Germination and Inactivation of Alicyclobacillus acidoterrestris Spores Induced by Moderate Hydrostatic Pressure
Barbara Sokołowska, Sylwia Skąpska, Monika Fonberg-Broczek, Jolanta Niezgoda, Izabela Porębska, Agnieszka Dekowska, Sylwester J. Rzoska Pol J Microbiol 2015; 64 (4): ICID: 1170291 Article type: Original article IC™ Value: 10.00
Abstract provided by Publisher
Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure.
Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50ºC for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log.
The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20ºC was 2.04 log, with only 0.61 log of spores being inactivated, while at 70ºC spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure.
When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode.
The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.