Demonstration of Escherichia coli Inactivation in Sterile Physiological Saline under High Pressure (HP) Phase Transition Conditions and Analysis of Probable Contribution of HP Metastable Positions Using Model Solutions and Apple Juice

Abstract

It was demonstrated that the inactivation of high pressure (HP) treatment on Escherichia coli survival in sterile physiological saline (SPS) was influenced by the treatment conditions: unfrozen, frozen-thawed and fully frozen (phase transition). In order to probe the enhanced phase transition microbial destruction, vibration effects of phase transition position were created and discussed. Test samples were placed in HP chamber for treatment (150/240/330 MPa, no holding time) at room temperature and a special cooling device was used to maintain the phase transition conditions. Results showed that the phase transition from ice I to ice III of frozen SPS could be realized based on the cooling of a 20% sodium chloride solution. HP treatment under fully frozen conditions produced the best lethal effect compared to unfrozen and freeze-thaw samples. Vibration tests were carried out by using model solutions and apple juice to explore the behavior of phase transition. A synchronous and advance phase transition of internal apple juice was realized, respectively, by using pure water and 5% sodium chloride solution as external vibration sources, and the advance phase transitions of external pure water were realized by using 5% sodium chloride solution and 5% glucose solution as internal vibration sources.

Frozen-Phase High-Pressure Destruction Kinetics of Escherichia coli as Influenced by Application Mode, Substrate, and Enrichment Medium

“…The state change and different phase transition point of the support medium have been reported in many studies, including those on carrot juice, milk, grape juice, apple juice [ 9 , 10 , 29 , 30 ]. The different phase point in a different support matrix implied the difference of inactivation efficiency with HP treatment, and the low pH matrix and frozen temperature were helpful to improve the inactivation efficiency in many reports [ 26 , 31 ]. The temperature change was important factors of the inactivation efficiency.…”

Multi-Response Optimization of Pyrrolizidine Alkaloids Removal from Chrysanthemum morifolium by High-Pressure Extraction

“…The independent variables (factors) were pressure (X 1 ), number of cycles (X 2 ) and acetic acid (AcOH) concentration (X 3 ). The range of independent variables were listed in Table 1 , which were determined based on previous studies [ 13 , 20 ] and actual production costs [ 22 ]. The dependent variables (responses) were the RME of PAs (Y 1 ) and the RTE of chlorogenic acid (Y 2 ), luteolin-7-β-D-glucopyranoside (Y 3 ), 3,5-dicaffeyl quinic acid (Y 4 ) and total flavonoids (Y 5 ).…”

Recent Progress in the Synergistic Bactericidal Effect of High Pressure and Temperature Processing in Fruits and Vegetables and Related Kinetics

“… The volume of ice crystals (pure water) in individual phases; the letter V in the figure is the corresponding volume of different phases (g/cm 3 ). The image was drawn concerning the data of Bridgman et al [ 88 ] and Xiao et al [ 89 ]. …”