Antimicrobial Activity of Chitosan-Based Films Enriched with Green Tea Extracts on Murine Norovirus, Escherichia coli, and Listeria innocua

Edible films can be designed to serve as carriers of antimicrobial agents and be used to control pathogenic foodborne viruses and bacteria. This research tested this concept by dissolving green tea extract (GTE) in chitosan film-forming solutions (FFS) and using it to prepare dried chitosan edible films. As a control, the GTE was also dissolved in deionized water (DW). The FFS and the dried chitosan films with the GTE and the DW without chitosan were all evaluated against murine norovirus (MNV-1), Escherichia coli K12, and Listeria innocua. Both the FFS and the DW with GTE were incubated with ~107 PFU/ml of the virus suspensions for 3 h. The chitosan films with GTE were incubated for 4 and 24 h at 23±1°C. The results showed that the DW containing 1, 1.5, and 2.5% aqueous GTE, significantly (p<0.05) reduced MNV-1 plaques by 1.7, 2.5, and 3.3 logs after 3 h exposure, respectively. Similarly, FFS containing 2.5 and 5.0% GTE reduced MNV-1 counts by 2.5 and 4.0 logs, respectively, after 3 h exposure. The dried chitosan films with 5, 10, and 15% GTE were also effective against MNV-1 infectivity. After 24 h incubation, the 5 and 10% chitosan GTE films produced significant (p<0.05) titer reductions of 1.6 and 4.5 logs, respectively. Chitosan films containing 15% GTE reduced MNV-1 plaques to undetectable levels in 24 h. All chitosan GTE films reduced E. coli K12 and L. innocua populations to undetectable levels in tryptic soy broth after 24 h exposure. The results of this study showed that edible films enriched with GTE have potential to reduce both foodborne viruses and bacteria.

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Green tea extract: A natural antimicrobial with great potential for controlling native microbiota, Listeria innocua and Escherichia coli in fresh‐cut beet leaves

Journal of Food Safety ◽

10.1111/jfs.12374 ◽

2017 ◽

Vol 38 (1) ◽

Cited By ~ 5

Author(s):

María Verónica Fernández ◽

María Victoria Agüero ◽

Rosa Juana Jagus

Keyword(s):

Escherichia Coli ◽

Green Tea ◽

Green Tea Extract ◽

Listeria Innocua ◽

Natural Antimicrobial ◽

Fresh Cut ◽

Tea Extract

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Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.17:69-77 ◽

2017 ◽

Vol 17 (1) ◽

pp. 69-77

Author(s):

Tu Lijun ◽

Sun Hanju ◽

He Shudong ◽

Zhu Yongsheng ◽

Yu Ming ◽

...

Keyword(s):

Mass Spectrometry ◽

Escherichia Coli ◽

Green Tea ◽

Lactobacillus Acidophilus ◽

Pathogenic Bacteria ◽

Epigallocatechin Gallate ◽

Microbial Populations ◽

Medium Ph ◽

Bioactive Substance ◽

Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

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Antibacterial effect of green tea extract against multi drug resistant Escherichia coli isolated from urine sample of patients visiting tertiary care hospital of Eastern Nepal

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v8i1.27313 ◽

2020 ◽

Vol 8 (1) ◽

pp. 45-51

Author(s):

Kabita Giri ◽

Bijay Kumar Shrestha ◽

Jenish Shakya ◽

Shiv Nandan Sah ◽

Hemanta Khanal

Keyword(s):

Escherichia Coli ◽

Green Tea ◽

Antibacterial Effect ◽

Tertiary Care Hospital ◽

Tertiary Care ◽

Green Tea Extract ◽

Care Hospital ◽

Drug Resistant ◽

E Coli ◽

Tea Extract

Urinary tract infections (UTIs) caused by drug resistant (DR) Uropathogenic Escherichia coli have become a significant worldwide public health problem. Green tea (Camellia sinensis), has been reported to have antimicrobial activities against various pathogenic bacteria. The main aim of our study was to estimate the antibacterial effect of green tea extract against drug resistant Uropathogenic E. coli isolated from urine samples of patients visiting in tertiary care hospital from eastern Nepal. During the study 360 urine samples were collected from UTI suspected patients visiting a tertiary care hospital of Biratnagar. Urine samples were cultured by using semi-quantitative culture technique and bacteria was identified by standard microbiological procedure. Antibiotic susceptibility testing was done by Kirby-Bauer Disk Diffusion method according to NCCLS (2011) guidelines. The antibacterial effect of green tea extract was performed by preparing the 95% ethanol extract in Soxhlet apparatus which was dispensed in DMSO solution and sterilized by membrane filtration. Antibacterial activity of Green Tea Extract against MDR Uropathogenic Escherichia coli was performed by making different concentration of green tea. The overall prevalence of E. coli was 27.22% in study population whereas the prevalence of MDR E. coli was 21.08%. All the isolated E. coli exhibited 100% sensitivity towards Nitrofurantoin and it was still a drug of choice for the treatment of Urinary tract infection caused by E. coli. The green tea extracts exhibited effective antibacterial activity against MDR E. coli. The MIC of Green Tea Extract was found to be 600µg/ml for 24 MDR isolates and 1000µg/ml for remaining 11 isolates. Based on the present study it is concluded that Green Tea extracts have great potential as an antimicrobial agent against E. coli. Int. J. Appl. Sci. Biotechnol. Vol 8(1): 45-51

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Mechanism of the combined anti-bacterial effect of green tea extract and NaCl against Staphylococcus aureus and Escherichia coli O157:H7

Food Control ◽

10.1016/j.foodcont.2011.10.021 ◽

2012 ◽

Vol 25 (1) ◽

pp. 225-232 ◽

Cited By ~ 28

Author(s):

Motokazu Nakayama ◽

Naofumi Shigemune ◽

Takashi Tsugukuni ◽

Hitomi Jun ◽

Tomoyo Matsushita ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Green Tea ◽

Green Tea Extract ◽

Escherichia Coli O157 ◽

Tea Extract ◽

Bacterial Effect

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The Effect of Acidic and Alkaline pH on the Physico-Mechanical Properties of Surimi-Based Edible Films Incorporated with Green Tea Extract

Polymers ◽

10.3390/polym12102281 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2281

Author(s):

Sadia Munir ◽

Miral Javed ◽

Yang Hu ◽

Youming Liu ◽

Shanbai Xiong

Keyword(s):

Green Tea ◽

Protein Pattern ◽

Silver Carp ◽

Water Vapor Permeability ◽

Edible Films ◽

Green Tea Extract ◽

Vapor Permeability ◽

Acidic Ph ◽

Alkaline Ph ◽

Tea Extract

The effects of green tea extract (GTE) at acidic and alkaline pH (pH 3 and 11, respectively) on the physico-mechanical, thermal, and water transmission properties of silver carp surimi-based edible films were investigated. Incorporation of GTE significantly (p < 0.05) reduced elongation at break (EAB) but improved tensile strength (TS). Significant (p < 0.05) decreases in the solubility of films and water vapor permeability (WVP) were also perceived in GTE-containing films. Transparency and color were also affected, depending upon the concentration and pH. Films prepared at an acidic pH demonstrated significantly (p < 0.05) improved WVP, transparency, solubility, and thermal stability compared to those prepared at an alkaline pH. The protein pattern of films revealed a strong interaction between phenolic compounds of GTE and surimi proteins as evidenced by the presence of a myosin heavy chain (MCH) at the top of the gel. Generally, the addition of GTE at an acidic pH had significantly (p < 0.05) greater impact on film properties than at an alkaline pH and could offer great potential for surimi protein-based edible films with improved properties.

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Design of Chitosan and Alginate Emulsion-Based Formulations for the Production of Monolayer Crosslinked Edible Films and Coatings

Foods ◽

10.3390/foods10071654 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1654

Author(s):

Tiago M. Vieira ◽

Margarida Moldão-Martins ◽

Vítor D. Alves

Keyword(s):

Sodium Alginate ◽

Water Vapour ◽

Chitosan Film ◽

Tensile Tests ◽

Edible Films ◽

Vapour Permeability ◽

Hydrophobic Barrier ◽

Colour Parameters ◽

Chitosan Films ◽

Crosslinking Agents

This study aimed to develop edible monolayer emulsion-based barriers with polysaccharides as film-forming components (chitosan and sodium alginate), soy lecithin as a surfactant and olive oil as a hydrophobic barrier. Monolayer barriers in the form of films were prepared by casting filmogenic emulsions composed of 2% w/v chitosan (dissolved in lactic acid 1% v/v) or 1% w/v sodium alginate, with different lipid contents (25, 50 and 100% w/w biopolymer basis) and different surfactant concentrations (5, 10 and 25% w/w, lipid basis). Glycerol was used as a plasticizer (25 % w/w, biopolymer basis). After the emulsion drying process, the obtained stand-alone films were sprayed with a crosslinking solution, achieving an optimized crosslinker content of 3.2 mgCa2+/cm2 alginate film and 4 mg tripolyphosphate/cm2 chitosan film. The effect of oil and lecithin contents, as well the presence of crosslinking agents, on the film’s water vapour permeability (WVP), water vapour sorption capacity, mechanical properties and colour parameters, was evaluated. The results have shown that the lowest WVP values were obtained with formulations containing 25% lipid and 25% surfactant for chitosan films, and 100% lipid and 25% surfactant for alginate films. The application of the crosslinking agents decreased even further the WVP, especially for chitosan films (by 30%). Crosslinking also increased films’ resistance to deformation under tensile tests. Overall, the films developed present a good potential as polysaccharide-based barriers with increased resistance to water, which envisages the use of the designed formulations to produce either edible/biodegradable films or edible coatings.

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Edible Coating from Green Tea Extract and Chitosan to Preserve Strawberry (Fragaria vesca L.)

MATEC Web of Conferences ◽

10.1051/matecconf/201815601022 ◽

2018 ◽

Vol 156 ◽

pp. 01022

Author(s):

Dwi Apriyanti ◽

Nur Rokhati ◽

Novia Mawarni ◽

Zuroidatul Khoiriyah ◽

Titik Istirokhatun

Keyword(s):

Antimicrobial Activity ◽

Antioxidant Activity ◽

Green Tea ◽

Chitosan Film ◽

Antimicrobial Activities ◽

Edible Coating ◽

Green Tea Extract ◽

Phenolic Contents ◽

Chitosan Concentration ◽

Tea Extract

Food quality is an important factor in food sector. One way to increase the quality of food is by applying edible coating to slow down the degradation of foods quality. Combination of chitosan and green tea extract is one of the types of edible coating which many function as food preservative Green tea extract is chosen because of its high antioxidant contents. The goal of this research is to make a film from the composite of chitosan and green tea extract as a food coating and to observe the effect of chitosan concentration and the addition of green tea extract to the phenolic contents and antioxidant activity of the film. Moreover, this research also aims to apply chitosan film and green tea extract to foods, especially strawberries, and observing the effect of chitosan concentration and the addition of green tea extract to the shrinking of the fruit’s weight as well as its antimicrobial activities. Strawberries were coated with five different coating formula including one set as blank (uncoated fruit). The result of this research showed that the increasing of chitosan concentration and the volume of green tea extract addition also increase the antioxidant activity on the film. The phenolic contents on the green tea extract addition will also increase its phenolic contents as well. However, the increasing number of chitosan concentration can reduce the phenolic content on the film. Meanwhile, during the application to strawberries, it is found that 3% chitosan concentration which is combined with the addition of 2.5% green tea extract will minimize the shrinking of the fruit’s weight. Also 3% chitosan concentration will give a better antimicrobial activity. In the other side the addition of green tea extract will increase antioxidant activity, the addition of green tea extract also causing a decrease in antimicrobial activity.

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