Pulsed electric fields assisted microbial inactivation of S. cerevisiae cells by high pressure carbon dioxide
MetadataShow full item record
SubjectMicrobial inactivation; Pulsed electric fields; High pressure carbon dioxide; Combined treatment
The effect of pulsed electric field (PEF) pretreatments on the inactivation of microbial populations by high pressure carbon dioxide (HPCD) processing was studied. Saccharomyces cerevisiae cells suspended in McIlvaine buffer solutions were used in three different tests: a single PEF treatment, a single HPCD treatment and a combined PEF and HPCD treatment. Experiments were carried out testing the effects of different electric field strengths (6, 9 and 12 kV/cm) and energy inputs (10, 20 and 40 J/ml) on the microbial inactivation during the PEF pretreatment. Pressures of 8.0, 11.0 and 14.0 MPa and treatment times ranging from 3 to 30 min were applied during the HPCD treatment following the PEF pretreatment stage, with the aim of investigating the synergistic effect of the combined treatment. For comparison, inactivation curves of the microorganism during the single PEF and HPCD treatments were determined. Results showed that treating the cell suspensions only with PEF, the maximum inactivation level that could be achieved was 0.35 log-cycles after a treatment at 12 kV/cm and 20 J/ml. On the other hand, when yeast cells were treated only with HPCD, the maximum inactivation level detected was 1.79 log-cycles treating the sample at a pressure of 8.0 MPa for 3 min. With increasing the pressure up to 14.0 MPa and the treatment time up to 30 min no further increase of cells inactivation was detected. A completely different behavior was observed utilizing the combination of PEF and HPCD treatments. In this case, with increasing the field strength and the electrical energy input in the selected range, a remarkable increase of the inactivation after the combined treatment was detected. At a certain intensity of the PEF pretreatment, the use of more severe CO pressures and HPCD processing time did not determine any further reduction of the microbial population. The inactivation kinetics obtained after the combined treatment were fitted with the Peleg equation.
Showing items related by title, author, creator and subject.
Microbial Inactivation Kinetics during High-Pressure Carbon Dioxide Treatment: Nonlinear Model for the Combined Effect of Temperature and Pressure in Apple Juice Ferrentino G; Ferrari G; Poletto M; Balaban MO (BLACKWELL PUBLISHING, 2008)Isobaric and isothermal semi-logarithmic survival curves of natural microflora in apple juice treated with high-pressure carbon dioxide at 7, 13, and 16 MPa pressures and 35, 50, and 60 degrees C temperatures were fitted ...
In Situ Raman Quantification Of Dissolution Kinetics Of Carbon Dioxide In Liquid Solutions During A High Pressure And Ultrasound Treatment For The Inactivation Of Saccharomyces Cerevisiae Ferrentino, G; Schuster, J; Braeuer, A; Spilimbergo, S (Elsevier, 2016)A Raman based optical approach is presented to enable the remote, temporally resolved and in situ quantification of the amount of carbon dioxide (CO2) dissolved in distilled water and coconut water during a high pressure ...
Validation of a mathematical model for predicting high pressure carbon dioxide inactivation kinetics of Escherichia coli spiked on fresh cut carrot Ferrentino G; Calliari N; Bertucco A; Spilimbergo S (2014)Inactivation kinetics of Escherichia coli spiked on fresh cut carrot and exposed to high pressure carbon dioxide (HPCD) treatment at several conditions of pressure (6, 8, 10, and 12 MPa) and two conditions of temperature ...