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Aydin G, Zorlu EB. Characterisation and Antibacterial Properties of Novel Biodegradable Films Based on Alginate and Roselle ( Hibiscus sabdariffa L.) Extract. WASTE AND BIOMASS VALORIZATION 2022; 13:2991-3002. [PMID: 35222746 PMCID: PMC8856933 DOI: 10.1007/s12649-022-01710-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 02/01/2022] [Indexed: 06/01/2023]
Abstract
Composite films were prepared with alginate and roselle extract (HE) at different concentrations (1%, 3%, and 5% w/v) via solvent casting technique and analyzed in terms of physical, mechanical, and antibacterial properties. The incorporation of HE into alginate films resulted in rough and heterogeneous surface characteristics with increasing concentrations of HE. The thickness and water vapor permeability of alginate-HE composite films were significantly higher (p < 0.05) compared to pure alginate films. Moreover, water content, solubility, swelling, tensile strength, and elongation at break value of the composite films decreased (p < 0.05) with increasing concentrations of the extract. FTIR spectra revealed shifts and intensity variations in the composite films and the formation of new peaks suggesting a possible interaction between alginate and HE. Alginate-HE films exhibited good antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The antibacterial effect of the films, more pronounced against Gram-positive bacteria, increased with higher amounts of HE. The resulting films may be utilised as new biodegradable, antibacterial films in the food packaging industry to prolong shelf life and preserve food safety. Graphical Abstract Supplementary Information The online version of this article (10.1007/s12649-022-01710-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gulsum Aydin
- Biotechnology Department, Faculty of Sciences, Selcuk University, Konya, Turkey
| | - Elif Busra Zorlu
- Biotechnology Department, Faculty of Sciences, Selcuk University, Konya, Turkey
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Ailavadi S, Morgan MT, D'Souza DH. Aichi virus inactivation by heat in 2-ml glass vials. J Food Sci 2021; 86:4110-4118. [PMID: 33929042 DOI: 10.1111/1750-3841.15747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/28/2022]
Abstract
Aichi virus (AiV) that results in gastroenteritis worldwide, is spread through contaminated shellfish and water. The resistance/tolerance of AiV to common inactivation processes along with the absence of commercially available vaccines makes it necessary to study its thermal inactivation kinetics. This research evaluated the heat inactivation of AiV in cell-culture media using 2-ml sterile glass vials by the linear and Weibull models. Heat treatments of AiV titers of 7 log plaque forming units (PFU)/ml were conducted thrice in a water-bath at 50, 54, and 58 °C for up to 90 min. Plaque assays for each dilution in duplicate were used to determine infectious virus titers. Linear model D-values for AiV at 50 ± 1 °C (± = standard error) (come-up time = 68 s), 54 ± 0.7 °C (130 s), and 58 ± 0.6°C (251 s) were 43.3 ± 4.23 (R2 = 0.40, RMSE = 0.56), 5.69 ± 0.28 (R2 = 0.80, RMSE = 0.43), and 1.20 ± 0.63 min (R2 = 0.69, RMSE = 0.39), respectively, and the linear model z-value was 5.14 ± 0.39°C (R2 = 0.99, RMSE = 0.08). For the same temperatures, the Weibull model td = 1 values were 20.98 ± 8.8 (R2 = 0.62, RMSE = 0.46, α (scale parameter) = 2.30, β (shape parameter) = 0.38), 3.84 ± 0.69 (R2 = 0.85, RMSE = 0.38, α = 1.08, β = 0.66), and 0.87 ± 0.10 min (R2 = 0.80, RMSE = 0.32, α = 0.22, β = 0.61), respectively and the z-value (using Td = 1 ) was 5.79 ± 0.22 °C (R2 = 1.0, RMSE = 0.03). A better fit was obtained with the Weibull model for log reductions versus time with higher R2 and lower RMSE values. Application of AiV inactivation parameters can help reduce the risk of AiV outbreaks.
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Affiliation(s)
- Sukriti Ailavadi
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
| | - Mark T Morgan
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
| | - Doris H D'Souza
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
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Joshi SS, D'Souza DH. Grape seed extract against Aichi virus infectivity in model foods and contact surfaces. Food Microbiol 2021; 98:103784. [PMID: 33875212 DOI: 10.1016/j.fm.2021.103784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 10/22/2022]
Abstract
Aichi virus (AiV) is an enteric virus that affects humans and is prevalent in sewage waters. Effective strategies to control its spread need to be explored. This study evaluated grape seed extract (GSE) for: a) antiviral potential towards AiV infectivity at 37 °C and room temperature (RT); b) antiviral behavior in model foods (apple juice (AJ) and 2% fat milk) and also simulated gastric environments; and c) potential application as a wash solution on stainless steel surfaces. GSE at 0.5 mg/mL decreased AiV suspensions containing ~4.75 log PFU/mL to titer levels that were not detected after 30 s at both 37 °C and RT. Infectious AiV titers were not detected after 5 min treatment with 1 mg/mL GSE at 37 °C in AJ. GSE at 2 mg/mL and 4 mg/mL in 2% fat milk decreased AiV after 24 h by 1.18 and 1.57 log PFU/mL (4.75 log PFU/mL to 2.86 and 3.25 log PFU/mL), respectively. As a surface wash, GSE at 1 mg/mL after 30 s decreased AiV to undetectable levels under clean conditions. With organic load (mimicking unclean conditions), 2 and 4 mg/mL GSE reduced AiV after 5 min by 1.13 and 1.71 log PFU/mL, respectively. Overall, GSE seems to be a promising antiviral agent against AiV at low concentrations and short contact times.
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Affiliation(s)
- Snehal S Joshi
- The University of Tennessee, Institute of Agriculture, Department of Food Science, 2600 River Drive, Knoxville, TN, 37996, USA
| | - Doris H D'Souza
- The University of Tennessee, Institute of Agriculture, Department of Food Science, 2600 River Drive, Knoxville, TN, 37996, USA.
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Takeda Y, Okuyama Y, Nakano H, Yaoita Y, Machida K, Ogawa H, Imai K. Antiviral Activities of Hibiscus sabdariffa L. Tea Extract Against Human Influenza A Virus Rely Largely on Acidic pH but Partially on a Low-pH-Independent Mechanism. FOOD AND ENVIRONMENTAL VIROLOGY 2020; 12:9-19. [PMID: 31620998 PMCID: PMC7223586 DOI: 10.1007/s12560-019-09408-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/01/2019] [Indexed: 05/28/2023]
Abstract
Influenza A virus (IAV) infection is perennially one of the leading causes of death worldwide. Effective therapy and vaccination are needed to control viral expansion. However, current anti-IAV drugs risk inducing drug-resistant virus emergence. Although intranasal administration of whole inactivated virus vaccine can induce efficient protective immunity, formalin and β-propiolactone are the currently used and harmful inactivating agents. Here, we analyzed the antiviral activity of hibiscus (Hibiscus sabdariffa L.) tea extract against human IAV and evaluated its potential as a novel anti-IAV drug and a safe inactivating agent for whole inactivated vaccine. The in vitro study revealed that the pH of hibiscus tea extract is acidic, and its rapid and potent antiviral activity relied largely on the acidic pH. Furthermore, the mouse study showed that the acidic extract was not effective for either therapeutic or vaccination purposes. However, hibiscus tea extract and protocatechuic acid, one of the major components of the extract, showed not only potent acid-dependent antiviral activity but also weak low-pH-independent activity. The low-pH-independent activity did not affect the conformation of immunodominant hemagglutinin protein. Although this low-pH-independent activity is very limited, it may be suitable for the application to medication and vaccination because this activity is not affected by the neutral blood environment and does not lose antigenicity of hemagglutinin. Further study of the low-pH-independent antiviral mechanism and attempts to enhance the antiviral activity may establish a novel anti-IAV therapy and vaccination strategy.
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Affiliation(s)
- Yohei Takeda
- Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido, 080-8555, Japan
| | - Yuko Okuyama
- Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan
| | - Hiroto Nakano
- Division of Sustainable and Environmental Engineering, Graduate School of Engineering, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, 050-8585, Japan
| | - Yasunori Yaoita
- Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan
| | - Koich Machida
- Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan
| | - Haruko Ogawa
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido, 080-8555, Japan.
| | - Kunitoshi Imai
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido, 080-8555, Japan
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Joshi SS, Howell AB, D'Souza DH. Antiviral effects of blueberry proanthocyanidins against Aichi virus. Food Microbiol 2019; 82:202-208. [PMID: 31027775 DOI: 10.1016/j.fm.2019.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 01/12/2023]
Abstract
Blueberry polyphenols are known for their high antioxidant and antimicrobial potential. Aichi virus (AiV) is an emerging human enteric virus that causes gastroenteritis outbreaks worldwide. This study aimed to (1) determine the time- and dose-dependent effects of blueberry proanthocyanidins (B-PAC) against AiV over 24 h at 37 °C; (2) gain insights on their mode of action using pre- and post-treatment of host cells and Transmission Electron Microscopy; and (3) determine their anti-AiV effects in model foods and under simulated gastric conditions. AiV at ∼5 log PFU/ml was incubated with equal volumes of commercial blueberry juice (BJ, pH 2.8), neutralized BJ (pH 7.0), B-PAC (2, 4, and 10 mg/ml) prepared either in 10% ethanol, apple juice (AJ), 2% milk, simulated gastric fluid (SGF, pH 1.5) or simulated intestinal fluid (SIF, pH 7.5), and controls (malic acid (pH 3.0), phosphate buffered saline (pH 7.2), apple juice (pH 3.6) and 2% milk) over 24 h at 37 °C, followed by standard plaque assays. Each experiment was replicated thrice and data were statistically analyzed. Differences in AiV titers with 1 mg/ml B-PAC were 2.13 ± 0.06 log PFU/ml lower after 24 h and ≥3 log PFU/ml (undetectable levels) lower with 2 and 5 mg/ml B-PAC compared to AiV titers in PBS after 24 h and 3 h, respectively. BJ at 37 °C resulted in titer differences (lower titers compared to PBS) of 0.17 ± 0.06, 1.27 ± 0.01, and 1.73 ± 0.23 log PFU/ml after 1, 3, and 6 h and ≥3 log PFU/ml after 24 h. Pre- and post-treatment of host cells with 0.5 mg/ml B-PAC caused titer decreases of 0.62 ± 0.33 and 0.30 ± 0.06 log PFU/ml, respectively suggesting a moderate effect on viral-host cell binding. B-PAC at 2 mg/ml in AJ caused titer differences of ≥3 log PFU/ml after 0.5 h, while differences of 0.84 ± 0.03 log PFU/ml with 5 mg/ml B-PAC in milk, and ≥3 log PFU/ml with B-PAC at 5 mg/ml in SIF after 30 min were obtained. This study shows the ability of BJ and B-PAC to decrease AiV titers to potentially prevent AiV-related illness and outbreaks.
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Affiliation(s)
- Snehal S Joshi
- Department of Food Science, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA
| | - Amy B Howell
- Rutgers University, Marucci Center for Blueberry Cranberry Research, Chatsworth, NJ, 08019, USA
| | - Doris H D'Souza
- Department of Food Science, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA.
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Monomeric catechin and dimeric procyanidin B2 against human norovirus surrogates and their physicochemical interactions. Food Microbiol 2018; 76:346-353. [PMID: 30166160 PMCID: PMC7126691 DOI: 10.1016/j.fm.2018.06.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/15/2018] [Accepted: 06/15/2018] [Indexed: 11/23/2022]
Abstract
Plant polyphenols have shown antiviral activity against several human pathogens, but their physicochemical interactions are not well-understood. The objectives of this study were to compare the antiviral activity between monomeric catechin and dimeric procyanidin B2 (PB2) using cultivable human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) and to understand their potential antiviral mechanism using virus-like particles (VLPs) and the P domain of human norovirus GII (HNoV GII.4). Surrogate viruses at 5 log PFU/mL were treated with 0.5–5 mg/mL monomeric catechin monohydrate, PB2 or phosphate buffered saline (PBS, pH 7.2; control) at 37 °C over 24 h. Infectivity was determined using plaque assays and data from triplicate experiments were statistically analyzed. PB2 at 0.5 mg/mL and 1 mg/mL reduced FCV-F9 to undetectable levels after 3 h and MNV-1 by 0.21 and 1.23 log PFU after 24 h, respectively. Monomeric catechins at 1 mg/mL reduced FCV-F9 to undetectable levels after 6 h and MNV-1 titers to undetectable levels after 24 h. In addition, PB2 was shown to directly bind the P domain, the main capsid structure of HNoVs in the ratio of 1:1 through spontaneous interactions. Electrostatic interactions played a dominant role between PB2 and the P domain. PB2 significantly altered tertiary but not secondary structures of VLPs. Transmission electron microscopy demonstrated that PB2 aggregated VLPs, further indicating interactions between them. These findings indicate that PB2 causes structural changes of the P domain of VLPs, mainly through direct interaction leading to HNoV inactivation. Polymeric procyanidins cause higher reduction of human norovirus surrogate titers than monomers. Binding of procyanidin to human norovirus-like particles alters capsid structure. Procyanidin binding to viral capsid results in decreased infectivity.
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Deng W, Gibson KE. Interaction of microorganisms within leafy green phyllospheres: Where do human noroviruses fit in? Int J Food Microbiol 2017; 258:28-37. [DOI: 10.1016/j.ijfoodmicro.2017.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/21/2017] [Accepted: 07/18/2017] [Indexed: 02/06/2023]
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