Surface attachment of active antimicrobial coatings onto conventional plastic-based laminates and performance assessment of these materials on the storage life of vacuum packaged beef sub-primals

Optimized hybrid edible surface coating prepared with gelatin and cellulose nanofiber for cherry tomato preservation

The use of renewable bioresources and their nanoforms in developing edible coating materials is considered a promising approach for preserving food freshness. Herein, cellulose nanofibers (CNF) with different morphologies were combined with gelatin to prepare composite preservation film following by brushing over the surface of cherry tomatoes as an edible coating. The gelatin-based composite film containing 0.3 % CNF20 (GC2-0.3) exhibited the lowest water vapor permeability (WVP, 1.97 × 10-4 barrer), lower oxygen permeability (OP, 2.54 × 10-2 barrer), higher transparency (Tr = 85.28 %) and excellent mechanical properties (σ = 47.45 MPa, E = 1.84 GPa). When coated on cherry tomatoes, it maintained good luster and freshness, significantly reducing the water loss of cherry tomatoes. The weight loss was only 16 % after 14 days of storage at 25 °C and 30 % humidity, compared to >30 % for the uncoated cherry tomatoes. This work provides a viable strategy for developing sustainable, green fresh-keeping materials that can prolong the storage time of the putrescible food.

Cold Atmospheric Pressure Plasma Solutions for Sustainable Food Packaging

Increasing the number of resistant bacteria resistant to treatment is one of the leading causes of death worldwide. These bacteria are created in wounds and injuries and can be transferred through hospital equipment. Various attempts have been made to treat these bacteria in recent years, such as using different drugs and new sterilization methods. However, some bacteria resist drugs, and other traditional methods cannot destroy them. In the meantime, various studies have shown that cold atmospheric plasma can kill these bacteria through different mechanisms, making cold plasma a promising tool to deactivate bacteria. This new technology can be effectively used in the food industry because it has the potential to inactivate microorganisms such as spores and microbial toxins and increase the wettability and printability of polymers to pack fresh and dried food. It can also increase the shelf life of food without leaving any residue or chemical effluent. This paper investigates cold plasma's potential, advantages, and disadvantages in the food industry and sterilization.

Pharmacological Potential of Kaempferol, a Flavonoid in the Management of Pathogenesis via Modulation of Inflammation and Other Biological Activities

Natural products and their bioactive compounds have been used for centuries to prevent and treat numerous diseases. Kaempferol, a flavonoid found in vegetables, fruits, and spices, is recognized for its various beneficial properties, including its antioxidant and anti-inflammatory potential. This molecule has been identified as a potential means of managing different pathogenesis due to its capability to manage various biological activities. Moreover, this compound has a wide range of health-promoting benefits, such as cardioprotective, neuroprotective, hepatoprotective, and anti-diabetic, and has a role in maintaining eye, skin, and respiratory system health. Furthermore, it can also inhibit tumor growth and modulate various cell-signaling pathways. In vivo and in vitro studies have demonstrated that this compound has been shown to increase efficacy when combined with other natural products or drugs. In addition, kaempferol-based nano-formulations are more effective than kaempferol treatment alone. This review aims to provide detailed information about the sources of this compound, its bioavailability, and its role in various pathogenesis. Although there is promising evidence for its ability to manage diseases, it is crucial to conduct further investigations to know its toxicity, safety aspects, and mechanism of action in health management.

In Vitro Antioxidant and Antimicrobial Properties of Composite Flour Formulations Developed Using Selected Local Grain Varieties

The aim of this study was to determine the in vitro antioxidant potential of four extruded and domestically prepared composite flour formulations developed by composting selected locally available grain varieties in Sri Lanka. The potential of the flour extracts to scavenge free radicals were evaluated by performing DPPH, ABTS, and FRAP assays. Furthermore, the antimicrobial activities of the flour formulations against selected Gram-positive and Gram-negative pathogenic microorganisms were comparatively evaluated using agar well diffusion and disk diffusion assays. Ethanol and water extracts of the samples were evaluated for their antimicrobial potential. The results showed that extruded samples possessed high antioxidant properties than samples prepared using the conventional cooking. Furthermore, the antioxidant potential of the formulations evaluated using different assays was strongly correlated. Moreover, the formulations reported positive antimicrobial potential against tested Gram-negative and Gram-positive bacteria. The ethanol extracts of flour formulations exhibited higher susceptibility to tested microbes than that of water extracts while agar well diffusion resulted significantly high inhibition against pathogenic bacteria than that of agar disk diffusion method (p < 0.05). In overall, the highest inhibition zone of 17.64 mm was depicted by F4 against Salmonella, while the lowest diameter of 6.09 mm was depicted by F1 against Listeria. In conclusion, the developed flour formulations contained natural antimicrobial agents which can combat common food spoilage and pathogenic bacteria and can be promoted as value-added products with health benefits beyond nutrition.

Improving the quality of the chicken fillet using chitosan, gelatin, and starch coatings incorporated with bitter orange peel extract during refrigeration

The preserving potential of biopolymer coatings can be improved by adding natural antimicrobial and antioxidant compounds. The objective of this study was to evaluate the effect of natural coatings (gelatin (Gel), chitosan (Ch), and modified starch (MS)) incorporated with bitter orange peel extract (BOE) on the quality of the chicken fillets during cold. BOE had a high amount of phenolic compounds (145.28 mgGAE/g). Coating the fillets with pure BOE exerted a higher inhibitory effect against bacterial growth compared to composite coatings without extract. Lower microbial count (2-3 log CFU/g on days 9 and 12 of storage) was observed in the samples coated with composite biopolymers incorporated with BOE in comparison to the coatings without BOE. Composite coatings of Gel/MS/BOE showed lower FFA in the fillets followed by Gel/Ch/BOE and MS/Ch/BOE. The lowest TVB-N belonged to MS/Ch/BOE followed by Gel/Ch/BOE and Gel/MS/BOE which were 17.05, 17.39, and 19.40 mg/100 g at the end of the storage. Among the samples, pure BOE, Gel/MS/BOE, Gel/Ch/BOE, and MS/Ch/BOE showed the lowest peroxide value and the coatings containing chitosan had a slower rate of hydroperoxide generation. Drip loss showed a descending trend in all coated samples except for an enhancement in control and BOE-coated fillets, 6.42% and 6.39%, respectively, on day 12 of storage. Samples coated with Gel/MS and Gel/MS/BOE had the lowest drip loss during the storage period (5.96% and 5.98%, respectively). It should be noted that coatings containing chitosan had higher antimicrobial and antioxidant effects. The effect of the coatings as antimicrobial barriers and preservative agents were as follows: Gel/Ch/BOE > MS/Ch/BOE > Gel/MS/BOE. It can be concluded that the applied composite coatings in this work have a high potential to maintain and improve the quality of raw chicken fillets during storage in the refrigerator.

Physicochemical and functional characterization of gelatin edible film incorporated with fucoidan isolated from Sargassum tenerrimum

Biodegradable films were created with fish gelatin and fucoidan extracted from Sargassum tenerrimum using 30% glycerol as a plasticizer. The gelatin films were incorporated with fucoidan (2.5%, 5%, 7.5%, and 10%), respectively. Results presented that the average thickness of films ranged from 0.12 to 0.147 mm. Tensile strength (TS) was decreased from 29.27 to 3.46 MPa by adding the fucoidan except for the gelatin/fucoidan 10% (5.35 MPa) sample. The results showed that the physical characteristics (the contact angle (Ɵ), water solubility, opacity, and moisture content) of the films significantly changed depending on different fucoidan concentrations. FTIR and SEM analysis confirmed the interaction of fucoidan with gelatin in the composite film. Furthermore, adding 10% fucoidan showed high DPPH radical scavenging activity (65%) than other treatments. Therefore, incorporation of fucoidan extracted from brown algae (Sargassum tenerrimum) with fish gelatin films improved thermal stability, anti-oxidative, and antibacterial characteristics in addition to enhanced mechanical and protective properties, to be used as a bioactive edible film in the food packaging industry.

Natural Compounds with Antimicrobial Properties in Cosmetics

Currently, the cosmetic industry is a very intensively growing part of the economy. Consumer demands are adapted to the current lifestyle, which is based on technological innovations and awareness of the impact of various factors on human health and fitness. There is growing interest in cosmetics based on environmentally friendly natural compounds exerting health-promoting effects. Chemicals with antimicrobial properties used as ingredients in cosmetics ensure their durability and safety. Polyphenolic compounds, peptides, essential oils, and plant extracts characterized by these properties are natural ingredients that can replace synthetic components of cosmetics. The advantage of these compounds is that they exhibit antioxidant, anti-inflammatory, and soothing properties, enhancing the product value in addition to their antimicrobial properties. This review article describes the antimicrobial properties of natural compounds that can protect cosmetics and can replace previously used preservative agents. Various studies indicate that the use of these compounds increases consumer interest in these products and has a positive impact on the environment.

A Review of Regulatory Standards and Advances in Essential Oils as Antimicrobials in Foods

As essential oils (EOs) possess GRAS status, there is a strong interest in their application to food preservation. Trends in the food industry suggest consumers are drawn to environmentally friendly alternatives and less synthetic chemical preservatives. Although the use of EOs has increased over the years, adverse effects have limited their use. This review aims to address the regulatory standards for EO usage in food, techniques for delivery of EOs, essential oils commonly used to control pathogens and molds, and advances with new active compounds that overcome sensory effects for meat products, fresh fruits and vegetables, fruit and vegetable juices, seafood, dairy products, and other products. This review will show adverse sensory effects can be overcome in various products by the use of edible coatings containing encapsulated EOs to facilitate the controlled release of EOs. Depending on the method of cooking, the food product has been shown to mask flavors associated with EOs. In addition, using active packaging materials can decrease the diffusion rate of the EOs, thus controlling undesirable flavor characteristics while still preserving or prolonging the shelf life of food. The use of encapsulation in packaging film can control the release of volatile or active ingredients. Further, use of EOs in the vapor phase allows for contact indirectly, and use of nanoemulsion, coating, and film wrap allows for the controlled release of the EOs. Research has also shown that combining EOs can prevent adverse sensory effects. Essential oils continue to serve as a very beneficial way of controlling undesirable microorganisms in food systems.

Parameters Affecting the Water Vapour Permeability of Gelatin Films as Evaluated by the Infrared Detecting Method ASTM F1249

The purpose of this study was to assess testing parameters for measurement of water vapour permeability (WVP) properties of bovine gelatin films by ASTM F1249. This method utilises an infrared sensor to determine the WVP of conventional plastic-based films and has been widely applied within the packaging industry, but has had very limited application with hydrophilic compostable/edible packaging materials. These films have low WVP properties with highly variable WVP values (as studied by ASTM E96); consequently, this parameter has to be carefully controlled. Assessment of the module was carried out using bovine gelatin films with different thicknesses of film, and gelatin was chosen as an example of such film types using the following Mocon Permatran testing parameters: 50 or 70% relative humidity (RH), 100 or 150 cm3 nitrogen gas flow rates for the module’s RH-cell (100 cm3 for all other cells). In all cases, WVP increased with an increase in gas flow rate. This method showed that WVP increased with increasing gelatin film thickness, and categorically supports previous—and often unexplained—WVP findings for other hydrophilic, biopolymer films. The current study is a helpful guide to the examination of water barrier properties of hydrophilic edible/biodegradable/compostable packaging materials in research and industry.

Application of bi-layers active gelatin films for sliced dried-cured Coppa conservation

Processed meat products have been increasingly consumed, a highlight being dried-cured coppa, commonly purchased sliced, making it more susceptible to bacterial deterioration and lipid oxidation. The aim of this work was to produce and apply bi-layers films based on gelatin (in both layers) with addition of nisin and/or Pitanga leaf hydroethanolic extract (PLHE) only in the food contact thinner layer, in order to evaluate their effect on the refrigerated storage of sliced dried-cured coppa. Dried-cured coppa slices covered with active films were vacuum-packaged and stored under refrigeration for 120 days. Every 30 days, samples were tested for moisture content, water activity, pH, color parameters, lipid oxidation by TBARS and peroxide index methods, and microbiological analysis. The different film formulations presented no influence on the water activity, pH and color parameters of sliced dried-cured coppa. However, they significantly affected moisture content, bacterial count and lipid oxidation. The addition of both active compounds - nisin and PLHE - in the food contact thinner layer was observed to have the most favorable effect.

Protein-based natural antibacterial materials and their applications in food preservation

Plastics materials used for food packaging are recalcitrant, leading to a growing global environmental problem, which arouses the attention of environmental protection departments in many countries. Therefore, to meet the increasing demand for sustainable and environment-friendly consumer products, it is necessary for the food industry to develop natural antibacterial materials for food preservation. This review summarizes the common biodegradable natural antimicrobial agents and their applications in food preservation; as well as an overview of five commonly used biodegradable protein-based polymers, such as zein, soy protein isolate, gelatin and whey protein, with special emphasis on the advantages of protein-based biopolymers and their applications in food packaging industry.

Natural Anti-Microbials for Enhanced Microbial Safety and Shelf-Life of Processed Packaged Meat

Microbial food contamination is a major concern for consumers and food industries. Consumers desire nutritious, safe and “clean label” products, free of synthetic preservatives and food industries and food scientists try to meet their demands by finding natural effective alternatives for food preservation. One of the alternatives to synthetic preservatives is the use of natural anti-microbial agents in the food products and/or in the packaging materials. Meat and processed meat products are characteristic examples of products that are highly perishable; hence natural anti-microbials can be used for extending their shelf-life and enhancing their safety. Despite several examples of the successful application of natural anti-microbial agents in meat products reported in research studies, their commercial use remains limited. This review objective is to present an extensive overview of recent research in the field of natural anti-microbials, covering essential oils, plant extracts, flavonoids, animal-derived compounds, organic acids, bacteriocins and nanoparticles. The anti-microbial mode of action of the agents, in situ studies involving meat products, regulations and, limitations for usage and future perspectives are described. The review concludes that naturally derived anti-microbials can potentially support the meat industry to provide “clean label”, nutritious and safe meat products for consumers.

Antimicrobial Properties and Mechanism of Action of Some Plant Extracts Against Food Pathogens and Spoilage Microorganisms

This work aims to evaluate the antimicrobial potential of ethanolic and water extracts of roselle (Hibiscus sabdariffa), rosemary (Rosmarinus officinalis), clove (Syzygium aromaticum), and thyme (Thymus vulgaris) on some food pathogens and spoilage microorganisms. Agar well diffusion method has been used to determine the antimicrobial activities and minimum inhibitory concentrations (MIC) of different plant extracts against Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Salmonella enteritidis, Vibrio parahaemolyticus, and Pseudomonas aeruginosa), and one fungus (Candida albicans). The extracts exhibited both antibacterial and antifungal activities against tested microorganisms. Ethanolic roselle extract showed significant antibacterial activity (P < 0.05) against all tested bacterial strains, while no inhibitory effect on Candida albicans (CA) was observed. Only the ethanolic extracts of clove and thyme showed antifungal effects against CA with inhibition zones ranging from 25.2 ± 1.4 to 15.8 ± 1.2 mm, respectively. Bacillus cereus (BC) appears to be the most sensitive strain to the aqueous extract of clove with a MIC of 0.315%. To enhance our understanding of antimicrobial activity mechanism of plant extracts, the changes in internal pH (pHint), and membrane potential were measured in Staphylococcus aureus (SA) and Escherichia coli (EC) cells after exposure to the plant extracts. The results indicated that the plant extracts significantly affected the cell membrane of Gram-positive and Gram-negative bacteria, as demonstrated by the decline in pHint as well as cell membrane hyperpolarization. In conclusion, plant extracts are of great value as natural antimicrobials and can use safely as food preservatives.

Controlled Surface Modification of Polyamide 6.6 Fibres Using CaCl2/H2O/EtOH Solutions

Polyamide 6.6 is one of the most widely used polymers in the textile industry due to its durability; however, it has rather limited modification potential. In this work, the controlled surface modification of polyamide 6.6 fibres using the solvent system CaCl2/H2O/EtOH was studied. The effects of solvent composition (relative proportions of the three components) and treatment time on fibre properties were studied both in situ (with fibres in solvent) and ex situ (after the solvent was washed off). The fibres swell and/or dissolve in the solvent depending on its composition and the treatment time. We believe that the fibre⁻solvent interaction is through complex formation between the fibre carbonyl groups and the CaCl2. On washing, there is decomplexation and precipitation of the polymer. The treated fibres exhibit greater diameters and surface roughness, structural difference between an outer shell and an inner core is observable, and water retention is higher. The solvent system is more benign than current alternatives, and through suitable tailoring of the treatment conditions, e.g., composition and time, it may be used in the design of advanced materials for storage and release of active substances.

Development of active, nanoparticle, antimicrobial technologies for muscle-based packaging applications

Fresh and processed muscle-based foods are highly perishable food products and packaging plays a crucial role in providing containment so that the full effect of preservation can be achieved through the provision of shelf-life extension. Conventional packaging materials and systems have served the industry well, however, greater demands are being placed upon industrial packaging formats owing to the movement of muscle-based products to increasingly distant markets, as well as increased customer demands for longer product shelf-life and storage capability. Consequently, conventional packaging materials and systems will have to evolve to meet these challenges. This review presents some of the new strategies that have been developed by employing novel nanotechnological concepts which have demonstrated some promise in significantly extending the shelf-life of muscle-based foods by providing commercially-applicable, antimicrobially-active, smart packaging solutions. The primary focus of this paper is applied to subject aspects, such as; material chemistries employed, forming methods utilised, interactions of the packaging functionalities including nanomaterials employed with polymer substrates and how such materials ultimately affect microbes. In order that such materials become industrially feasible, it is important that safe, stable and commercially-viable packaging materials are shown to be producible and effective in order to gain public acceptance, legislative approval and industrial adoption.

Scale-Up Preparation and Characterization of Collagen/Sodium Alginate Blend Films

In an effort to produce scale-up of edible films, collagen-based films including different amounts of sodium alginate (CS) were prepared by casting method. Films were characterized based on their rheological, thermal, and mechanical properties, water vapor permeability (WVP), and oxygen permeability (OP). The microstructures were also evaluated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform-infrared spectroscopy (FTIR). Furthermore, the addition of sodium alginate effectively improved the viscosity and thermal stability, significantly increased TS, and decreased E and WVP (P<0.05), but with no obvious effect on OP (P>0.05). SEM and AFM showed homogeneous matrix, with no signs of phase separation in the blends. Overall, films (CS2) produced using collagen (g) : sodium alginate (g) = 10 : 2 showed suitable rheological property (apparent viscosity was 4.87 m Pa s−1) and better TS (26.49 Mpa), E (64.98%), WVP (1.79 × 10−10 g·cm−1·s−1·Pa−1), and OP (3.77 × 10−5 cm3·m−2·d−1·Pa−1).