Development of Burdock Root Inulin/Chitosan Blend Films Containing Oregano and Thyme Essential Oils

Harnessing the power of Arctium lappa root: a review of its pharmacological properties and therapeutic applications

Arctium lappa, widely recognized as burdock, is a perennial plant that is employed in the realm of traditional Chinese medicine for a wide range of medicinal applications. The herb is rich in bioactive metabolites with therapeutic potential, encompassing polyphenolic antioxidants in its leaves, and flavonoids and fructo-oligosaccharides in its underground parts. Nutraceuticals originating from botanical sources such as Arctium lappa provide supplementary health advantages alongside their nutritional content and have demonstrated effectiveness in the prevention and management of specific ailments. The utilization of Arctium lappa root extract has exhibited encouraging outcomes in addressing hepatotoxicity induced by cadmium, lead, chromium, and acetaminophen, ameliorating liver damage and oxidative stress. Additionally, the root extract displays properties such as antidiabetic, hypolipidemic, aphrodisiac, anti-rheumatic, anti-Alzheimer, and various other pharmacological actions.

Animal derived biopolymers for food packaging applications: A review

It is essential to use environment-friendly, non-toxic, biodegradable and sustainable materials for various applications. Biopolymers are derived from renewable sources like plants, microorganisms, and agricultural wastes. Unlike conventional polymers, biopolymer has a lower carbon footprint and contributes less to greenhouse gas emission. All biopolymers are biodegradable, meaning natural processes can break them down into harmless products such as water and biomass. This property is of utmost importance for various sustainable applications. This review discusses different classifications of biopolymers based on origin, including plant-based, animal-based and micro-organism-based biopolymers. The review also discusses the desirable properties that are required in materials for their use as packaging material. It also discusses the different processes used in modifying the biopolymer to improve its properties. Finally, this review shows the recent developments taking place in using specifically animal origin-based biopolymer and its use in packaging material. It was observed that animal-origin-based biopolymers, although they possess unique properties however, are less explored than plant-origin biopolymers. The animal-origin-based biopolymers covered in this review are chitosan, gelatin, collagen, keratin, casein, whey, hyaluronic acid and silk fibroin. This review will help in renewing research interest in animal-origin biopolymers. In summary, biopolymer offers a sustainable and environment-friendly alternative to conventional polymers. Their versatility, biocompatibility will help create a more sustainable future.

Development and characterization of edible films based on flaxseed gum incorporated with Piper betle extract

There has been a shift from use of petroleum-based plastics, causing serious environmental pollution, towards innovative and biodegradable edible packaging. The present study documents the development of composite edible films based on the flaxseed gum (FSG) modified by the incorporation of betel leaf extract (BLE). The films were assessed for physicochemical, mechanical, morphological, thermal, antimicrobial and structural characteristics. Scanning electron microscopy images indicated that the roughness decreased with an increase in BLE concentration. The water vapor permeability of the FSG-BLE films ranged from 4.68 to 1.59 × 10-9 g s- 1 m- 2 Pa- 1, lower than that of the control sample (6.77 × 10-9 g s- 1 m- 2 Pa- 1). The BLE4 (containing 10 % BLE) films had the highest tensile strength of 32.46 MPa compared to the control sample (21.23 MPa). Similarly, EAB and seal strength of the films incorporated with BLE were ameliorated. X-ray diffraction pattern and FTIR illustrated the shift of amorphous to crystalline behavior and a significant interaction among the BLE and FSG functional groups. Furthermore, the thermal stability of the treated films was not affected significantly however, they showed improved antimicrobial activity with the highest diameter of inhibition zone in the BLE4 sample. This study concluded that the FSG-BLE composite films (BLE4 in particular) can be considered as novel packaging material for food conservation coupled with a potential to enhance the shelf life of perishable food products.

Advanced Biomaterials for Food Edible Coatings

The aim of this Special Issue is to highlight recent investigations on different biopolymers obtained from renewable sources for use as edible coatings [...].

PVA/Inulin-Based Sustainable Films Reinforced with Pickering Emulsion of Niaouli Essential Oil for Potential Wound Healing Applications

In this study, sustainable water-based films were produced via the solvent-casting method. Petroleum-free-based polyvinyl alcohol (PVA) and carbohydrate-based inulin (INL) were used as matrices. Vegetable-waste pumpkin powder was used in the study because of its sustainability and antibacterial properties. Pickering emulsions were prepared using β-cyclodextrin. The influence of the different ratios of the β-cyclodextrin/niaouli essential oil (β-CD/NEO) inclusion complex (such as 1:1, 1:3, and 1:5) on the morphological (SEM), thermal (TGA), physical (FT-IR), wettability (contact angle), and mechanical (tensile test) characteristics of PVA/inulin films were investigated. Moreover, the antibacterial activities against the Gram (-) (Escherichia coli and Pseudomonas aeruginosa) and Gram (+) (Staphylococcus aureus) bacteria of the obtained films were studied. From the morphological analysis, good emulsion stability and porosity were obtained in the Pickering films with the highest oil content, while instability was observed in the Pickering films with the lowest concentration of oil content. Thermal and spectroscopic analysis indicated there was no significant difference between the Pickering emulsion films and neat films. With the addition of Pickering emulsions, the tensile stress values decreased from 7.3 ± 1.9 MPa to 3.3 ± 0.2. According to the antibacterial efficiency results, films containing pumpkin powder and Pickering emulsion films containing both pumpkin powder and a ratio of 1:1 (β-CD/NEO) did not have an antibacterial effect, while Pickering emulsion films with a ratio of (β-CD/NEO) 1:3 and 1:5 showed an antibacterial effect against Escherichia coli, with a zone diameter of 12 cm and 17 cm, respectively. Among the samples, the films with ratio of (β-CD/NEO) 1:5 had the highest antioxidant capacity, as assessed by DPPH radical scavenging at 12 h intervals. Further, none of the samples showed any cytotoxic effects the according to LDH and WST-1 cytotoxicity analysis for the NIH3T3 cell line. Ultimately, it is expected that these films are completely bio-based and may be potential candidates for use in wound healing applications.

Ginger Essential Oil as an Active Addition to Composite Chitosan Films: Development and Characterization

The recent interest in food biopackaging is showing an increasing trend, especially in the development of antimicrobial coatings and films. The focus of this study is to assess the potential application of ginger (Zingiber officinale) essential oil (GEO) to polysaccharide films based on chitosan (CHf) and their utilization as an active edible packaging. The films were characterized by different instrumental techniques, and data indicated significant differences (p < 0.05) in the chemical composition of the samples. Forty-seven active compounds from ginger rhizomes were identified in the examined essential oil by gas chromatography mass spectrometer (GC-MS). Fourier transforms infrared spectra (FT-IR) confirmed an interaction between the hydroxyl groups of the phenolic compounds of the essential oil and the amine groups of the bioactive matrix, as shown by the peaks at wavenumbers 1639 cm−1 and 1558 cm−1. X-ray diffraction data suggested a lower crystallinity in the CHf due to the addition of GEO. Differential scanning calorimetric (DSC) analysis revealed that the CHf possessed high thermal stability, especially when different concentrations of GEO were added. The bioactive CHf showed distinct activity against both Gram-positive and Gram-negative bacteria, such as Staphylococcus aureus, Bacillus subtilis, Streptococcus sp., Escherichia coli, Salmonella sp., and Pseudomonas aeruginosa, thus improving the antimicrobial activity to these films. The results provide a comprehensive insight into the importance of films with incorporated EOs as novel types of active food packaging. Antimicrobial food packaging is one of the most promising kinds of active packaging, and acts to reduce, inhibit, or retard any microorganism growth that could contaminate packaged food items.

Preparation and characterization of oregano essential oil-loaded Dioscorea zingiberensis starch film with antioxidant and antibacterial activity and its application in chicken preservation

In this study, abundant starch was separated from the industrial crop Dioscorea zingiberensis C.H. Wright (DZW), and a novel bioactive packaging film loaded with oregano essential oil (OEO) was prepared and characterized. NaClO solution worked as a bleacher to prepare uniform starch powder from DZW tubers. OEO was selected from among three essential oils of Labiatae family plants for its strongest antibacterial activity. After the addition of OEO into the starch-based film, the UV-vis shielding property and antioxidant activity were enhanced. Meanwhile, the films still have a considerable performance in transparency, mechanical strength and water vapor permeability after incorporated with OEO. Furthermore, the 3% OEO-loaded starch film exhibited the strongest antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. It effectively lowered the total viable count of fresh chicken under 4 °C preservation conditions. These results revealed that the OEO-loaded DZW starch film can exert a positive effect on maintaining the quality and extending the shelf life of fresh meat. Therefore, readily accessible DZW tubers and oregano are very promising resources for application in degradable bioactive packaging film.

Sodium Alginate and Chitosan as Components Modifying the Properties of Inulin Hydrogels

The aim of the study was to investigate the influence of addition of sodium alginate (SA) and chitosan (CH) on the properties of inulin hydrogels. Inulin hydrogels (20 g/100 g) containing various additions (0.0, 0.1, 0.3, and 0.5 g/100 g) of SA and CH were produced. The hydrogels' properties were assessed based on the volumetric gel index, microstructure, yield stress, texture, stability, and color parameters. According to the findings, the inclusion of these polysaccharides had no influence on the gelation ability of the inulin solution. The physical properties of the hydrogels containing SA or CH differed from hydrogels containing only inulin (INU). The obtained microstructural pictures revealed that the addition of SA and CH resulted in the formation of hydrogels with a more compact, smooth, and cohesive structure. Consequently, they had higher yield stress, strength, and spreadability values than INU hydrogels. The addition of chitosan in comparison with sodium alginate also had a greater effect in strengthening the structure of hydrogels, especially at the level of 0.5 g/100 g. For example, the addition of this amount of SA increased the yield stress on average from 195.0 Pa (INU) to 493.6 Pa, while the addition of CH increased it to 745.3 Pa. In the case of the strength parameter, the addition of SA increased the force from 0.24 N (INU) to 0.42 N and the addition of CH increased it to 1.29 N. In the case of spreadability this increase was from 2.89 N * s (INU) to 3.44 N * s (SA) and to 6.16 N * s (CH). Chitosan also caused an increase in the stability of inulin hydrogels, whereas such an effect was not observed with the addition of sodium alginate. The gels with the addition of SA and CH also had significantly different values of color parameters. Inulin-alginate hydrogels were characterized by higher values of the color parameter a *, lower values of the color parameter b *, and in most concentrations higher values of the color parameter L * compared to inulin-chitosan hydrogels. Based on the collected data, it can therefore be concluded that through the addition of sodium alginate and chitosan, there is a possibility to modify the properties of inulin hydrogels and, consequently, to better adapt them to the characteristics of the pro-health food products in which they will be used.

Improvement of the Antimicrobial Activity of Oregano Oil by Encapsulation in Chitosan-Alginate Nanoparticles

Oregano oil (OrO) possesses well-pronounced antimicrobial properties but its application is limited due to low water solubility and possible instability. The aim of this study was to evaluate the possibility to incorporate OrO in an aqueous dispersion of chitosan—alginate nanoparticles and how this will affect its antimicrobial activity. The encapsulation of OrO was performed by emulsification and consequent electrostatic gelation of both polysaccharides. OrO-loaded nanoparticles (OrO-NP) have small size (320 nm) and negative charge (−25 mV). The data from FTIR spectroscopy and XRD analyses reveal successful encapsulation of the oil into the nanoparticles. The results of thermogravimetry suggest improved thermal stability of the encapsulated oil. The minimal inhibitory concentrations of OrO-NP determined on a panel of Gram-positive and Gram-negative pathogens (ISO 20776-1:2006) are 4–32-fold lower than those of OrO. OrO-NP inhibit the respiratory activity of the bacteria (MTT assay) to a lower extent than OrO; however, the minimal bactericidal concentrations still remain significantly lower. OrO-NP exhibit significantly lower in vitro cytotoxicity than pure OrO on the HaCaT cell line as determined by ISO 10993-5:2009. The irritation test (ISO 10993-10) shows no signs of irritation or edema on the application site. In conclusion, the nanodelivery system of oregano oil possesses strong antimicrobial activity and is promising for development of food additives.

Optimization of Aqueous Extraction Conditions of Inulin from the Arctium lappa L. Roots Using Ultrasonic Irradiation Frequency

Ultrasound-assisted extraction is a promising technique to obtain active compounds from plants with high efficiency. The present study was conducted in two sections. In the first phase, the effect of solvent type (methanol, ethanol, water, and water-ethanol (50 : 50, v/v)) on inulin extraction yield from burdock roots (Arctium lappa L.) was investigated by the conventional method. The second phase aim was to optimize the condition of inulin and phenolic compounds including sonication time (10–40 min), sonication temperature (40–70°C), and solid/solvent ratio (1 : 20–1:40 g/ml) using response surface methodology (RSM). The results demonstrated that the highest inulin efficiency was extracted by water in the conventional method, which is equal to 10.32%. The optimum conditions of ultrasound-assisted water extraction for independent variables including sonication time and temperature as well as solid/water ratio were 36.65 min, 55.48°C, and 1 : 35 g/ml, respectively, which were determined on the maximization of inulin and total phenol content and minimization of IC50. At this optimum condition, inulin yield, phenolic compounds, and IC50 were found to be 12.46%, 18.85 mg GA/g DW, and 549.85 µg/ml, respectively. Regarding the results of this research, ultrasound-assisted extraction can be used as an alternative to the conventional extraction methods in extracting bioactive compounds from medicinal plants because it may improve the mass transfer, reducing the extraction time and the solvent used.

Promising nanomaterials in the fight against malaria

For more than one hundred years, several treatments against malaria have been proposed but they have systematically failed, mainly due to the occurrence of drug resistance in part resulting from the exposure of the parasite to low drug doses. Several factors are behind this problem, including (i) the formidable barrier imposed by the Plasmodium life cycle with intracellular localization of parasites in hepatocytes and red blood cells, (ii) the adverse fluidic conditions encountered in the blood circulation that affect the interaction of molecular components with target cells, and (iii) the unfavorable physicochemical characteristics of most antimalarial drugs, which have an amphiphilic character and can be widely distributed into body tissues after administration and rapidly metabolized in the liver. To surpass these drawbacks, rather than focusing all efforts on discovering new drugs whose efficacy is quickly decreased by the parasite's evolution of resistance, the development of effective drug delivery carriers is a promising strategy. Nanomaterials have been investigated for their capacity to effectively deliver antimalarial drugs at local doses sufficiently high to kill the parasites and avoid drug resistance evolution, while maintaining a low overall dose to prevent undesirable toxic side effects. In recent years, several nanostructured systems such as liposomes, polymeric nanoparticles or dendrimers have been shown to be capable of improving the efficacy of antimalarial therapies. In this respect, nanomaterials are a promising drug delivery vehicle and can be used in therapeutic strategies designed to fight the parasite both in humans and in the mosquito vector of the disease. The chemical analyses of these nanomaterials are essential for the proposal and development of effective anti-malaria therapies. This review is intended to analyze the application of nanomaterials to improve the drug efficacy on different stages of the malaria parasites in both the human and mosquito hosts.

Burdock (Arctium lappa L) roots as a source of inulin-type fructans and other bioactive compounds: Current knowledge and future perspectives for food and non-food applications

The roots and tubers of the Asteraceae family are known as a source of various oligosaccharides, and chicory roots and Jerusalem artichoke have stood out for its commercial viability. However burdock root (Arctium lappa L.), which is adapted to temperate climate, moist, and sandy soil, is still unknown as health food in the western world. This review showed the potential of burdock roots as a source of prebiotic fibers, chlorogenic acids, cinnarine, lignans, and quercetin. The extraction methods of burdock functional compounds are made with water, temperature and time variations only. Biological assays showed antioxidant activity, anti-inflammatory, and hypolipidemic properties, and gastric mucosal defense mechanisms, among others. Therefore, the use of burdock roots as functional food should be encouraged in countries that have imported products derived from other roots of the same family for health benefits.

Fat replacement by pecan nut and oregano oil and their impact on the physicochemical properties and consumer acceptability of frankfurters

Objective

A study was conducted to determine the physicochemical quality and consumer acceptability of beef frankfurter-type sausages formulated with pecan nut paste and Mexican oregano oil (MO) of two varieties, Poliomintha longiflora Gray (Mexican oregano Poliomintha, MOP) or Lippia berlandieri (Mexican oregano Lippia, MOL).

Methods

Frankfurters were processed under six treatment conditions: control (10.67% pork fat), MOP (control + 0.01% MOP), MOL (control + 0.01% MOL), MOP-N (control + 0.01% MOP + 6% pecan nut paste), MOL-N (control + 0.01% MOL + 6% pecan nut paste), and C-N (control + 6% pecan nut paste). The physicochemical properties and the consumer acceptability were determined.

Results

The addition of MO and nut did not influence the water holding capacity, drip loss, and luminosity of frankfurters, but those ingredients increased pH and shear force (p<0.05) and decreased redness (p<0.05) of frankfurters. Frankfurters were generally well accepted by consumers. However, general acceptability of sausages decreased with the addition of MO. Control sausages showed the highest acceptability.

Conclusion

The MO and pecan nut paste do not affect drastically the quality of frankfurters. These results provide evidence that partial replacement of pork fat by pecan nut in frankfurters maintain a consistent physicochemical quality and its commercialization looks promising given consumers' acceptance.

A Recent Insight Regarding the Phytochemistry and Bioactivity of Origanum vulgare L. Essential Oil

Origanum vulgare L. is a widely used aromatic plant, especially due to its content in essential oil, mainly rich in carvacrol and thymol. The ethnopharmacological uses of Origanum vulgare L. essential oil (OEO) comprise digestive, respiratory, or dermatological disorders. The review focuses on the increasing number of recent studies investigating several biological activities of OEO. The bioactivities are in tight relation to the phytochemical profile of the essential oil, and also depend on taxonomic, climatic, and geographical characteristics of the plant material. The antibacterial, antifungal, antiparasitic, antioxidant, anti-inflammatory, antitumor, skin disorders beneficial effects, next to antihyperglycemic and anti-Alzheimer activities were reported and confirmed in multiple studies. Moreover, recent studies indicate a positive impact on skin disorders of OEO formulated as nanocarrier systems in order to improve its bioavailability and, thus, enhancing its therapeutic benefits. The review brings an up to date regarding the phytochemistry and bioactivity of Origanum vulgare L. essential oil, underlining also the most successful pharmaceutical formulation used for skin disorders.

Characteristics of karaya gum based films: Amelioration by inclusion of Schisandra chinensis oil and its oleogel in the film formulation

This research was focused to develop novel karaya gum films, modified by adding Schisandra chinensis oil and its oleogel. The films produced were assessed for physicochemical, mechanical, thermal and structural characteristics. Glass transition temperature (Tg) of control karaya gum films was recorded as 145.70 °C. Insignificant (p < 0.05) changes occurred in Tg of films in which oil was incorporated, irrespective of the concentration. However, Tg decreased significantly (p < 0.05) as oleogel was added to the karaya gum films and lowest Tg occurred for the KGOG3 films which contained highest concentration of oleogel. X-ray diffraction test depicted an obsolete amorphous behavior of control karaya gum film whereas some peaks appeared in other film samples. Scanning electron micrography (SEM) revealed a reduction in roughness and grainy morphology when oil or oleogel was added to the films. Addition of oil/oleogel enhanced the phenolic content and DPPH radical scavenging activity of the films.

Developing multicomponent edible films based on chitosan, hybrid of essential oils, and nanofibers: Study on physicochemical and antibacterial properties

Plastic waste is one of the major threats to the environment, and an urgent need to replace synthetic plastics with sustainable materials is progressively growing. Herein, sustainable films based on chitosan, Satureja, and Thyme essential oils (EOs), and chitosan nanofibers (NF) were developed for the first time. To this end, 1% (w/w) of EOs and 2 wt% of NF were incorporated into the chitosan solution. Despite the very similar chemical structure of carvacrol and thymol, which are the major constituents of Satureja and Thyme EOs, respectively, they imposed notably different effects on the physicochemical properties of chitosan films. Thyme EO was more efficient at establishing hydrogen bonds with chitosan. The disruptive effect of EOs on the crystalline network of chitosan was demonstrated through X-ray diffraction analysis. Satureja and Thyme EOs decreased and increased the barrier property of the chitosan films against water vapor, respectively. However, the barrier property was greatly improved in the presence of chitosan nanofibers. Satureja EO exhibited a more efficient antibacterial property against E. coli rather than Thyme EO. The fruits and vegetables, coated by the chitosan/EO/NF system, were less perished as compared with the control and chitosan-coated samples indicating the promising potential of the developed system to be used as edible and sustainable films and coatings due to their enhanced antibacterial and barrier properties.

Chitosan Nanofiber and Cellulose Nanofiber Blended Composite Applicable for Active Food Packaging

This paper reports that, by simply blending two heterogeneous polysaccharide nanofibers, namely chitosan nanofiber (ChNF) and cellulose nanofiber (CNF), a ChNF–CNF composite was prepared, which exhibited improved mechanical properties and antioxidant activity. ChNF was isolated using the aqueous counter collision (ACC) method, while CNF was isolated using the combination of TEMPO oxidation and the ACC method, which resulted in smaller size of CNF than that of ChNF. The prepared composite was characterized in terms of morphologies, FT-IR, UV visible, thermal stability, mechanical properties, hygroscopic behaviors, and antioxidant activity. The composite was flexible enough to be bent without cracking. Better UV-light protection was shown at higher content of ChNF in the composite. The high ChNF content showed the highest antioxidant activity in the composite. It is the first time that a simple combination of ChNF–CNF composites fabrication showed good mechanical properties and antioxidant activities. In this study, the reinforcement effect of the composite was addressed. The ChNF–CNF composite is promising for active food packaging application.

Repositioning Natural Antioxidants for Therapeutic Applications in Tissue Engineering

Although a large panel of natural antioxidants demonstrate a protective effect in preventing cellular oxidative stress, their low bioavailability limits therapeutic activity at the targeted injury site. The importance to deliver drug or cells into oxidative microenvironments can be realized with the development of biocompatible redox-modulating materials. The incorporation of antioxidant compounds within implanted biomaterials should be able to retain the antioxidant activity, while also allowing graft survival and tissue recovery. This review summarizes the recent literature reporting the combined role of natural antioxidants with biomaterials. Our review highlights how such functionalization is a promising strategy in tissue engineering to improve the engraftment and promote tissue healing or regeneration.

Antioxidant and antimicrobial applications of biopolymers: A review

Biopolymers have generated mounting interest among researchers and industrialists over the recent past. Rising consciousness on the use of eco-friendly materials as green alternatives for fossil-based biopolymers has shifted the research focus towards biopolymers. Advances in technologies have opened up new windows of opportunities to explore the potential of biopolymers. In this context, this review presents a critique on applications of biopolymers in relation to antioxidant and antimicrobial activities. Some biopolymers are reported to contain inherent antioxidant and antimicrobial properties, whereas, some biopolymers, which do not possess such inherent properties, are used as carriers for other biopolymers or additives having these properties. Modifications are often performed in order to improve the properties of biopolymers to suit them for different applications. This review aims at presenting an overview on recent advances in the use of biopolymers with special reference to their antioxidant and antimicrobial applications in various fields.

From waste/residual marine biomass to active biopolymer-based packaging film materials for food industry applications – a review

Waste/residual marine biomass represents a vast and potentially underexplored source of biopolymers chitin/chitosan and alginate. Their isolation and potential application in the development and production of bio-based food packaging are gaining in attractiveness due to a recent increment in plastic pollution awareness. Accordingly, a review of the latest research work was given to cover the pathway from biomass sources to biopolymers isolation and application in the development of active (antimicrobial/antioxidant) film materials intended for food packaging. Screening of the novel eco-friendly isolation processes was followed by an extensive overview of the most recent publications covering the chitosan- and alginate-based films with incorporated active agents.

Effect of java citronella essential oil addition on the physicochemical properties of Gelidium corneum-chitosan composite films

A new composite film was developed by combining Gelidium corneum (GC) with chitosan to enhance the physicochemical characteristics of GC film. In addition, to confer new functional property on the GC-chitosan composite film, various amounts (0.5%, 1.0%, and 1.5%) of java citronella essential oil (JCEO) were incorporated into the film. As the concentration of JCEO increased, the extensibility of the GC-chitosan film improved. In addition, the film became more opaque due to decreased light transmission. Especially, ultraviolet light was completely blocked in the composite films containing JCEO. Radical scavenging activities of the films also increased with increasing JCEO content, indicating that the films have antioxidant activity. Therefore, GC-chitosan composite film containing JCEO is applicable in food packaging to preserve food quality by retarding lipid oxidation.

Effect of Sonication on the Properties of Flaxseed Gum Films Incorporated with Carvacrol

Carvacrol is a natural compound known to be a highly effective antibacterial; however, it is a hydrophobic molecule, which is a limitation to its use within food packaging. Flaxseed gum (FG) films containing different contents of carvacrol (C) were produced by a film-casting method with sonication. The effects of sonication power and time on the properties of the FG-C films were investigated by measuring the film thickness, mechanical properties, contact angle, opacity, water vapor permeability (WVP), water sorption isotherm, Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry (DSC), antibacterial and antioxidant activities, and microstructure. The results showed that sonication power and time had significant effects on mechanical and barrier properties, film opacity, and degradability (p < 0.05). The tensile strength (TS) and elongation at break (EB) values exhibited an obvious improvement after sonication, and FG-0.5C-6030 had the lowest TS (33.40 MPa) and EB (4.46%) values. FG-C films formed a denser structure and the contact angle was improved as a result of sonication, which improved the integration of carvacrol into the FG matrix. In terms of microstructure, sonication resulted in a homogeneous and continuous crosssection of FG-C films, and regular surface and cross-sectional images were obtained through the highest acoustic intensity and longest time treatment. The FG films incorporated with carvacrol displayed antibacterial properties against Staphylococcus aureus, Vibrio parahaemolyticus, Shewanella putrefaciens, and Pseudomonas fluorescens, as well as increased antioxidant properties, and sonication was proven to enhance both of them.

Antimicrobial Activity of Oregano Essential Oil Incorporated in Sodium Alginate Edible Films: Control of Listeria monocytogenes and Spoilage in Ham Slices Treated with High Pressure Processing

The aim of the study was to evaluate the efficacy of oregano essential oil (OEO) incorporated in Na-alginate edible films when applied to sliced ham inoculated with a cocktail of Listeria monocytogenes strains, with or without pretreatment by high pressure processing (HPP). Microbiological, physicochemical and sensory analyses (in Listeria-free slices) were performed, while, the presence/absence and the relative abundance of each Listeria strain, was monitored by pulsed field gel electrophoresis (PFGE). The OEO incorporation in the films, caused approximately 1.5 log reduction in Listeria population at 8 and 12 °C at the end of the storage period, and almost 2.5 log reduction at 4 °C. The HPP treatment caused 1 log reduction to the initial Listeria population, while levels kept on decreasing throughout the storage for all the tested temperatures. The pH of the samples was higher in the cases where HPP was involved, and the samples were evaluated as less spoiled. Furthermore, the presence of OEO in the films resulted in color differences compared to the control samples, whilst the aroma of these samples was improved. In conclusion, the combined application of HPP and OEO edible films on the slices, led to a significant reduction or absence of the pathogen.

Recent Developments in the Reduction of Oxidative Stress through Antioxidant Polymeric Formulations

Reactive oxygen and nitrogen species (RONS) are produced endogenously in our body, or introduced through external factors, such as pollution, cigarette smoke, and excessive sunlight exposure. In normal conditions, there is a physiological balance between pro-oxidant species and antioxidant molecules that are able to counteract the detrimental effect of the former. Nevertheless, when this homeostasis is disrupted, the resulting oxidative stress can lead to several pathological conditions, from inflammation to cancer and neurodegenerative diseases. In this review, we report on the recent developments of different polymeric formulations that are able to reduce the oxidative stress, from natural extracts, to films and hydrogels, and finally to nanoparticles (NPs).

Application of Adzuki Bean Starch in Antioxidant Films Containing Cocoa Nibs Extract

In this study, starch extracted from adzuki bean (ABS) was used as a biodegradable film source. In addition, to develop a new antioxidant film, various amounts of cocoa nibs extract (CNE, 0.3%, 0.7%, and 1%) were incorporated. With the addition of CNE, the elongation at break of the ABS films increased and the tensile strength decreased. The ABS films with CNE showed increased 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities with increasing amounts of CNE. In particular, the ABTS and DPPH radical scavenging activities of the ABS films containing 1% CNE were 100% and 94.9%, respectively. Furthermore, decomposition of the films was observed after 28 days of biodegradation. Thus, ABS films containing CNE can be applied as a new active packaging material.