Inactivation of Alicyclobacillus acidoterrestris vegetative cells in model system, apple, orange and tomato juices by high hydrostatic pressure

Date

2003-08-01

Author

Alpas, Hami
Alma Uzuntuna, Leyla
BOZOGLU, F

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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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The objective of this study is to determine the effect of high hydrostatic pressure (HHP) on inactivation of Alicyclobacillus acidoterrestris vegetative cells in a model system (BAM broth) and in orange, apple and tomato juices. The shelf-life stability of pressurized juices is also studied. In general the viability loss was enhanced significantly as the level of pressure and temperature were increased ( P < 0.05). 4.70 log cycle reduction was obtained after pressurization at 350 MPa at 50 degrees C for 20 min in BAM broth whereas thermal treatment at 50 degrees C for 20 min caused only 1.13 log cycle inactivation showing the effectiveness of HHP treatment on inactivation. The D values for pressure ( 350 MPa at 50 degrees C) and temperature (50 degrees C) treatments were 4.37 and 18.86 min in BAM broth, respectively. All juices were inoculated with A. acidoterrestris cells to 10(6) c.f.u./ml and were pressurized at 350 MPa at 50 degrees C for 20 min. More than 4 log cycle reduction was achieved in all juices studied immediately after pressurization. The pressurized juices were also stored up to 3 weeks at 30 degrees C and the viable cell numbers of A. acidoterrestris in orange, apple and tomato juices were 3.79, 2.59 and 2.27 log cycles, respectively after 3 weeks. This study has indicated that A. acidoterrestris vegetative cells can be killed by HHP at a predictable rate even at temperatures at which the microorganism would normally grow.

Subject Keywords

Alicyclobacillus acidoterrestris, Apple juice, Hydrostatic pressure, Orange juice, Tomato juice

URI

https://hdl.handle.net/11511/31587

Collections

Graduate School of Social Sciences, Article