Design and fabrication of smart and biodegradable food packaging film using anthocyanins from eggplant peel based on starch-chitosan polymer modified with green-synthesized copper nanoparticles

The green synthesis of copper nanoparticles refers to the preparation of nanoparticles using eco-friendly and sustainable processes, often involving plant extracts, microorganisms, or other natural sources. As a sustainable approach with many potential applications, plant extracts could be used for the green synthesis of copper nanoparticles. The green synthesis of copper nanoparticles from plants, such as Erioglossum rubiginosum, involves using leaf and seed extracts to reduce copper ions to form nanoparticles. Primarily, copper nanoparticles are confirmed by visual observation of the aluminum vessel’s inner wall exhibiting a glossy, reddish-brown precipitate. Further, the UV–Vis spectrophotometer is employed to detect the presence of CuNPs. The peak is at 631 nm, which is unique to CuNPs. FTIR data show the presence of a capping agent which stabilizes copper nanoparticles. The peaks at 3,265 cm−1 for the hydroxy group (H-bonded OH stretch) indicate alcohols and phenols; 1610 cm−1 for aromatic ring stretch; and 1,075 cm−1 for aliphatic fluoro compounds (C–F stretch). DPPH reducing power assay is used to verify the antioxidant activity. Both plant extracts and the synthesized CuNPs showed considerable antioxidant activity. The seed and leaf extract of Erioglossum rubiginosum used for the green synthesis of copper nanoparticles served as a capping agent due to the presence of antioxidant phytoconstituents. Then, we used Paramphistomum cervi to evaluate the anthelmintic activity of aqueous extracts of leaves and seeds of Erioglossum rubiginosum. After that, we assessed the anthelmintic activity of the green synthesized copper nanoparticles (CuNPs). We observed that the extracts showed a significant and dose-dependent decrease in the paralysis time and death time of parasites whereas better activity was found from the synthesized CuNPs. At last, we claim that comprehensive investigation on plant extracts and CuNPs could be carried out for further study and might pave the way for development of novel therapeutic agents that show efficacy against diverse parasitic infections.

Physical properties and antilisterial activity of bioactive edible films containing Lactobacillus plantarum

Over the past years, the field of nanotechnology has immensely evolved. It is no longer a single industry but now has developed to become a shared collection of materials and practices as it has created a larger impact on various industries such as chemicals, electronics, agriculture, medicine and space. The usage of nanoparticles in the medical industry has gained a lot of interest lately due to their promising properties making them an excellent focus of interest. Green synthesis of copper nanoparticles has shown to be advantageous as it is highly conductive and inexpensive than silver and gold. However, the downfall is the aggregation and oxidation of copper nanoparticles. The usage and selection of a suitable stabilizer for the capping of copper nanoparticles can overcome these problems. The present study reveals copper nanoparticles synthesized from leaf extract of Psidium guajava L., displayed antifungal efficacy against the pathogen Candida albicans with a 0.5 cm zone of inhibition. The synthesized copper nanoparticle shows anticancer activity in HeLa cell lines with 1000 g/ml concentration of the nanoparticle. In future, the copper nanoparticles can be effective in the treatment of cancer and human pathogens.

Aims: Nanotechnology is the science which is about manipulating matter, atom by atom and is associated with particles smaller than 100 nm in size. Copper nanoparticles are used mainly due to its surplus amount, low cost, easy availability and biocompatible property. Green synthesis of copper nanoparticles is very simple, economical and eco-friendly method that does not involve any toxic chemicals. The aim of our study is green synthesis of copper nanoparticles using green tea and neem formulation and assessment of its antimicrobial effects.Place and Duration of Study: Sample: Department of Nanotechnology, Saveetha dental college and hospitals, between December 2020 and January 2021Methodology: 20 mM of copper sulphate solution is mixed with 40mL of plant extract and 60 mL of distilled water was added and made it into 100 ml solution. Once the copper nanoparticles are synthesized the solution is characterized using UV- vis-spectroscopy and was scanned in double beam UV-vis- spectrophotometer from 300 nm to 700nm wavelength. The antimicrobial property of copper nanoparticle is evaluated by agar well diffusion method.Results: The colour change from green to brown and peak observed in UV-vis- spectrophotometer was associated with the synthesis of copper nanoparticles. Copper nanoparticle from green tea and tea extract has good antimicrobial activity against S.mutans, C.albicans, E.faecalis, S, aureus.Conclusion: Copper nanoparticles can be efficiently synthesised from green and neem formulation.hese copper nanoparticles showed good antibacterial properties and are effective against oral pathogens

The utilization of exces whey is necessary to reduce dairy waste because the large amount of whey disposal in waste streams has caused environmental problems. During whey protein film production as the effective means of utilization of excess whey, we have examined the effects of pH, temperature, and plasticizers for water vapor permeability (WVP), tensile strength (TS), and elongation rate (%E) of the whey protein films. The 10% whey protein films had the highest WVP (28.73 g·mm/kPa·day·m2) and TS (1.85±0.11 Mpa). But, in this case, an increase of WVP was caused by the thickness of whey protein films. At the concentration of 8% whey protein, appropriate thickness was obtained. Whey protein films prepared at the pH 6.75 and 95°C showed lower WVP (28.38 g·mm/kPa·day·m2) and elongation rate (12.9%) and higher TS value (3.769±0.407 MPa) than at the pH 6.75 and 75°C. As the temperature increased, WVP of films decreased slightly and tensile strength increased slightly, while elongation rate decreased significantly. Higher WVP and TS were observed at pH 6.75 compared to pH 7–9. In contrast, significantly higher elongation was observed at pH 9 compared to pH 6.75–8. Among the plasticizer type used, the addition of sorbitol showed the highest TS value (6.244±0.297 MPa) at the concentration of 0.4 g sorbitol and elongation rate (49%) at the concentration of 0.6 g sorbitol.

Facile microwave-mediated green synthesis of non-toxic copper nanoparticles using Citrus sinensis aqueous fruit extract and their antibacterial potentials

Prevention of bacterial growth among root canal treatment sessions is a prerequisite for successful root canal treatment. The most common way to achieve this is to use calcium hydroxide in the treatment sessions. Some studies have shown calcium hydroxide inefficiency in this field. The aim of this study was to investigate and compare the effects of silver, copper, zinc oxide and magnesium oxide nanoparticles on the inhibitory effects of calcium hydroxide based on Enterococcus faecalis species. Enterococcus faecalis bacteria having 0.5 McFarland concentration were prepared. Plates containing BHI agar medium were prepared. In each plate, four wells were created and the plate was cultured using a sterile swab. Afterwards, calcium hydroxide composition of 1% and 2% concentration from silver, copper, zinc oxide and magnesium oxide nanoparticles were prepared separately, as well as the combination of calcium hydroxide with 1% silver in combination with 1% of copper, zinc oxide and magnesium oxide nanoparticles, which were then transferred to the wells. After 24 hours of incubation, the inhibition zone diameter was measured. Data were analyzed by Mann-Withney test. At 1% concentration, only the combination of copper nanoparticles with calcium hydroxide could significantly create an inhibition zone larger than calcium hydroxide alone (P value <0.5). At 2% concentration, the combination of copper nanoparticles with calcium hydroxide, and the combination of silver nanoparticles with calcium hydroxide, were significantly higher than calcium hydroxide alone (P value <0.5). The calcium hydroxide composition containing 1% silver nanoparticles in combination with 1% copper, zinc oxide and magnesium oxide nanoparticles significantly increased the growth inhibition zone more than calcium hydroxide alone. (P Value <0.5). Copper nanoparticles showed the best antibacterial properties among silver, copper, magnesium oxide and zinc oxide nanoparticles in combination with calcium hydroxide. Also, the combination of 1% of nanoparticles with each other increases antibacterial properties.

The synthesis of metal nanoparticles using plant extracts is a very promising method in green synthesis. The medicinal value of Moringa oleifera leaves and the antimicrobial activity of metallic copper were combined in the present study to synthesize copper nanoparticles having a desirable added-value inorganic material. The use of a hydroalcoholic extract of M. oleifera leaves for the green synthesis of copper nanoparticles is an attractive method as it leads to the production of harmless chemicals and reduces waste. The total phenolic content in the M. oleifera leaves extract was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. The M. oleifera leaves extract was treated with a copper sulphate solution. A color change from brown to black indicates the formation of copper nanoparticles. Characterization of the synthesized copper nanoparticles was performed using ultraviolet-visible light (UV-Vis) spectrophotometry, Fourier-transform infrared (FTIR) spectrometry, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The synthesized copper nanoparticles have an amorphous nature and particle size of 35.8-49.2 nm. We demonstrate that the M. oleifera leaves extract and the synthesized copper nanoparticles display considerable antioxidant activity. Moreover, the M. oleifera leaves extract and the synthesized copper nanoparticles exert considerable anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 µg/mL; MIC values for the copper nanoparticles: 500, 500, 500, and 250 µg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized copper nanoparticles exert relatively stronger anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 µg/mL; MIC values for the copper nanoparticles: 125, 125, 62.5, and 31.2 µg/mL, respectively). Our study reveals that the green synthesis of copper nanoparticles using a hydroalcoholic extract of M. oleifera leaves was successful. In addition, the synthesized copper nanoparticles can be potentially employed in the treatment of various microbial infections due to their reported antioxidant, anti-bacterial, and anti-fungal activities.

Bioactive nanocomposite diffusion films containing plant essential oils (EOs) and silver nanoparticles (AgNPs) were fabricated and tested against foodborne pathogens, spoilage organisms, and insects in packaged foods. Films were based on chitosan (CH), poly(butylene adipate-co-terephthalate) (PBAT), and polylactic acid (PLA), containing cellulose nanocrystals (CNCs), plasticizers such as glycerol (Gly) or polyethylene glycol (PEG), and three active mixtures of EOs/AgNPs (AC-1, AC-2, or AC-3). Films were characterized by their mechanical properties, water solubility (WS), water vapor permeability (WVP), in vitro antibacterial/antifungal and insecticidal properties, and release kinetics in food simulants. PBAT and PLA films displayed higher barrier properties, and no solubility compared to CH films. Bioactive CH and PBAT films showed stronger antibacterial/antifungal, and insecticidal properties against Escherichia coli O157:H7, Salmonella Typhimurium, Aspergillus niger, Penicillium chrysogenum, Mucor circinelloides, and rice weevil Sitophilus oryzae, compared to bioactive PLA film. Challenge tests were conducted on rice and yogurt inoculated with selected bacteria and fungi by applying the diffusion films. Rice was treated with bioactive CH and PBAT films, in combination with gamma (γ)-irradiation (0.75 kGy) and stored for 8 weeks. Yogurt was treated with PBAT and PLA films for 8 weeks. Results showed that bioactive films significantly reduced the growth of bacteria/fungi in both food samples. The growth of insects inoculated in rice treated with bioactive films in combination with irradiation (0.1-0.3 kGy) was controlled from the first week of storage. A combined treatment of irradiation at 3 kGy with bioactive films increased significantly the insect mortality up to 96%-100%, from Day 7 to 14 compared to treatment with bioactive films alone. PRACTICAL APPLICATIONS: Nanocomposite bioactive diffusion films developed in this study could be applied as diffusion devices of active natural compounds not only for the control of bacteria/fungi and pest insects in packaged rice (with a possible combined treatment with γ-irradiation), but also for that of bacteria/fungi in yogurt. The active formulations could be used in the food industry for controlling insect proliferation in the sector of stored cereals but also to prevent bacterial and fungal contamination in cereals and dairy products such as yogurts and their derived products.

&nbsp;Copper and chromium-based nanoparticles are employed in the treatment of various diseases due to their antifungal, antiviral, antibacterial, and antioxidant properties.&nbsp; Recent research conducted at the University of Okara aimed to evaluate the antibacterial, antifungal, and antioxidant potential of copper and chromium-doped manganese oxide nanoparticles.&nbsp; The nanoparticles were synthesized using the hydrothermal method. To determine their antibacterial potential, disc diffusion and agar well diffusion methods were utilized. Characterization of the nanoparticles was performed using powder X-ray diffraction, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy to confirm their properties. The antibacterial efficacy of the nanoparticles was tested against Klebsiella pneumoniae, E. coli, and Bacillus subtilis&nbsp; All antibiotics demonstrated antibacterial activity except Trimethoprim and Amoxicillin, while copper-doped manganese&nbsp; oxide nanoparticles showed no antibacterial potential. Chromium-doped manganese oxide nanoparticles exhibited antibacterial potential at various concentrations. The antifungal potential of copper nanoparticles was tested against Fusarium equiseti and Rhizopus stolonife. No inhibition was observed against the growth of Rhizopus stolonifer. The antioxidant activity test confirmed that copper and chromium oxide nanoparticles, along with ascorbic acid, possess antioxidant properties. Copper oxide nanoparticles exhibited a maximum antioxidant activity of 67% at a concentration of 0.1 mg/2 ml, while ascorbic acid showed 90%. Chromium oxide nanoparticles demonstrated maximal antioxidant activity of 99%, with ascorbic acid at 83%. Copper nanoparticles had less antioxidant activity than ascorbic acid, whereas chromium nanoparticles had higher activity. &nbsp; In conclusion, both copper and chromium-doped manganese oxide nanoparticles exhibit antibacterial, antifungal, and antioxidant activities against different pathogens.&nbsp;

Antibacterial poly(butylene succinate-co-terephthalate)/titanium dioxide/copper oxide nanocomposites films for food packaging applications

Nanotechnology is the science which is about manipulating matter, atom by atom and is associated with particles smaller than 100 nm in size. Copper nanoparticles are used mainly due to its surplus amount, low cost, easy availability and biocompatible property. Green synthesis of copper nanoparticles is very simple, economical and eco-friendly method that does not involve any toxic chemicals. The aim of our study is green synthesis of copper nanoparticles using green tea and neem formulation and assessment of its antimicrobial effects. 20mM of copper sulphate solution is mixed with 40mL of plant extract and 60 mL of distilled water was added and made it into 100 ml solution. Once the copper nanoparticles are synthesized the solution is characterized using UV- vis-spectroscopy and was scanned in double beam UV-vis- spectrophotometer from 300 nm to 700nm wavelength. The antimicrobial property of copper nanoparticle is evaluated by agar well diffusion method. The colour change from green to brown and peak observed in UV-vis- spectrophotometer was associated with the synthesis of copper nanoparticles. Copper nanoparticle from green tea and tea extract has good antimicrobial activity against S.mutans, C.albicans, E.faecalis, & S.aureus. Copper nanoparticles can be efficiently synthesised from green and neem formulation. These copper nanoparticles showed good antibacterial properties and are effective against oral pathogens.

در تحقیق حاضر بمنظور بهبود خواص فیزیکی و مکانیکی فیلم‌های زیست تخریب‌پذیر خوراکی ترکیب کردن دو پلیمر کربوکسی‌متیل‌سلولز (CMC) و کتیرا مورد مطالعه قرار گرفت. کربوکسی‌متیل‌سلولز و کتیرا با نسبت‌های 25:75، 50:50 و 75:25 با یکدیگر ترکیب شده و میزان نفوذپذیری به بخار آب، درصد حلالیت، خواص مکانیکی و ریزساختار آنها ارزیابی گردید. نتایج نشان داد که در میان سه نسبت مرکب دو پلیمر، میزان استحکام کششی در نسبت 50:50 نسبت به دو ترکیب دیگر بیشتر بود طوری که مقدار آن در نسبت های 50:50، 25:75 و 75:25، به ترتیب 59/44، 82/32 و 59/26 مگاپاسکال بوده است. نفوذپذیری به بخار آب در ترکیب 50:50 و 75:25 نسبت به ترکیب 25:75 از شرایط بهتری برخوردار بود. ویژگی حلالیت در آب در سه فیلم ترکیبی تفاوتی با یکدیگر نداشتند ولیکن دارای کیفیت بهتری نسبت به فیلم خالص CMC بودند طوری که مقدار 52 الی 58 درصد نسبت به فیلم خالص CMC کاهش معنی‌داری را در میزان حلالیت به نمایش گذاشتند. همچنین، ترکیب کردن دو پلیمر در نسبت‌های مختلف توانست از میزان حساسیت فیلم‌ها نسبت به رطوبت بکاهد. بطورکلی، از نتایج این تحقیق دریافت می شود که ترکیب کردن دو پلیمر می تواند برخی ویژگی‌های فیزیکی- مکانیکی فیلم خوراکی تهیه شده از کربوکسی‌متیل‌سلولز- کتیرا را بهبود بخشد.

Application of anthocyanin as a color indicator in gelatin films

This research was aimed to develop an active film from chitosan film incorporated with green tea extract to enhance antioxidant and antimicrobial properties in order to be used for food shelf life extension. The experiments were divided into 3 parts. Firstly, chitosan-based film preparation and modification were determined. The results suggested that the optimum chitosan films could be prepared from 2% chitosan in 1% acetic acid. However, the chitosan film was brittle and had low flexibility. Mechanical property of chitosan film was modified by adding different concentrations of glycerol, as a plasticizer, including 0, 10, 20, 30, 40 and 50% (w/w of chitosan). The effect of plasticizer concentration on the mechanical properties of the chitosan film was determined by measuring their tensile strength, elongation at break, thickness, surface colors and water vapor transmission rate. The results showed that 30% glycerol was the optimum concentration to improve flexibility, while maintaining tensile strength and other physical properties of the film. Secondly, chitosan-based film was incorporated with green tea extract (GT) in order to improve film’s antioxidant and antimicrobial properties. The optimum concentration of green tea extract was then determined by adding 0, 2, 5, 10 and 20% (w/v) of green tea in film-forming solution, and tensile strength, elongation at break, water vapor permeability (WVP), density, total phenolic compounds (TPC), radicals scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) of the film were determined. Fourier Transform Infrared (FTIR) spectrometry was carried out to observe the potential modifications of the chitosan films when incorporated with GTE. The ability to inhibit Staphylococcus aureus TISTR 118, Salmonella enteritidis DMST 17368, Escherichia coli TISTR 780 and Pseudomonas fluorescens TISTR 358 was conducted using agar diffusion method. It was found that WVP and lightness (L) decreased, while density, TPC, DPPH scavenging activity, redness (a), and yellowness (b) increased with increasing green tea concentration. The results also showed that films containing green tea extract had inhibition zone and could inhibit bacterial growth underneath film, while chitosan-alone film had no inhibition zone. The results suggested that incorporation of GT into chitosan films improved mechanical and water vapor barrier properties and enhanced polyphenolic content, antioxidant activity and antimicrobial property of the films. Changes in the FTIR spectra of the chitosan films were observed when GTE was incorporated, suggesting some interactions occurred between amine group of chitosan and hydroxyl group of green tea polyphenols. Lastly, the chitosan film containing green tea extract (CGT-film) was used as an active film for shelf life extension of pork sausage. Qualities of pork sausages wrapped with CGT-film were compared with those wrapped with chitosan-alone film without green tea incorporation (C-film) and those without chitosan film wrapping (Control). Changes in the physical qualities including color values and texture, the chemical qualities including pH and thiobarbituric value (TBA), the microbiological qualities including total plate count, yeasts/moulds, and lactic acid bacteria were determined throughout the storage. The sensory qualities including odor, color, slime formation, and overall acceptance were also evaluated using Quantitative Descriptive Analysis. The results showed that samples wrapped with CGT-film had higher cutting force, lightness and yellowness values, but lower TBA and microbial growth than those wrapped with C-film and control. Based on microbiological analysis and sensory evaluation, control samples and those wrapped with C-film had shelf life of less than 12 and 20 days, respectively. Samples wrapped with GCT-film had better qualities than other samples and had shelf life of up to 20 days at 4℃. Incorporation of GT into chitosan film could enhance the antioxidant and antiomicrobial properties of the film. CGT-film reduced the lipid oxidation and inhibited microbial growth and, consequently, could maintain qualities and extended shelf life of the pork sausage.