, reducing the amount of plastic packaging used and resulting in considerable environmental and economic benefits.

Interactions of the molecular assembly of polysaccharide-protein systems as encapsulation materials. A review

Studying the interactions of biopolymers like polysaccharides and proteins is quite important mainly due to the wide number of applications such as the stabilization and encapsulation of active compounds in complex systems. Complexation takes place when materials like proteins and polysaccharides are blended to promote the entrapment of active compounds. The interaction forces between the charged groups in the polymeric chains allow the miscibility of the components in the complex system. Understanding the interactions taking place between the polymers as well as between the wall material and the active compound is important when designing delivery systems. However, some features of the biopolymers like structure, functional groups, or electrical charge as well as extrinsic parameters like pH or ratios might affect the structure and the performance of the complex system when used in encapsulation applications. This work summarizes the recent progress of the polysaccharide/protein complexes for encapsulation and the influence of the pH on the structural modifications during the complexation process.

Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

There is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

Characterization and Cell Viability of Probiotic/Prebiotics Film Based on Duck Feet Gelatin: A Novel Poultry Gelatin as a Suitable Matrix for Probiotics

The probiotic viability, physicochemical, mechanical, barrier, and microstructure properties of synbiotic edible films (SEFs) based on duck feet gelatin (DFG) were evaluated. Four synbiotic systems were obtained by mixing four types of prebiotics, namely, dextrin, polydextrose, gum Arabic, and sago starch, with DFG to immobilize of probiotic (Lactobacillus casei ATCC). The ability of DFG to create a suitable matrix to increase probiotic viability was compared with those of other commercial gelatins in a preliminary evaluation. The DFG showed proper probiotic viability compared with other gelatins. The addition of prebiotics reduced the transparency of SEFs and increased color differentiation, uniformity, and complete coverage of probiotic cells. The estimated shelf-life of surviving bacteria in the SEFs stored at 4 and 25 °C showed that gum arabic showed the best performance and enhanced the viability of L. casei by 42% and 45%, respectively. Dextrin, polydextrose, and sago starch enhanced the viability of L. casei at 4 and 25 °C by 26% and 35%, 26% and 5%, and 20% and 5%, respectively. The prebiotics improved the physicochemical, mechanical, and barrier properties of all SEFs, except polydextrose film. The viability of L. casei can be increased with the proper selection of gelatin and prebiotics.

Comparison of Mechanical and Physicochemical Characteristics of Potato Starch and Gelatine Blend Bioplastics Made with Gelatines from Different Sources

Environmentally friendly packaging is becoming more popular as the number of companies implementing more sustainable solutions continues to increase, and consumers become more aware and choose more environmentally friendly options. However, not all environmentally friendly packaging meets all desirable properties, as some are only partially made of renewable raw materials or degrade over a long period of time. Bioplastics constructed from blends of gelatine and starch are solely made from renewable raw materials. Combined with relatively short degradation times, these materials have the potential to replace currently used, non-biodegradable film and single-use plastics. However, despite these advantages, further research is required to identify the best combination of raw materials, selectively and collectively, and to then optimise the appropriate physicochemical properties of the resultant bioplastics. In this study, gelatine from different sources (piscine, porcine, bovine) combined with potato starch was used to generate home-compostable bioplastics. These bioplastics were assessed in terms of water solubility, water content, opacity, surface roughness, and key mechanical properties such as tensile strength. Significant differences were found, particularly for piscine gelatine blends. It was concluded that piscine gelatine is a promising protein with highly relevant properties for the bioplastics industry.

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.

Incorporation of Poly(Itaconic Acid) with Quaternized Thiazole Groups on Gelatin-Based Films for Antimicrobial-Active Food Packaging

Poly(itaconic acid) (PIA) was synthesized via conventional radical polymerization. Then, functionalization of PIA was carried out by an esterification reaction with the heterocyclic groups of 1,3-thiazole and posterior quaternization by N-alkylation reaction with iodomethane. The modifications were confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR), as well as ζ-potential measurements. Their antimicrobial activity was tested against different Gram-negative and Gram-positive bacteria. After characterization, the resulting polymers were incorporated into gelatin with oxidized starch and glycerol as film adjuvants, and dopamine as crosslinking agent, to develop antimicrobial-active films. The addition of quaternized polymers not only improved the mechanical properties of gelatin formulations, but also decreased the solution absorption capacity during the swelling process. However, the incorporation of synthesized polymers increased the deformation at break values and the water vapor permeability of films. The antioxidant capacity of films was confirmed by radical scavenging ability and, additionally, those films exhibited antimicrobial activity. Therefore, these films can be considered as good candidates for active packaging, ensuring a constant concentration of the active compound on the surface of the food, increasing products' shelf-life and reducing the environmental impact generated by plastics of petrochemical origin.

Methods of Incorporating Plant-Derived Bioactive Compounds into Films Made with Agro-Based Polymers for Application as Food Packaging: A Brief Review

Plastic, usually derived from non-renewable sources, is among the most used materials in food packaging. Despite its barrier properties, plastic packaging has a recycling rate below the ideal and its accumulation in the environment leads to environmental issues. One of the solutions approached to minimize this impact is the development of food packaging materials made from polymers from renewable sources that, in addition to being biodegradable, can also be edible. Different biopolymers from agricultural renewable sources such as gelatin, whey protein, starch, chitosan, alginate and pectin, among other, have been analyzed for the development of biodegradable films. Moreover, these films can serve as vehicles for transporting bioactive compounds, extending their applicability as bioactive, edible, compostable and biodegradable films. Biopolymer films incorporated with plant-derived bioactive compounds have become an interesting area of research. The interaction between environment-friendly biopolymers and bioactive compounds improves functionality. In addition to interfering with thermal, mechanical and barrier properties of films, depending on the properties of the bioactive compounds, new characteristics are attributed to films, such as antimicrobial and antioxidant properties, color and innovative flavors. This review compiles information on agro-based biopolymers and plant-derived bioactive compounds used in the production of bioactive films. Particular emphasis has been given to the methods used for incorporating bioactive compounds from plant-derived into films and their influence on the functional properties of biopolymer films. Some limitations to be overcome for future advances are also briefly summarized. This review will benefit future prospects for exploring innovative methods of incorporating plant-derived bioactive compounds into films made from agricultural polymers.

Improving nisin production by encapsulated Lactococcus lactis with starch/carboxymethyl cellulose edible films

In this study, Lactococcus lactis was embedded in a film of corn starch (NS) and carboxymethyl cellulose (CMC) prepared using a casting method. At a CMC:NS ratio of 5:5, the composite film had the best comprehensive properties. Scanning electron microscopy images clearly showed that L. lactis was effectively embedded. The film with 1.5 % L. lactis showed the best performance and the lowest water vapor transmission rate (5.54 × 10^-11 g/m s Pa. In addition, the edible film retained a viable count of 5.64 log CFU/g of L. lactis when stored at 4 °C for 30 days. The composite film with 1.5 % L. lactis showed the highest release of nisin (3.35 mg/mL) and good antibacterial activity against Staphylococcus aureus (53.53 %) after 8 days. Therefore, this edible film is a viable alternative antimicrobial strategy for the active packaging of foods containing low moisture content.

Film formation and deposition methods of edible coating on food products: A review

The greatest challenge encountered by the food manufacturer is the loss of quality of food products during storage, which eventually adds to the waste. Edible packaging is known as a potential alternative to protecting food quality and improving shelf life by delaying microbial spoilage and providing moisture and gas barrier properties. Developments in edible packaging and technology have shown promising results in enhancing the shelf life of food products. In 2016, the edible packaging market was valued at $697 million and by 2023 is expected to hit $1097 million growing at a compound annual growth rate (CGAR) of 6.81% from 2017 to 2023 at global level. In global edible packaging markets specific industries including MonoSol LLC, Tate & Lyle Plc, WikiCell Designs Inc., JRF Technology LLC, Safetraces, Inc., BluWrap, Skipping Rocks Lab, Tipa Corp., Watson Inc., and Devro plc have played a key role. Edible packaging can be applied in two forms: (i) edible coating applied directly on the food product or (ii) preformed film wrapped around the food product. The aim of this study is to review different methods of film formation and edible coating depositions. Edible films can be produced using two methods, wet (casting) and dry (extrusion) processes; and methods such as dipping, spraying, fluidized-bed, and panning are used for deposition of edible coatings on the surface of food product. Casting and dipping methods for film formation and coating deposition, respectively, are easy to use and are preferred methods on a lab scale; whereas extrusion and spraying are preferred methods for film formation and coating deposition, respectively, on a commercial scale. This work can help researchers and industries to select an efficient and cost-effective method for the development of edible film/coating for specific application. Further study and evaluation of practical applications of methods of edible packaging should be carried out within the main purpose of keeping food safe with acceptable quality for extended period of time.

Essential Oils-Loaded Electrospun Biopolymers: A Future Perspective for Active Food Packaging

The growth of global food demand combined with the increased appeal to access different foods from every corner of the globe is forcing the food industry to look for alternative technologies to increase the shelf life. Essential oils (EOs) as naturally occurring functional ingredients have shown great prospects in active food packaging. EOs can inhibit the growth of superficial food pathogens, modify nutritious values without affecting the sensory qualities of food, and prolong the shelf life when used in food packaging as an active ingredient. Since 2016, various reports have demonstrated that combinations of electrospun fibers and encapsulated EOs could offer promising results when used as food packaging. Such electrospun platforms have encapsulated either pure EOs or their complexation with other antibacterial agents to prolong the shelf life of food products through sustained release of active ingredients. This paper presents a comprehensive review of the essential oil-loaded electrospun fibers that have been applied as active food packaging material.

Optimization of chicken skin gelatin film production with different glycerol concentrations by response surface methodology (RSM) approach

This study investigated the optimization of chicken skin gelatin film production using different concentrations of glycerol as plasticizer, specifically for use as biodegradable food packaging. Response surface methodology (RSM) was used to optimize the production of gelatin films by following a central composite design (CCD) for two quantitative modulators-(A) gelatin at 1.0, 2.5 and 4.0 g; and (B) glycerol at 0, 0.75, 1.50 g-with outcome metrics to predict tensile strength (TS), elongation at break (EAB) and water vapor permeability (WVP). Potentially optimized conditions were experimentally validated to confirm the model's suggestions of 4.0 g for gelatin and 1.5 g for glycerol. Experimental results yielded a TS of 3.81 N/mm, which was higher than the RSM predicted value of 3.09 N/mm (p < 0.05). Both EAB and WVP experimental results were slightly lower than predicted values (3.04 vs. 3.14%) (p < 0.05); and (1.27 × 10-9 vs. 1.31 × 10-9 kPa) (p < 0.05), respectively. Overall, experimental results agreed with the model's predicted values. Hence, this study demonstrates that optimized conditions for the production of chicken skin gelatin films are affected by glycerol concentration and gelatin quantity. Results also suggest that chicken skin gelatin-glycerol film blends have excellent potential for the production of biodegradable food packaging with improved properties.

Starch-gelatin film as an alternative to the use of plastics in agriculture: a review

BACKGROUND

The technological advances in agriculture, driven by the increased demand for food attributed to population growth, have led to the search for technologies that allow greater control over the variables that interfere in crop yield. Several techniques stand out for optimizing yield capacity, including cultivation in a protected environment, mulching and low tunneling. To expand the use of these techniques, synthetic petroleum-based polymers are employed due to their low cost, easy processing, and lightness. However, they take a long time to degrade, and, since they are discarded at the end of each cycle of cultivation, end up accumulating in the environment causing irreversible damage.

RESULTS

The use of biodegradable films, made of starch and/or a protein source such as gelatin, has been studied as a promising alternative. Both stand out because of their film-forming ability, and because they come from abundant sources and are biodegradable.

CONCLUSION

This study aimed to review the current findings on starch and gelatin films that can be used as alternatives to conventional plastics in agricultural crops. © 2019 Society of Chemical Industry.

Physical Properties of Composite Films from Tilapia Skin Collagen with Pachyrhizus Starch and Rambutan Peel Phenolics

Different composite films composed of tilapia skin collagen (TSC) with Pachyrhizus starch (PS) or rambutan peel phenolics (RPP) were prepared, and the physical properties of these films were determined. The effects of PS and RPP on TSC films were investigated, and our results indicated that PS and RPP could improve the physical properties of TSC films. Opacity and film thickness showed an enhanced trend with increasing PS and RPP contents in TSC films, whereas solubility in water, elongation-at-break (EAB), and water vapor permeability (WVP) showed declining trends. TSC film with 10% PS and 0.5% RPP had the highest tensile strength, and the tensile strength dropped drastically when the content of PS and RPP increased. The light transmittances of the films could decrease with the incorporation of PS and RPP. Differential scanning calorimetry (DSC) demonstrated that the addition of PS and RPP improved the thermal stability of TSC films. In addition, X-ray diffraction indicated that the crystallinity of the films decreased and the amorphous structure of the films tended to become more complex with the addition of PS and RPP. As shown by fourier transform infrared spectroscopy (FTIR) analysis, PS and RPP can strongly interact with TSC, resulting in a modification of its structure. Scanning electron microscope (SEM) analysis showed that there was a good compatibility between TSC, PS, and RPP. The results indicated that TSC film incorporated with 10% PS and 0.5% RPP was an effective method for improve the physical properties of the film. TSC–PS–RPP composite films can be used not only in biomedical applications, but also as active food packaging materials.

Bioactive Edible Films Based on Arrowroot Starch Incorporated with Cranberry Powder: Microstructure, Thermal Properties, Ascorbic Acid Content and Sensory Analysis

The growing global awareness about environmental preservation has stimulated the search for alternatives to replace conventional plastics made from fossil sources. One of the advantages is using polymers from renewable sources, such as starch and gelatin, which, in addition to being biodegradable, may also be edible. The incorporation of cranberry into a polymeric matrix can transfer bioactive composite films, colour and flavour to the film, which are characteristic of this fruit, expanding its application to fruit stripes or colourful coatings for specific foods. In this context, the aim of this work was to evaluate the influence of the incorporation of 0, 5, 15, 25, 35, 45 and 55% (solids mass/biopolymer mass) cranberry powder on the microstructure, thermal properties, ascorbic acid content and sensory analysis of gelatin and arrowroot starch films obtained by casting. Scanning electron microscopy (SEM) images showed that the incorporation of cranberry made the film surface rough and irregular. All films presented an X-ray diffraction pattern typical of a semicrystalline material. The glass transition temperature (T_g) decreased when increasing the concentration of cranberry in films. All films with cranberry presented high ascorbic acid content and were well accepted by the tasters when sensory analysis was performed.

Application of Edible and Biodegradable Starch-Based Films in Food Packaging: A Systematic Review and Meta-Analysis

In recent years, natural polymers such as starch have been widely considered as alternatives to plastics derived from petroleum derivatives in the production of packaging films. Currently, modified starches with new functional features are available that can be used in the production of the above mentioned films. The aim at this study is a systematic review and meta-analysis of application of edible and biodegradable starch-based films in food packaging. At first all of the studies related to our title by using some keywords (edible and biodegradable starch-based films and food packaging) searched for English databases; Google, Google scholar, PubMed, Embase, CINAHL, PsycInfo, SCOPUS and ISI web of Science during the 2010 to 2018 was run consisting a predefined inclusion and exclusion factors. Inclusion and exclusion criteria were: papers related to edible and biodegradable starch-based films and food packaging, papers were English, types of papers were original and all the papers were free full text. As a result, related to inclusion and exclusion criteria papers were found and analyses. Data were collected based on study characteristics, edible and biodegradable starch-based films, food packaging. In the initial search, 589 articles were found that after reviewing the titles and abstract articles and removing repetitive and non-related, 33 possible related articles were examined. Of these, 24 articles were omitted from the abstract because of lack of access to the original article and lack of sufficient information. Finally, 13 papers were included in the study. Due to novel research on the application of bio-degradable biofilms in the packaging industry of food, starch is one of the most promising and promising sources. Different needs in the food packaging industry for bio-films have led to the diverse sources of starch being studied, because each source has its own specific characteristics. The properties of films obtained from starch indicated the rigidity and reduced flexibility of the films. To prevent this and the corresponding effects on the film, other polymers can be used as additive compounds. Extending the use of starch structure techniques and the use of this material in combination with other materials to reduce the inherent weaknesses of this natural polymer has led to its further development in various industries, especially packaged industries. Starch is a proper substitute for polymers extracted from oil derivatives. In order to improve the characteristics of the produced films, a high number of compounds can be added to the matrix, and various variations can be applied during the processing. Optimizing conditions will produce transparent, non-odorous, non-flavored, and color-free films with improved mechanical, optical and deterrent features.

Optimization of corn starch acetylation and succinylation using the extrusion process

Starch chemical modification can be used in order to obtain modified starches (MS) with low affinity to water. Acetylated and succinylated starches whose applications as food ingredient depend upon their degree of substitution (DS) may be produced by esterifying starch through the extrusion process (EP). The Food and Drug Administration recommends a DS of 0.2 and 0.05 for acetylated and succinylated starches, respectively. The objective of this study was to find mathematical models to obtain the optimum values of DS, Water absorption Index (WAI) and Water Solubility Index (WSI) for MS with safe-for-food-use DS and low affinity to water, modifying the starches by acetylation and succinylation using EP. The process variables were Barrel Temperature (BT, 80-160 °C), Screw Speed (SS, 100-200 rpm) and Reactant Concentration (RC, Acetylation, 0-13% and Succinylation, 0-3%). The best conditions to obtain acetylated starches were RC = 7.88%, BT = 80 °C and SS = 100 rpm, presenting values of DS = 0.2, WAI = 7.67 g/g and WSI = 6.15%. On the other hand, the optimum conditions to obtain succinylated starches were RC = 1.12%, BT = 80 °C and SS = 126 rpm, obtaining values of DS = 0.05, WAI = 3.40 g/g and WSI = 7.92%. These results showed that it is possible to obtain acetylated and succinylated MS with safe-for-food-use levels of DS and with low affinity to water, using EP.

Corn and Rice Starch-Based Bio-Plastics as Alternative Packaging Materials

Due to the negative environmental impacts of synthetic plastics, the development of biodegradable plastics for both industrial and commercial applications is essential today. Researchers have developed various starch-based composites for different applications. The present work investigates the corn and rice starch-based bioplastics for packaging applications. Various samples of bioplastics are produced, with different compositions of corn and rice starch, glycerol, citric acid, and gelatin. The tensile properties were improved after adding rice starch. However, water absorption and water solubility were reduced. On the basis of these results, the best sample was analyzed for thickness testing, biodegradability properties, SEM, hydrophilicity, thermogravimetric analysis, and sealing properties of bioplastic. The results show the suitability of rice and corn-based thermoplastic starch for packaging applications.