Development of new active packaging films containing bioactive nanocomposites

Enhancing mechanical and blocking properties of gelatin films using zein-quercetin nanoparticle and applications for strawberry preservation

New gelatin films incorporated with zein-quercetin nanoparticles (GA/ZQNPs) were developed. The GA/ZQNP films had improved tensile strength, water vapor and oxygen barrier capabilities, hydrophobicity, UV blocking feature, antioxidant activities and antimicrobial properties, which varied with various contents of ZQNPs. Notably, the GA/ZQNP0.1-10 films exhibited enhanced tensile stress value around 3.2 MPa and strain of 142 %, a 78.4 % decrease in water vapor permeability, a 76.9 % decrease in oxygen permeability, the highest water contact angle at 112.0 ± 0.6°, an improved DPPH∙ scavenging rate of 64.9 ± 0.7 %, excellent UV blocking properties and antimicrobial properties. The GA/ZQNP films were further applied for strawberries packaging to assess their preservation capabilities under ambient conditions. The results showed that GA/ZQNP0.1-10 nanocomposite films efficiently maintained the best nutrient quality and acceptable appearance of strawberries compared with untreated strawberries, prolonging the shelflife of strawberries to approximately 8 days. These findings suggested promising applications for these new functional films in fruit packaging.

In Situ Reactive Extrusion of LDPE Films with Methacrylated Pyrogallol for Antimicrobial and Antioxidant Active Packaging

Reactive extrusion is a scalable technology for active packaging that promotes food quality and safety. This study investigated the grafting of a methacrylate pyrogallol (PGMC) active agent onto low-density polyethylene (LDPE) through an in situ reactive extrusion process with varying concentrations of PGMC (1, 3, and 5 wt.%). The addition of 5% PGMC increased the tensile strength of pure LDPE from 17.94 MPa to 22.04 MPa. The thermal stability of the samples remained unaffected after PGMC addition, and the grafting process did not interfere with the barrier properties of the LDPE films. Furthermore, 5% PGMC exhibited significant antimicrobial properties, showing 100% and 99.11% reductions in the microbial activity of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), respectively. Moreover, the LDPE film with 5% PGMC demonstrated the highest DPPH scavenging effect, reaching up to 85.71%. Therefore, LDPE-g-PGMC films (5%), with antimicrobial and antioxidant properties, have potential applications in non-migratory active packaging.

Migration of silver nanoparticles from plastic materials, with antimicrobial action, destined for food contact

Five materials with antimicrobial function, by adding silver, were investigated to evaluate total silver concentration in the polymers and migration of silver nanoparticles from the materials in contact with food. The migration test was carried out by contacting plastic material with food simulant. Migration concentrations and average silver particle sizes were determined by mass spectrometry with inductively coupled plasma, performed in single particle mode (spICP-MS). Additionally, silver particles size and shape were characterized by scanning electron microscopy (SEM) with chemical identification by energy-dispersive X-ray spectroscopy (EDS). Most of samples showed detectable total silver concentrations and all samples showed migration of silver nanoparticles, with concentrations found between 0.00433 and 1.35 ng kg-1. Indeed, the migration study indicated the presence of silver nanoparticles in all food simulants, with sizes bellow 95 nm. The average particle size determined for acetic acid was greater than that observed in the other simulants. In the images obtained by SEM/EDS also confirmed the presence of spherical silver nanoparticles, between 17 and 80 nm. The findings reported herein will aid the health area concerning of human health risk assessments, aiming at regulating this type of material from a food safety point of view.

What is the role of active packaging in the future of food sustainability? A systematic review

Nowadays, the strong increase in products consumption, the purchase of products on online platforms as well as the requirements for greater safety and food protection are a concern for food and packaging industries. Active packaging brings huge advances in the extension of product shelf-life and food degradation and losses reduction. This systematic work aims to collect and evaluate all existing strategies and technologies of active packaging that can be applied in food products, with a global view of new possibilities for food preservation. Oxygen scavengers, carbon dioxide emitters/absorbers, ethylene scavengers, antimicrobial and antioxidant active packaging, and other active systems and technologies are summarized including the products commercially available and the respective mechanisms of action. © 2022 Society of Chemical Industry.

Effect of Nano-TiO2 Composite on the Fertilization and Fruit-Setting of Litchi

Titanium dioxide nanoparticles (nTiO₂) are widely used as fertilizers in agricultural production because they promote photosynthesis and strong adhesion. Low pollination and fertilization due to rainy weather during the litchi plant's flowering phase result in poor fruit quality and output. nTiO₂ would affect litchi during the flowering and fruiting stages. This study considers how nTiO₂ affects litchi's fruit quality and pollen viability during the flowering stage. The effects of nTiO₂ treatment on pollen vigor, yield, and fruit quality were investigated. nTiO₂ effectively improved the pollen germination rate and pollen tube length of litchi male flowers. The germination rate reached 22.31 ± 1.70%, and the pollen tube reached 237.66 μm in the 450 mg/L reagent-treated group. Spraying with 150 mg/L of nTiO₂ increased the germination rate of pollen by 2.67% and 3.67% for two types of male flowers (M1 and M2) of anthesis, respectively. After nTiO₂ spraying, the fruit set rates of 'Guiwei' and 'Nomici' were 46.68% and 30.33%, respectively, higher than those of the boric acid treatment group and the control group. The edibility rate, titration calculation, and vitamin C of nTiO₂ treatment were significantly higher than those of the control. The nTiO₂-treated litchi fruit was more vividly colored. Meanwhile, the adhesion of nTiO₂ to leaves was effectively optimized by using ATP and BCS to form nTiO₂ carriers and configuring nTiO₂ complex reagents. These results set the foundation for future applications of titanium dioxide nanoparticles as fertilizers for agriculture and guide their application to flowers and fruits.

Active Flexible Films for Food Packaging: A Review

Active food packaging is a dynamic area where the scientific community and industry have been trying to find new strategies to produce innovative packaging that is economically viable and compatible with conventional production processes. The materials used to develop active packaging can be organized into scavenging and emitting materials, and based on organic and inorganic materials. However, the incorporation of these materials in polymer-based flexible packaging is not always straightforward. The challenges to be faced are mainly related to active agents' sensitivity to high temperatures or difficulties in dispersing them in the high viscosity polymer matrix. This review provides an overview of methodologies and processes used in the production of active packaging, particularly for the production of active flexible films at the industrial level. The direct incorporation of active agents in polymer films is presented, focusing on the processing conditions and their effect on the active agent, and final application of the packaging material. Moreover, the incorporation of active agents by coating technologies and supercritical impregnation are presented. Finally, the use of carriers to help the incorporation of active agents and several methodologies is discussed. This review aims to guide academic and industrial researchers in the development of active flexible packaging, namely in the selection of the materials, methodologies, and process conditions.

Physical and functional properties of fish gelatin-based film incorporated with mangrove extracts

Background

The fishery processing industry produces a remarkable number of by-products daily. Fish skin accounts for one of the significant wastes produced. Fish skin, however, can be subjected to extraction to yield gelatine and used as the primary raw material for edible film production. To increase the functionality of edible films, bioactive compounds can be incorporated into packaging. Mangroves produce potential bioactive compounds that are suitable as additional agents for active packaging. This study aimed to create a fish gelatine-based edible film enriched with mangrove extracts and to observe its mechanical and biological properties.

Methods

Two mangrove species (Bruguiera gymnorhiza and Sonneratia alba) with four extract concentrations (control, 0.05%, 0.15%, 0.25%, and 0.35%) were used to enrich edible films. The elongation, water vapour transmission, thickness, tensile strength, moisture content, antioxidant and antibacterial properties of the resulting packaging were analysed.

Results

The results showed that the mangrove species and extract concentration significantly affected (p < 0.05) the physical properties of the treated films such as elongation (16.89-19.38%), water vapour transmission (13.31-13.59 g/m²), and active packaging-antioxidant activities (12.36%-60.98%). The thickness, tensile strength, and water content were not significantly affected. Potent antioxidant activity and relatively weak antimicrobial activity of this active gelatine packaging were observed.

Preparation and Characterization of Bio-Nanocomposites Film of Chitosan and Montmorillonite Incorporated with Ginger Essential Oil and Its Application in Chilled Beef Preservation

In this study, bio-nanocomposite films containing different proportions of ginger essential oil (GEO), chitosan (Ch), and montmorillonite (MMT) were prepared and characterized, and the antibacterial effect of bio-nanocomposite films on chilled beef was evaluated. Fourier transform infrared analysis showed a series of intense interactions among the components of the bio-nanocomposite films. The infiltration of GEO increased the thickness of the film, reduced the tensile strength of the film, and increased the percentage of breaking elongation and the water vapor permeability. The migration of phenols in the films began to increase exponentially and reached equilibrium at about 48 h. The bio-nanocomposite films (Ch +0.5% GEO group, and Ch + MMT + 0.5% GEO group) effectively delayed the rise of pH, hue angle, and moisture values of chilled beef with time and slowed down the lipid oxidation and the growth of surface microorganisms on chilled beef. Altogether, the prepared biological nanocomposites can be used as promising materials to replace commercial and non-degradable plastic films.

Sushi processing: microbiological hazards and the use of emerging technologies

Sushi meal has been adapting to different countries and traditions ever since it was invented. Recently there is a growing popularity of ready-to-eat sushi meals, with new sushi production plants emerging in many countries. This relatively new sushi industry is facing many challenges, one of which is the microbiological hazard related to sushi consumption. The aim of this review was to summarize the most significant aspects with regard to microbiological quality of sushi, reported cases of sushi-related poisoning, as well as the potential of modern innovative and emerging technologies to inhibit microbiological growth. Although there is a limited amount of studies in relation to sushi shelf-life extension, the existing data shows potential of using novel minimal processing technologies to improve the shelf-life and quality of sushi meals. Those technologies include the use of cold plasma, plasma activated water and electrolyzed water, as well as the use of innovative packaging and edible coatings. Based on the collected data, the possible microbiological hazards in the production process of sushi, with possible use of emerging technologies to reduce or eliminate those risks, are also emphasized.

Natural Phenolic Compounds for the Control of Oxidation, Bacterial Spoilage, and Foodborne Pathogens in Meat

Alternative technologies for long-term preservation, quality assurance, and safety of meat are continuously pursued by the food industry to satisfy the demands of modern consumers for nutritious and healthy meat-based products. Naturally occurring phenolic compounds are considered promising substances by the meat industry for their antioxidant and antimicrobial properties, while consumers seem to embrace them for their claimed health benefits. Despite the numerous in vitro and in situ studies demonstrating their beneficial effects against meat oxidation, spoilage, and foodborne pathogens, wide application and commercialization has not been yet achieved. Major obstacles are still the scarcity of legislative framework, the large variety of meat-based products and targeted pathogens, the limited number of case-specific application protocols and the questionable universal efficiency of the applied ones. The objectives of the present review are i) to summarize the current knowledge about the applications of naturally occurring phenols in meat and meat-based products, emphasizing the mechanisms, determinants, and spectrum of their antioxidant and antimicrobial activity; ii) to present state-of-the-art technologies utilized for the application of phenolic compounds in meat systems; and iii) to discuss relevant regulation, limitations, perspectives, and future challenges for their mass industrial use.

Na-Montmorillonite vs. Organically Modified Montmorillonite as Essential Oil Nanocarriers for Melt-Extruded Low-Density Poly-Ethylene Nanocomposite Active Packaging Films with a Controllable and Long-Life Antioxidant Activity

Nowadays, active packaging is becoming significant for the extension of the shelf life of food products via the incorporation of raw nanomaterials such as nanoclays and bioactive compounds such as essential oils (EO). This study aims to study the performance of the sodium montmorillonite (NaMt) and organically modified montmorillonite (OrgMt) as thyme (TO), oregano (OO), and basil (BO) essential oil (EO) control release nanocarriers in low-density poly-ethylene (LDPE) active films. NaMt and OrgMt nanofillers are modified with low (20 wt.%), medium (40 wt.%), and high (80 wt.%) nominal contents of TO, OO, and BO. The novel active packaging films were tested using the X-ray diffraction method (XRD), tensile, water, and oxygen barrier properties, and antioxidant activity tests. For the two most active packaging films, the lipid oxidation of chicken breast fillets estimated by the thiobarbituric-acid-reacting substances (TBARS) method. Overall study shows that both NaMtEO-based and OrgMt-based films exhibited controllable and sustained antioxidant activity. All films retained up to 50-70% of their antioxidant activity after six months of incubation. OrgMtEO-based LDPE films showed more significance applied as active packaging films than NaMtEO-based LDPE films because of their highest tensile and barrier properties.

Development of New Multilayer Active Packaging Films with Controlled Release Property Based on Polypropylene/Poly(Vinyl Alcohol)/Polypropylene Incorporated with Tea Polyphenols

The polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films with controlled release property were developed, of which the intermediate PVA layer was incorporated with 4% (w/w) tea polyphenols (TP) and the microporous PP films with different pore size were used as the internal controlled release layer. The SEM results showed that each layer of these films was agglutinated tightly. With increasing pore size from 171.05 to 684.03 µm, there were little effect on the films' color and opacity, the tensile strength (TS) and elongation at break (EAB) decreased slightly, the gas barrier (O₂ and water vapor) property of the film reduced faintly, the time of achieving the release equilibrium in 50% ethanol decreased from 75 hours to 30 hours. The diffusion coefficient for the films increased with the increase of pore size, from 2.06 × 10^-11 cm² /s to 8.06 × 10^-11 cm² /s, suggesting that the release rate of TP increased as the pore size increased. The results were indicated that its release rate could be controlled by adjusting the size of pore. The films also exhibited different antioxidant activities due to their different release profiles of TP. It showed promise for developing the controlled release active packaging film based on this concept. PRACTICAL APPLICATION: Controlled release packaging is propitious to extension of food shelf life. The microporous polypropylene films with different pore size used as the internal layer of polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films was proved that the release rate of tea polyphenols in the intermediate PVA layer released from the films into the food simulant can be controlled by adjusting the size of pore in this study. It showed a good prospect for using microporous or perforation-mediated film as the internal layer of multilayer film to develop the controlled release active packaging film for food packaging.

Sustainable control strategies for plant protection and food packaging sectors by natural substances and novel nanotechnological approaches

An overview is provided of the current technological strategies (also at the nanoscale level) recently involved in plant and/or food protection. In addition, the potential use of natural and sustainable substances, instead of traditional synthesized molecules or chemical-based compounds, is addressed both with respect to packaging systems and novel pesticide formulations. In this context, nanotechnological approaches represent promising strategies for the entire agriculture industry chain, from the field to consumers. Traditional plant protection strategies are often insufficient and the application of chemical-based pesticides has negative effects on animals, humans and the environment. Novel greener tools could represent efficient alternatives for the management of plant diseases using promising strategies; the use of nanotechnologies allows the promotion of the more efficient assembly and subsequent release of environmentally sustainable active principles, limiting the use of chemicals in terms of economic losses. At the same time, new sustainable, antimicrobial and antioxidant systems have been rapidly promoted and investigated in the food packaging sector as a valid eco-friendly possibility for improving the safety and quality of food products and reducing and/or limiting the environmental impact with respect to traditional materials. Together, the scientific community and the growing interest of consumers have promoted the development of new edible and eco-friendly packaging that reduces waste and any environmental impact. In this context, the aim is to provide evidence of the usefulness of strategies aiming to limit agrochemicals, as well as the potential of nanomaterials, in sustainable plant and food protection for agriculture management and the packaging sector. © 2018 Society of Chemical Industry.

Phenolic Compounds as Nutraceuticals or Functional Food Ingredients

BACKGROUND

Nowadays, the functional foods represent one the most promising, interesting and innovative areas in the food industry. Various components are being added to foods in order to render them functional.

METHODS

One example of these components are plant naturally occurring phenolic compounds, which are associated with a high antioxidant capacity and thus with benefits in relation to human health.

RESULTS

However, despite the huge number of scientific studies and patents on this topic and their natural presence in foods, namely in the ones from plant origin, there are still few marketable products enriched with these compounds. The commercialization of this type of functional products needs to go through various regulations, proving that they are safe and present the ascribed health benefits, conquering the target audience. In this review the growing interest of industry and consumers' appetence for functional foods and nutraceuticals is highlighted, focusing especially on phenolic compounds.

CONCLUSION

Although several published works show the multitude of bioactive properties of these compounds, ensuring their use as bioactive ingredients in food, they present inherent stability issues needing to be solved. However, considerable research is presently ongoing to overcome this problem, making viable the development of new products to be launched in the market.

Gelatine-Based Antioxidant Packaging Containing Caesalpinia decapetala and Tara as a Coating for Ground Beef Patties

The development of antioxidant-active packaging has numerous advantages, such as the reduction of synthetic additives in food, the reduction of plastic waste and food protection against oxidation reactions. Different concentrations of extracts of the plants Caesalpinia decapetala (CD) and Caesalpinia spinosa "Tara" (CS) were incorporated into gelatine films as natural antioxidants. The physical, mechanical and antioxidant properties of these films were studied. Films containing plant extracts at a high concentration had lower tensile strength with higher elongation at break points, compared to the control film (p < 0.05). Films exhibited antioxidant activity in the oxygen radical absorbance capacity (ORAC) and Trolox equivalence antioxidant capacity (TEAC) assays when added at 0.2%. The application of gelatine film containing CD and CS was found to be effective in delaying lipid oxidation and deterioration of beef patty quality during storage. Therefore, the films prepared in this study offered an alternative edible coating for the preservation of fresh food.

Eggshell and Bacterial Cellulose Composite Membrane as Absorbent Material in Active Packaging

Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging.