Synergistic combinations of high hydrostatic pressure and essential oils or their constituents and their use in preservation of fruit juices

• Published in: International journal of food microbiology 2013-01, Vol.161 (1), p.23-30
• Main Authors: Espina, Laura, García-Gonzalo, Diego, Laglaoui, Amin, Mackey, Bernard M., Pagán, Rafael
• Format: Article
• Language: English
• Subjects: Beverages; Biological and medical sciences; Citrus reticulata; Citrus sinensis; Colony Count, Microbial; Cyperus longus; Escherichia coli; Escherichia coli O157 - drug effects; Escherichia coli O157 - physiology; Escherichia coli O157:H7; Essential oils; Eucalyptus globulus; Food industries; Food microbiology; Food Preservation - methods; Fruit; Fundamental and applied biological sciences. Psychology; High hydrostatic pressure; Hydrostatic Pressure; Juniperus; Listeria monocytogenes; Listeria monocytogenes - drug effects; Listeria monocytogenes - physiology; Malus; Mentha pulegium; Microbial Viability - drug effects; Oils, Volatile - chemistry; Oils, Volatile - pharmacology; Rosmarinus officinalis; Sublethal injury; Synergistic effect; Time Factors
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2012.11.015

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 (175–400MPa for 20min) were combined with 200μL/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 log10 cycles of the initial cell populations in combination with HHP, and therefore showed outstanding synergistic effects. (+)-Limonene was also capable of inactivating 5 log10 cycles of the initial E. coli O157:H7 population in combination with HHP (300MPa for 20min) 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. ► Valuable synergistic effects were obtained when combining HHP and essential oils. ► Combined processes inactivated 5 log10 cycles of E. coli O157:H7 and L. monocytogenes. ► Addition of limonene would allow reducing treatment time and pressure. ► Limonene can improve preservation of fruit juices by high hydrostatic pressure.