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High Pressure Processing (high + pressure_processing)
Selected AbstractsHigh Pressure Processing , a Database of Kinetic InformationCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 8 2008R. Buckow Abstract Hydrostatic high pressure technology is relatively new to food industry and is more and more considered as an alternative to traditional preservation methods like heat processing. The inactivation of bacteria, spores, viruses and enzymes has been demonstrated in numerous papers, and various schemes for modelling the experimental inactivation data have been suggested. Although there are similarities to heat inactivation kinetics it is generally agreed that the heat process safety assessment with its typical indicator organisms cannot simply be transferred to high pressure treatment. In this paper a database is introduced which aims at the comparison of published kinetic high pressure inactivation data by using suitable mathematical modelling tools. For the sake of clarity, the functional associations of pressure, temperature and exposure time is presented by means of pressure-temperature diagrams (pT -diagrams), which show pressure-temperature combinations yielding to a desired reaction (e.g. inactivation) rate constant. Thus, the database software was particularly designed to enable the user to call up pressure-temperature dependent function equations for a number of micro-organisms, enzymes and food constituents and to visualize them in pT -diagrams for predetermined treatment times or as kinetics under predetermined p - T conditions. In addition, the database also features a simple calculator tool which allows the user to make an entry in three of the four process conditions (pressure level, temperature level, inactivation level, dwell time) and calculate the remaining forth process condition. The database is accessible through the internet and is continuously updated on the basis of the most recent publications and own experimental data. [source] Combined Carbon Dioxide and High Pressure Inactivation of Pectin Methylesterase, Polyphenol Oxidase, Lactobacillus plantarum and Escherichia coliJOURNAL OF FOOD SCIENCE, Issue 2 2002H. Corwin ABSTRACT: High pressure processing (HPP) and CO2have both been shown to increase food product shelf-life. CO2 was added at approximately 0.2 molar % to solutions processed at 500 to 800 MPa in order to further inactivate pectin methylesterase (PME), polyphenol oxidase (PPO), L. plantarum ATCC 8014, and E. coli K12. An interaction was found between CO2 and pressure at 25 °C and 50 °C for PME and PPO, respectively. Activity of PPO was decreased by CO2 at all pressure treatments. The interaction between CO2 and pressure was significant for L. plantarum with a significant decrease in survivors due to the addition of CO2 at all pressures studied. No significant effect on E. coli survivors was seen with CO2 addition. [source] Efficacy of Pressure-Assisted Thermal Processing, in Combination with Organic Acids, against,Bacillus amyloliquefaciens,Spores Suspended in Deionized Water and Carrot PureeJOURNAL OF FOOD SCIENCE, Issue 1 2010Wannasawat Ratphitagsanti ABSTRACT:, Effect of organic acids (acetic, citric, and lactic; 100 mM, pH 5) on spore inactivation by pressure-assisted thermal processing (PATP; 700 MPa and 105 °C), high pressure processing (HPP; 700 MPa, 35 °C), and thermal processing (TP; 105 °C, 0.1 MPa) was investigated.,Bacillus amyloliquefaciens,spores were inoculated into sterile organic acid solutions to obtain a final concentration of approximately 1.3 × 108 CFU/mL.,B. amyloliquefaciens,spores were inactivated to undetectable levels with or without organic acids after 3 min PATP holding time. At a shorter PATP treatment time (approximately 2 min), the inactivation was greater when spores were suspended in citric and acetic acids than in lactic acid or deionized water. Presence of organic acids during PATP resulted in 33% to 80% germination in the population of spores that survived the treatment. In contrast to PATP, neither HPP nor TP, for up to 5 min holding time with or without addition of organic acids, was sporicidal. In a separate set of experiments, carrot puree was tested, as a low-acid food matrix, to study spore recovery during extended storage following PATP. Results showed that organic acids were effective in inhibiting spore recovery in treated carrot puree during extended storage (up to 28 d) at 32 °C. In conclusion, addition of some organic acids provided significant lethality enhancement (P,< 0.05) during PATP treatments and suppressed spore recovery in the treated carrot puree. [source] Inactivation of Campylobacter jejuni by high hydrostatic pressureLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2004E.B. Solomon Abstract Aims:, To investigate the response of Campylobacter jejuni ATCC 35919 and 35921 to high pressure processing (HPP) while suspended in microbiological media and various food systems. Methods and Results:,Campylobacter jejuni 35919 and 35921 were subjected to 10-min pressure treatments between 100 and 400 MPa at 25°C suspended in Bolton broth, phosphate buffer (0·2 m, pH 7·3), ultra-high temperature (UHT) whole milk, UHT skim milk, soya milk and chicken pureé. The survivability of C. jejuni was further investigated by inoculated pack studies. HPP at 300,325 MPa for 10 min at 25°C was sufficient to reduce viable numbers of both strains to below detectable levels when cells were pressurized in Bolton broth or phosphate buffer. All food products examined offered a protective effect in that an additional 50,75 MPa was required to achieve similar levels of inactivation when compared with broth and buffer. Inoculated pack studies showed that the survivability of C. jejuni following pressurization improved with decreasing post-treatment storage temperature. Significance and Impact of the Study:, These data demonstrated that HPP at levels of ,400 MPa, can inactivate C. jejuni in both model and food systems. [source] | ||||||||||