scholarly journals Fabrication of PVA polymer films with improved antibacterial activity by fine-tuning via organic acids for food packaging applications

2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Sanjeevamuthu Suganthi ◽  
Shanmugam Vignesh ◽  
Jeyaperumal Kalyana Sundar ◽  
Vairamuthu Raj
Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 624
Author(s):  
Laima Česonienė ◽  
Juozas Labokas ◽  
Ina Jasutienė ◽  
Antanas Šarkinas ◽  
Vilma Kaškonienė ◽  
...  

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1249 ◽  
Author(s):  
Denis Mihaela Panaitescu ◽  
Eusebiu Rosini Ionita ◽  
Cristian-Andi Nicolae ◽  
Augusta Raluca Gabor ◽  
Maria Daniela Ionita ◽  
...  

In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to important changes in the thermal and mechanical behavior of PHB‒BC nanocomposite as well as in the surface structure and morphology. Strong chemical bonding of the metal nanoparticles on PHB surface following ZnO plasma coating was highlighted by infrared spectroscopy. Moreover, the presence of a continuous layer of self-aggregated ZnO nanoparticles was demonstrated by scanning electron microscopy, ZnO plasma treatment completely inhibiting growth of Staphylococcus aureus. A plasma-treated PHB‒BC nanocomposite is proposed as a green solution for the food packaging industry.


2021 ◽  
Author(s):  
Nasser H. Mohammad ◽  
gamal Mohamed elsherbiny ◽  
Ali A. Hammad ◽  
Ahmed A. Askar ◽  
Salwa A. Abou El Nour

Abstract Antibacterial coatings based on bacterial cellulose (BC) have been widely used in many fields including food packaging and wound dressing. In this study, we aimed to synthesis of colloidal AgNPs and BC/ AgNP composite by using BC as a reducing and capping agent in one step reaction induced by gamma-ray. Bacterial strain Komagataeibacter rhaeticus N1 MW322708 was used for biosynthesis BC by inoculation on Hestrin and Schramm medium and incubated statically at 35 °C for 10 days. BC sheet was formed, harvested, purified, and dried, then used for the synthesis of AgNPs and BC/AgNP by soaked 0.05 g of dried BC in 10ml of 1mM aqueous AgNO3 solution for 2h and then irradiated by gamma-ray under different doses. Color change from yellow to deep brown indicated the synthesis of AgNPs and BC/AgNP. The optical spectra of synthesized AgNPs revealed that the surface plasmon resonance was localized around 420 nm. DLS analysis showed that the mean diameter of AgNPs was 49.5 nm with a -19.36-mV value of zeta potential. TEM images revealed the spherical shape of synthesized AgNPs. The results of FESEM, FTIR, and XRD confirmed the formation of BC/AgNO3 composite. The highly crystalline nature of the BC membrane and BC/AgNP composite was observed in XRD measurements with a crystal size of 5.416 and 5.409 nm, respectively. The antibacterial activity of BC and BC/AgNP against pathogenic bacterial isolated from Pastirma food samples revealed that BC does not show antibacterial activity, while BC/AgNP composite showed antibacterial potency against Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, Proteus mirabilis, and Escherichia coli, with an inhibition zone of (mm) 9±1, 9±0.57, 10±1.15, 8±0.5 and 7±0.28, respectively. We concluded that this novel method presented in this paper offers a promising route for both AgNPs and BC/AgNP composites synthesis using a green, renewable biopolymer as a multifunctional agent and potential to be applied in the future development of food packing, biomedical instruments, and therapeutics.


Author(s):  
Raha Saremi ◽  
Nikolay Borodinov ◽  
Amine Mohamed Laradji ◽  
Suraj Sharma ◽  
Igor Luzinov ◽  
...  

Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.


Alginates extracted from brown seaweed have a variety of prospective applications such as thickeners, stabilizers, or restructuring agents. Due to its properties as a natural polysaccharide, alginate is very potential to be used as edible films for food packaging purposes. Edible films are developed for food protection being excellent barriers to gases but not to moisture. Incorporation of antimicrobial agents into edible film formulation can extend product shelf life and reduce the risk of pathogenic bacterial growth on food. Therefore, this study was aimed to develop an alginate based antibacterial edible film. Antibacterial agent extracted from lemongrass leaves using ethanol was employed. The study was conducted by varying the addition levels of lemongrass ethanol extract to the alginate based edible films, i.e. 0.5%, 1.0% and 1.5%. Before being added to the alginate based edible films, the lemongrass ethanol extract was investigated for its antibacterial activity. The edible films obtained were analyzed in terms of physical, mechanical and chemical and microbiological parameters, including thickness, water vapor transmission rate (WVTR), brightness, tensile strength, elongation, moisture content, water solubility and antibacterial activity. Results showed that the higher addition levels of lemongrass ethanol extract tended to produce alginate based edible films with lower WVTR and brightness value as well as higher elongation, moisture content and water solubility. Edible film added with lemongrass ethanol extract resulted in this study demonstrated antibacterial activity against Staphylococcus aureus. The addition of lemongrass alcohol extract at 0.5% was considered as a recommended concentration level for producing alginate based antibacterial edible films.


Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 280
Author(s):  
Rui Lu ◽  
Dur E. Sameen ◽  
Wen Qin ◽  
Dingtao Wu ◽  
Jianwu Dai ◽  
...  

Selenium is a natural element which exists in the human body and plays an important role in metabolism. Along with this, selenium also possesses antibacterial and antioxidant properties. Using selenium microparticles (SeMPs) in food packaging films is exceptional. In this experiment, a solution casting method was used to make film. For this purpose, we used polylactic acid (PLA) as a substrate for the formation of a film membrane while SeMPs were added with certain ratios to attain antibacterial and antioxidant properties. The effects of SeMPs on the PLA film and the value of SeMPs in food packaging film production were investigated. The effects of the SeMPs contents on the features of the film, such as its mechanical property, solubility, swelling capacity, water vapor permeability, antioxidant activity, and the antibacterial activity of the composite membrane against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) strains, were studied. The results manifest that the PLA/SeMPs films showed higher water resistance, UV resistance, antioxidant activity, and antibacterial activity than pure PLA film. When the concentration of SeMPs was 1.5 wt%, the composite membrane showed the best comprehensive performance. Although the tensile strength and elongation at break of the membrane were slightly reduced by the addition of SeMPs, the results show that PLA/SeMPs films are still suitable for food packaging and would be a very promising material for food packaging.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3238
Author(s):  
Raha Saremi ◽  
Nikolay Borodinov ◽  
Amine Mohamed Laradji ◽  
Suraj Sharma ◽  
Igor Luzinov ◽  
...  

Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings’ adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.


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