Development of novel active polypropylene based packaging films containing different concentrations of sorbic acid

Effect of active antimicrobial films on quality parameters and shelf-life of fresh yufka dough

This research aimed to develop polypropylene (PP) antimicrobial films loaded with different concentrations of sorbic acid (SA) for packaging of fresh yufka dough. PP-SA at 6% showed improved mechanical, UV absorption, and moisture barrier properties. Also, the obtained films exhibited in vitro antibacterial and anti-mold properties. Moisture content and aw of packaged dough with different types of active films were not significantly changed upon storage period. Extended storage of dough layered with PP-SA films at concentrations 0-4% for 45 days led to significant decrease of pH from 5.75 in fresh dough to 5.05 in control (p < 0.05). Color attributes including yellowness and whiteness indices of dough were declined and increased, respectively as function of prolonged storage and increase in the concentration of SA. The growth of aerobic psychrotrophic bacteria and filamentous fungi were significantly retarded in yufka dough packaged with PP-SA6% film compared to that packaged with control as well as PP-SA2-4% films. Direct addition of SA into the bulk of dough was not effective in preservation of dough against the growth of bacteria and fungi. Application of antimicrobial preservatives in the composition of PP films could be beneficial in preserving fresh foods such as bakery products against spoilage microorganisms.

Preparation and Functionalization of Polymers with Antibacterial Properties-Review of the Recent Developments

The presence of antibiotic-resistant bacteria in our environment is a matter of growing concern. Consumption of contaminated drinking water or contaminated fruit or vegetables can provoke ailments and even diseases, mainly in the digestive system. In this work, we present the latest data on the ability to remove bacteria from potable water and wastewater. The article discusses the mechanisms of the antibacterial activity of polymers, consisting of the electrostatic interaction between bacterial cells and the surface of natural and synthetic polymers functionalized with metal cations (polydopamine modified with silver nanoparticles, starch modified with quaternary ammonium or halogenated benzene). The synergistic effect of polymers (N-alkylaminated chitosan, silver doped polyoxometalate, modified poly(aspartic acid)) with antibiotics has also been described, allowing for precise targeting of drugs to infected cells as a preventive measure against the excessive spread of antibiotics, leading to drug resistance among bacteria. Cationic polymers, polymers obtained from essential oils (EOs), or natural polymers modified with organic acids are promising materials in the removal of harmful bacteria. Antimicrobial polymers are successfully used as biocides due to their acceptable toxicity, low production costs, chemical stability, and high adsorption capacity thanks to multi-point attachment to microorganisms. New achievements in the field of polymer surface modification in order to impart antimicrobial properties were summarized.

A Review on Antimicrobial Packaging for Extending the Shelf Life of Food

Food packaging systems are continually impacted by the growing demand for minimally processed foods, changing eating habits, and food safety risks. Minimally processed foods are prone to the growth of harmful microbes, compromising quality and safety. As a result, the need for improved food shelf life and protection against foodborne diseases alongside consumer preference for minimally processed foods with no or lesser synthetic additives foster the development of innovative technologies such as antimicrobial packaging. It is a form of active packaging that can release antimicrobial substances to suppress the activities of specific microorganisms, thereby improving food quality and safety during long-term storage. However, antimicrobial packaging continues to be a very challenging technology. This study highlights antimicrobial packaging concepts, providing different antimicrobial substances used in food packaging. We review various types of antimicrobial systems. Emphasis is given to the effectiveness of antimicrobial packaging in various food applications, including fresh and minimally processed fruit and vegetables and meat and dairy products. For the development of antimicrobial packaging, several approaches have been used, including the use of antimicrobial sachets inside packaging, packaging films, and coatings incorporating active antimicrobial agents. Due to their antimicrobial activity and capacity to extend food shelf life, regulate or inhibit the growth of microorganisms and ultimately reduce the potential risk of health hazards, natural antimicrobial agents are gaining significant importance and attention in developing antimicrobial packaging systems. Selecting the best antimicrobial packaging system for a particular product depends on its nature, desired shelf life, storage requirements, and legal considerations. The current review is expected to contribute to research on the potential of antimicrobial packaging to extend the shelf life of food and also serves as a good reference for food innovation information.

Effect of Tea Polyphenols on the Melt Grafting of Glycidyl Methacrylate onto Polypropylene

It is considered to be one of the most effective strategies to prepare functionalized polypropylene (PP) materials via the melt grafting of polar monomers onto PP chains. However, the grafting efficiency of functional monomers is generally low. To achieve a high grafting efficiency, we explored the effect of tea polyphenols (C), which are good free radical scavengers, on the melt grafting of glycidyl methacrylate (GMA) onto PP chains initiated by dicumyl peroxide (DCP). Specifically, 0.5~3 wt% of tea polyphenols (C) were introduced to the PP/DCP/GMA melt blending system. The morphology, melt flow rate (MFR), thermal and mechanical properties of tea polyphenols (C) incorporated PP/DCP/GMA blends were investigated systematically. The results showed that the proper amount of tea polyphenols (C) (0.5~2 wt%) promoted the grafting of GMA. Unexpectedly, the PP backbone suffered from more severe degradation with the addition of tea polyphenols (C). The phenomena were ascribed to the reaction between phenolic hydroxyl groups of tea polyphenols (C) and epoxy groups of grafted GMA, which was revealed by the FTIR results. In addition, according to DSC and the tensile test, the co-grafting of GMA and tea polyphenols (C) improved the crystallization ability, yield strength and Young's modulus of the PP matrix.

Antibacterial, Antifungal and Antiviral Polymeric Food Packaging in Post-COVID-19 Era

Consumers are now more concerned about food safety and hygiene following the COVID-19 pandemic. Antimicrobial packaging has attracted increased interest by reducing contamination of food surfaces to deliver quality and safe food while maintaining shelf life. Active packaging materials to reduce contamination or inhibit viral activity in packaged foods and on packaging surfaces are mostly prepared using solvent casting, but very few materials demonstrate antiviral activity on foods of animal origin, which are important in the human diet. Incorporation of silver nanoparticles, essential oils and natural plant extracts as antimicrobial agents in/on polymeric matrices provides improved antifungal, antibacterial and antiviral properties. This paper reviews recent developments in antifungal, antibacterial and antiviral packaging incorporating natural or synthetic compounds using preparation methods including extrusion, solvent casting and surface modification treatment for surface coating and their applications in several foods (i.e., bakery products, fruits and vegetables, meat and meat products, fish and seafood and milk and dairy foods). Findings showed that antimicrobial material as films, coated films, coating and pouches exhibited efficient antimicrobial activity in vitro but lower activity in real food systems. Antimicrobial activity depends on (i) polar or non-polar food components, (ii) interactions between antimicrobial compounds and the polymer materials and (iii) interactions between environmental conditions and active films (i.e., relative humidity, oxygen and water vapor permeability and temperature) that impact the migration or diffusion of active compounds in foods. Knowledge gained from the plethora of existing studies on antimicrobial polymers can be effectively utilized to develop multifunctional antimicrobial materials that can protect food products and packaging surfaces from SARS-CoV-2 contamination.

Improving carboxymethyl cellulose edible coating using ZnO nanoparticles from irradiated Alternaria tenuissima

In this paper, gamma-irradiation was successfully used to intensify the yield of Zinc oxide nanoparticles (ZnONPs) produced by the fungus Alternariatenuissima as a sustainable and green process. The obtained data showed that 500 Gy of gamma-irradiation increased ZnONPs’ yield to approximately four-fold. The synthesized ZnONPs were then exploited to develop active Carboxymethyl Cellulose films by casting method at two different concentration of ZnONPs 0.5% and 1.0%. The physicochemical, mechanical, antioxidant, and antimicrobial properties of the prepared films were evaluated. The incorporation of ZnONPs in the Carboxymethyl Cellulose films had significantly decreased solubility (from 78.31% to 66.04% and 59.72%), water vapor permeability (from 0.475 g m⁻² to 0.093 g m⁻² and 0.026 g m⁻²), and oxygen transfer rate (from 24.7 × 10^–2 to 2.3 × 10^–2 and 1.8 × 10^–2) of the respective prepared films. Meanwhile, tensile strength (from 183.2 MPa to 203.34 MPa and 235.94 MPa), elongation (from 13.0% to 62.5% and 83.7%), and Yang's modulus (from 325.344 to 1410.0 and 1814.96 MPa) of these films were increased. Moreover, the antioxidant and antimicrobial activities against several human and plant pathogens the prepared of Carboxymethyl Cellulose-ZnONPs films were significantly increased. In conclusion, the prepared Carboxymethyl Cellulose-ZnONPs films showed enhanced activities in comparison with Carboxymethyl Cellulose film without NPs. With these advantages, the fabricated Carboxymethyl Cellulose-ZnONPs films in this study could be effectively utilized as protective edible coating films of food products.

Application of innovative packaging technologies to manage fungi and mycotoxin contamination in agricultural products: Current status, challenges, and perspectives

The consumer demand for safe, "healthy," and premium foods, preferably with an extended shelf-life; demand for easy packaging; and choice for more sustainable food packaging have contributed to the development of novel packaging technologies. The application of adequate packaging materials has recently become a major post-harvest challenge concerning the control of fungi and mycotoxin. This review will describe the current antifungal packaging technology involved to prevent the contamination of fungi and mycotoxin, along with the characteristics and mechanism of action in food products. Antifungal packaging has incredible potential in the food packaging sector. The most suitable approach for the safe storage of agricultural produce for farmers is the hermetic packaging technology, which maintains quality while providing a good barrier against fungi and mycotoxin. Furthermore, active antifungal packaging is a viable method for incorporating antifungal agents against pathogenic fungi. Essential oils and organic acid have received more scientific attention due to their increased efficacy against mold growth. Polypeptides, chitosan, and natamycin incorporated in active packaging significantly reduced fungi. Even though nanotechnological advancements in antifungal packaging are promising, safety and regulation issues remain significant concerns.

Microencapsulation of curcumin by spray drying: Characterization and fortification of milk

Curcumin, the major bioactive component of turmeric (Curcuma longa), was microencapsulated by spray drying in the matrix of HI-CAP 100 (resistant starch)/ maltodextrin and whey protein isolate to improve its oral bioavailability and solubility. Taguchi orthogonal array design (L₁₈) was used to optimize the spray drying conditions. The optimal conditions for microencapsulation were inlet drying air temperature of 185 °C, feed rate of 6 mL/min and HI-CAP 100 as wall material. The moisture content, encapsulation efficiency and bulk density at these conditions were 4.65%, 82.42% and 358.40 kg/m³, respectively. The spray-dried microcapsules were spherical-shaped with folds and vacuoles. The yellowness index and a^* value of curcumin decreased after microencapsulation. FTIR spectroscopy indicated that the curcumin after microencapsulation presumably retained its chemical structure. DSC thermograms confirmed that the microcapsules were heat stable up to 200 °C. The microcapsules had better heat stability and sustained in-vitro release as compared to that of pure curcumin. The DPPH free radical scavenging activity of curcumin was 61.43%, which was largely unaffected after microencapsulation. Fortification of milk with HI-CAP 100-based microcapsules at the selected dose had no adverse effect on organoleptic properties as compared to normal milk.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05142-0.

Microscopic and Structural Studies of an Antimicrobial Polymer Film Modified with a Natural Filler Based on Triterpenoids

The aspects of component visualization of the antimicrobial triterpenoids (betulin) additive, both on the surface and in the bulk of the polymer, constituting food film packaging, are considered. This paper presents new knowledge about the morphology and surface structure of modified films using three independent methodological approaches: optical microscopy; a histological method adapted to packaging materials; and a method of attenuated total internal reflection (ATR) spectroscopy in the infrared region with Fourier transform. The use of these methods shows the betulin granules, individual or forming chains. To visualize the antimicrobial additive in the polymer bulk, a modified histological method adapted for film materials and attenuated total internal reflection (ATR) spectroscopy in the infrared region were used with Fourier transform using a Lumos Bruker microscope (Germany) (ATR crystal based on germanium). Sample sections were analyzed using Leica 818 blades at an angle of 45 degrees. The histological method consists of the study of a biological object thin section, in the transmitted light of a microscope, stained with contrast dyes to reveal its structures, and placed on a glass slide. In the method modified for the present study, instead of a biological one, a synthetic object was used, namely the developed film materials with the addition of natural organic origin. Individual granules are about 2 µm long; chains can be up to 10 µm long. The thickness of the granules ranged from 1 to 1.5 microns. It can be seen that the depth distribution of granules in the film from the inner surface to the outer one is rather uniform. Spectroscopic studies using the method of automatic ATR mapping in the region of 880 cm⁻¹ made it possible to evaluate the distribution of an antimicrobial additive based on triterpenoids on the surface and in the polymer bulk.

A Review of Nonbiodegradable and Biodegradable Composites for Food Packaging Application

The dependency on nonbiodegradable-based food packaging, increase in population growth, and persistent environmental problems are some of the driving forces in considering the development of biodegradable food packaging. This effort of green packaging has the potential to solve issues on plastic wastes through the combination of biodegradable composite-based food packaging with plant extracts, nanomaterials, or other types of polymer. Modified biodegradable materials have provided numerous alternatives for producing green packaging with mechanical strength, thermal stability, and barrier performance that are comparable to the conventional food packaging. To the best of our knowledge, the performance of nonbiodegradable and biodegradable composites as food packaging in terms of the above properties has not yet been reviewed. In this context, the capability of biodegradable polymers to substitute the nonbiodegradable polymers was emphasized to enhance the packaging biodegradation while retaining the mechanical strength, thermal stability, barrier properties, and antioxidant and antimicrobial or antibacterial activity. These are the ultimate goal in the food industry. This review will impart useful information on the properties of food packaging developed from different polymers and future outlook toward the development of green food packaging.

Quality Characteristics of Semi-Moist Apricot-Cornflakes: Effect of Different Composite Coating Application and Storage Time

The effect of different composite coatings on quality of semi-moist apricot cubes mixed with cornflakes was investigated during 180 days of storage. The apricot cubes were osmotically dehydrated (OD) and coated before hot-air drying (HAD) at 60 °C. Chitosan-bees wax (CBW) and whey protein isolate-bees wax-oleic acid (WPI-BW-OA) coatings were applied after HAD and the samples were added to cornflakes. Application of OD and pectin-ascorbic acid (Pec-AA) coating (prior to HAD) and WPI-BW-OA coating (after HAD) led to significant retention of total phenol compounds, β-carotene and antioxidant activity in apricot cubes compared to uncoated and CBW-coated samples. WPI-BW-OA-coated samples gave significantly higher L* values (lighter color) and b* values (more creamy or yellowish color) and lower a* values (less reddish color) and browning values than control followed by CBW-coated apricots at any time of storage (p < 0.05). The rate of apricot moisture loss and cornflakes moisture gain was higher in uncoated apricot cubes, followed by CBW- and WPI-BW-OA-coated samples. Application of WPI-BW-OA coating was effective in retaining the crispness measured by lower firmness (Fmax) values in cornflakes upon storage. Based on the obtained results, WPI-BW-OA coating allowed effectively preserving the quality characteristics of semi-moist apricot cubes and cornflakes components in the mixed state.

Active Polypropylene-Based Films Incorporating Combined Antioxidants and Antimicrobials: Preparation and Characterization

Development of polypropylene (PP) films incorporating antioxidant-antimicrobial agents can inhibit microbial growth and reduce undesirable deteriorating reactions and can preserve the quality of food. This study was aimed to use a combination of sorbic acid (SA), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) to provide a synergistic effect at their reduced concentrations. A Combination of the additives was more effective in enhancing mechanical properties compared to their single state in film composition. The PP-2%SA-3%BHA film (T₃) had the highest tensile strength (17.9 MPa) and the lowest elongation at break (7.1%) than other films. The fourier-transform infrared (FTIR) proposed physical mixing of active additives within PP-matrix. Scanning electron microscopy showed uniform dispersion of the additives in PP-2%SA-1%BHT-1%BHA film (T₄) compared to others. BHT containing films decreased the storage and loss moduli leading to weakening of film viscoelastic behaviour and reducing film melting point. The prepared active films showed higher antioxidant activity than control PP-film following an order of T₄ > T₂ > T₃ corresponding to DPPH radical scavenging values of 89.1, 83.4 and 79.1%, respectively. All active films inhibited gram-negative and gram-positive bacteria growth. The results of this study indicated that the prepared active films possess desirable mechanical, thermal, antioxidant and antimicrobial properties enabling their use in food packaging.

A critical review on intelligent and active packaging in the food industry: Research and development

The emergence of many new food products on the market with need of consumers to constantly monitor their quality until consuming, in addition to the necessity for reducing food corruption during preservation time, have led to the development of some modern packaging technologies such as intelligent packaging (IP) and active packaging (AP). The benefits of IP are detecting defects, quality monitoring and tracking the packaged food products to control the storage conditions from the production stage to the consumption stage by using various sensors and indicators such as time-temperature indicators (TTIs), gas indicators, humidity sensors, optical, calorimetric and electrochemical biosensors. While, AP helps to increase the shelf-life of products by using absorbing and diffusion systems for various materials like carbon dioxide, oxygen, and ethanol. However, there are some important issues over these emerging technologies including cost, marketability, consumer acceptance, safety and organoleptic quality of the food and emphatically environmental safety concerns. Therefore, future researches should be conducted to solve these problems and to prompt applications of IP and AP in the food industry. This paper reviews the latest innovations in these advanced packaging technologies and their applications in food industry. The IP systems namely indicators, barcoding techniques, radio frequency identification systems, sensors and biosensor are reviewed and then the latest innovations in AP methods including scavengers, diffusion systems and antimicrobial packaging are reviewed in detail.

Impact of high-pressure treatment on casein micelles, whey proteins, fat globules and enzymes activity in dairy products: a review

The quality and safety of food products are the two factors that most influence the demands made by consumers. Contractual food sterilization and preservation methods often result in unfavorable changes in functional properties of foods. High-pressure processing (HPP) (50-1000 MPa) is a non-thermal preservation technique, which can effectively reduce the activity of spoilage and pathogenic microorganisms with minimal impact on the functional and nutritional properties of food. Comprehensive inquires have disclosed the potential profits of HPP as an alternative to heat treatments by affecting the structure of milk components, particularly proteins and fats. The present paper aims to investigate the effects of HPP on milk components including fats, casein, whey proteins, enzymes, and minerals, as well as on the industrial production of milk and dairy products including cheese, yogurt, ice cream, butter, cream, and probiotic dairy products. HPP allows to extend shelf life of products without the use of additives, meeting current consumer demands. The assurance of microbial safety and the production of food products with minimal changes in quality characteristics (organoleptic, nutritional, and rheological properties) are among its main effects. In addition, the nutritional value of HPP-treated dairy products is also preserved.

Sandwich panel biocomposite of thermoplastic corn starch and bacterial cellulose

Inadequate disposition and long period for degradation of Petroleum-derived polymers promote damages in the environment, which could be minimized by the use of biodegradable polymers such as starch and cellulose. Films of thermoplastic corn starch (TPS) and bacterial cellulose (BC) were used to produce sandwich panel biocomposite. RXD, SEM and FTIR were used to verify the transformation of TPS from native corn starch. TPS/BC is flexible and transparent, but it is less transparent that TPS and BC due to its multilayer format. TPS/BC presented similar thermal events to TPS and BC samples and thermal stability similar to TPS. The FTIR spectrum of the TPS/BC showed bands observed in the BC and TPS spectra. BC, TPS and TPS/BC showed faster water absorption in the initial stage reaching a stability at about 50 h and presenting Fickian behavior. TPS/BC showed lower water absorption and a good adhesion between the phases observed by SEM images, which can be associated to hydrogen interactions in the interface improving mechanical properties. TPS/BC showed an increase of about 3.6 times in the tensile strength compared to TPS, indicating that BC is a good reinforcement for TPS.

Properties and Application of Multifunctional Composite Polypropylene-Based Films Incorporating a Combination of BHT, BHA and Sorbic Acid in Extending Donut Shelf-Life

To extend the shelf-life of packaged donut without the addition of preservative, polypropylene-based active composite films loaded with a combination of sorbic acid, BHA and BHT were prepared by the extrusion moulding method: T1 (Control-pure PP-film), T2 (PP-BHT1%-SA2%), T3 (PP-BHA3%-SA2%) and T4 (PP-BHT1%-BHA1%-SA2%). The incorporation of active additives enhanced water vapour permeability (WVP) and increased oxygen permeability of films. Active films had higher antioxidant activity than pure PP in the order T4 > T2 > T3 (89.11, 83.40 and 79.16%). In vitro examinations demonstrated a significant antibacterial effect on Escherichia coli and S. aureus growth. Overall migration was not significantly different for watery food simulants, while in acidic and fatty foods increased it significantly. The effect of the active films on the fried and packaged donut samples showed significantly higher moisture contents and peroxide values, while acidity was lower. T2 film is proposed due to the preservation of the intrinsic properties of the film, increasing the storage period up to 25 to 50 days.

Migration analysis, antioxidant, and mechanical characterization of polypropylene-based active food packaging films loaded with BHA, BHT, and TBHQ

Polypropylene (PP) based active composite films were prepared by adding butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylated hydroquinone (TBHQ) antioxidants using the extrusion molding process. All concentrations of BHT, 2% to 3% BHA, and 3% TBHQ significantly increased the tensile strength (TS) of the composite films compared with control films. Increasing antioxidant concentration decreased TS values for BHT films, whereas an opposite trend was observed for BHA and TBHQ films. BHA at < 2%, BHT at > 2%, and TBHQ at all added concentrations significantly reduced elongation at break (E_b ) of the composite films compared to control films. Water vapor permeability (WVP) of 1% BHT film was not significantly different from control. However, other antioxidants especially at increased concentrations significantly increased WVP values. TBHQ films with 300% to 662% increase had the highest WVP and BHT films with 5% to 81% increase had the lowest WVP among composite films. All three antioxidants had a negative effect on the transparency of the films; however the effect of BHA at higher concentrations was greater. The antioxidants did not change the color attributes of the films. Films containing all antioxidants showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, which increased with increase in their concentration, especially for those containing 3 wt.% BHT and TBHQ. Overall, incorporating BHA and BHT into a PP matrix improved mechanical, barrier, antioxidant properties, and film appearance and consequently were proposed for the development of antioxidant active PP films. TBHQ film is not recommended for food packaging because of its weak mechanical properties (lower E_b and TS values, higher WVP, and greater migration).

Development of Antibacterial Carboxymethyl Cellulose-Based Nanobiocomposite Films Containing Various Metallic Nanoparticles for Food Packaging Applications

In this study, silver (Ag), zinc oxide (ZnO), and copper oxide (CuO) metallic nanoparticles were used in preparation of carboxymethyl cellulose (CMC) nanobiocomposite films. Scanning electron microscopy (SEM), X-ray diffraction (EDXA), water vapor permeability (WVP), ultraviolet and visible light (UV-Vis) spectroscopy, and mechanical and microbial tests were used to determine the characteristics of the obtained active films. SEM results showed that the CMC nanobiocomposite films had roughness deflection levels and the EDXA test confirmed the presence of Ag, ZnO, and Cuo nanoparticles in the biopolymer tissue. UV-Vis spectroscopy confirmed that with addition of metallic nanoparticles to the pure CMC film, absorption rate increased and WVP decreased. In the mechanical tests, addition of nanoparticles also increased the tensile strength of the films, and the nanobiocomposite films exhibited higher resistance compared to the pure CMC film. Films incorporating metallic nanoparticles showed antibacterial properties against Escherichia coli and Staphylococcus aureus growth. Thus, nanobiocomposite films can be used as active packaging films and could increase the shelf-life of the food.