title: Synergistic combinations of high hydrostatic pressure and essential oils or their constituents and their use in preservation of fruit juices.
abstract: This work addresses the inactivation achieved with Escherichia coli O157:H7 and Listeria monocytogenes EGD-e by combined processes of high hydrostatic pressure (HHP) and essential oils (EOs) or their chemical constituents (CCs). HHP treatments (175-400 MPa for 20 min) were combined with 200 μL/L of each EO (Citrus sinensis L., Citrus lemon L., Citrus reticulata L., Thymus algeriensis L., Eucalyptus globulus L., Rosmarinus officinalis L., Mentha pulegium L., Juniperus phoenicea L., and Cyperus longus L.) or each CC ((+)-limonene, α-pinene, β-pinene, p-cymene, thymol, carvacrol, borneol, linalool, terpinen-4-ol, 1,8-cineole, α-terpinyl acetate, camphor, and (+)-pulegone) in buffer of pH 4.0 or 7.0. The tested combinations achieved different degrees of inactivation, the most effective being (+)-limonene, carvacrol, C. reticulata L. EO, T. algeriensis L. EO and C. sinensis L. EO which were capable of inactivating about 4-5 log(10) cycles of the initial cell populations in combination with HHP, and therefore showed outstanding synergistic effects. (+)-Limonene was also capable of inactivating 5 log(10) cycles of the initial E. coli O157:H7 population in combination with HHP (300 MPa for 20 min) in orange and apple juices, and a direct relationship was established between the inactivation degree caused by the combined process with (+)-limonene and the occurrence of sublethal injury after the HHP treatment. This work shows the potential of EOs and CCs in the inactivation of foodborne pathogens in combined treatments with HHP, and proposes their possible use in liquid food such as fruit juices.
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Espina
authors.forename: Diego
authors.initials: D
authors.lastname: García-Gonzalo
authors.forename: Amin
authors.initials: A
authors.lastname: Laglaoui
authors.forename: Bernard M
authors.initials: BM
authors.lastname: Mackey
authors.forename: Rafael
authors.initials: R
authors.lastname: Pagán
mesh_terms: D001628:Beverages; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000187:drug effects / Q000502:physiology; D005519:Food Preservation / Q000379:methods*; D005638:Fruit; D006874:Hydrostatic Pressure; D008089:Listeria monocytogenes / Q000187:drug effects / Q000502:physiology; D050296:Microbial Viability / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D009822:Oils, Volatile