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Kitsiou M, Purk L, Ioannou C, Wantock T, Sandison G, Harle T, Gutierrez-Merino J, Klymenko OV, Velliou E. On the evaluation of the antimicrobial effect of grape seed extract and cold atmospheric plasma on the dynamics of Listeria monocytogenes in novel multiphase 3D viscoelastic models. Int J Food Microbiol 2023; 406:110395. [PMID: 37734280 DOI: 10.1016/j.ijfoodmicro.2023.110395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/30/2023] [Accepted: 08/20/2023] [Indexed: 09/23/2023]
Abstract
The demand for products that are minimally processed and produced in a sustainable way, without the use of chemical preservatives or antibiotics have increased over the last years. Novel non-thermal technologies such as cold atmospheric plasma (CAP) and natural antimicrobials such as grape seed extract (GSE) are attractive alternatives to conventional food decontamination methods as they can meet the above demands. The aim of this study was to investigate the microbial inactivation potential of GSE, CAP (in this case, a remote air plasma with an ozone-dominated RONS output) and their combination against L. monocytogenes on five different 3D in vitro models of varying rheological, structural, and biochemical composition. More specifically, we studied the microbial dynamics, as affected by 1 % (w/v) GSE, CAP or their combination, in three monophasic Xanthan Gum (XG) based 3D models of relatively low viscosity (1.5 %, 2.5 % and 5 % w/v XG) and in a biphasic XG/Whey Protein (WPI) and a triphasic XG/WPI/fat model. A significant microbial inactivation (comparable to liquid broth) was achieved in presence of GSE on the surface of all monophasic models regardless of their viscosity. In contrast, the GSE antimicrobial effect was diminished in the multiphasic systems, resulting to only a slight disturbance of the microbial growth. In contrast, CAP showed better antimicrobial potential on the surface of the complex multiphasic models as compared to the monophasic models. When combined, in a hurdle approach, GSE/CAP showed promising microbial inactivation potential in all our 3D models, but less microbial inactivation in the structurally and biochemically complex multiphasic models, with respect to the monophasic models. The level of inactivation also depended on the duration of the exposure to GSE. Our results contribute towards understanding the antimicrobial efficacy of GSE, CAP and their combination as affected by robustly controlled changes of rheological and structural properties and of the biochemical composition of the environment in which bacteria grow. Therefore, our results contribute to the development of sustainable food safety strategies.
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Affiliation(s)
- Melina Kitsiou
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford GU2 7XH, UK; Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, London W1W 7TY, UK
| | - Lisa Purk
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford GU2 7XH, UK; Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, London W1W 7TY, UK
| | - Christina Ioannou
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Thomas Wantock
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere, GU27 3HA, UK
| | - Gavin Sandison
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere, GU27 3HA, UK
| | - Thomas Harle
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere, GU27 3HA, UK
| | | | - Oleksiy V Klymenko
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Eirini Velliou
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford GU2 7XH, UK; Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, London W1W 7TY, UK.
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Hinojosa-Dávalos J, Arias-Rios EV, Varela-Hernández JJ, Cardona-López MA, Orozco-Muñiz R, Cabrera-Diaz E. Thermal and Chemical Treatments To Reduce Salmonella on Alfalfa (Medicago sativa) and Broccoli (Brassica oleracea var. italica) Seeds before and during the Sprouting Process: A Hurdle Approach. J Food Prot 2020; 83:82-88. [PMID: 31851547 DOI: 10.4315/0362-028x.jfp-19-272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sprouts are vehicles of foodborne diseases caused by pathogens such as Salmonella. The aim of this study was to evaluate thermal and chemical treatments applied as a hurdle approach to reduce Salmonella in alfalfa (Medicago sativa) and broccoli (Brassica oleracea var. italica) seeds before and during their germination. Seeds, inoculated and then dried at 55°C for 48 h, were subjected to a chemical treatment and a thermal shock with (i) 75 mM caprylic acid at 70°C for 5 s, (ii) 0.04% CaO at 70°C for 5 s, or (iii) 1% H2O2 at 70°C for 5 s. After each treatment, seeds were immersed in water at 3°C for 5 s. Next, the imbibition process was carried out with 0.016% H2O2 at pH 3.0. Finally, the seeds were transferred to a rotary drum-type germinator and were sprayed with the same chemical solution that was applied before the imbibition process, for 20 s at intervals of 5 min for 40 min at 3 rpm. All chemical treatments reduced Salmonella at least 5 log CFU/g on both seeds. Germination rates between 90 and 93% were obtained after application of thermal and chemical treatments. Salmonella was not detected after the imbibition stage when caprylic acid and H2O2 treatments were applied. However, during the germination process of both seeds, Salmonella counts of >6 log CFU/g were obtained despite all treatments being applied at different stages of the sprouting process. These results demonstrated that thermal and chemical treatments used as a hurdle approach to control Salmonella on alfalfa and broccoli seeds significantly reduced the pathogen concentration on seeds >5 log but were ineffective to eliminate Salmonella and to control its growth during the sprouting process. The production of safe sprouts continues to be a major challenge for industry.
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Affiliation(s)
- Joel Hinojosa-Dávalos
- Departamento de Ciencias Básicas, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad No. 1115, Ocotlán, Jalisco, Mexico 47820 (ORCID: https://orcid.org/0000-0002-9967-2266 [J.H.-D.])
| | | | - Juan José Varela-Hernández
- Departamento de Ciencias Básicas, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad No. 1115, Ocotlán, Jalisco, Mexico 47820 (ORCID: https://orcid.org/0000-0002-9967-2266 [J.H.-D.])
| | - Marco Antonio Cardona-López
- Departamento de Ciencias Básicas, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad No. 1115, Ocotlán, Jalisco, Mexico 47820 (ORCID: https://orcid.org/0000-0002-9967-2266 [J.H.-D.])
| | - Ruben Orozco-Muñiz
- Departamento de Ciencias Básicas, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad No. 1115, Ocotlán, Jalisco, Mexico 47820 (ORCID: https://orcid.org/0000-0002-9967-2266 [J.H.-D.])
| | - Elisa Cabrera-Diaz
- Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Camino Ramón Padilla Sánchez 2100, Zapopan, Jalisco, Mexico 45200 (ORCID: https://orcid.org/0000-0002-1970-2104 [E.C.-D.])
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