Optimization of Sanitizing Process Using Heat Against Bacteria Asaia bogorensis

1. INSTITUTE OF CHEMICAL TECHNOLOGY, PRAGUE Department of Food Preservation and Meat Technology Optimization of Sanitizing Process Using Heat Against Bacteria Asaia bogorensis Petra Klodnerová, MSc Supervisor: Miroslav Čeřovský, MSc, PhD

2. Asaia bogorensis Fig. 2: Microscopic picture of cells. Fig. 1: Colonies on PCA Agar.

3. Aim of Research Heat Resistance of A. bogorensis • technological problem • Asaia bogorensis = new unusual spoilage organism of still fruit-flavored bottled water • sanitizing process optimalization, using heat • find D and zvalue

4. 3.5 3 2.5 2 Log D 1.5 1 z 0.5 7 Temperature 6 5 4 Log N 3 2 D 1 0 2 4 6 8 10 12 14 Time Thermal Inactivation ParametersD and z value Fig.3: Survivor curve Fig.4: Thermal-death-time curve

5. 10 mm 12 mm 1.9 mm Holder of capillary tube 41 mm 135 mm Teflon piston 1.5 mm Metal capillary tube Silicon gasket Methods and Instruments Fig. 6: Equipment for capillary tube method Fig. 5: TDT tube method

6. Experimental Procedure sample preparation – suspension cultivated 96 hr, 30 °C TDT and capillary tube filling with sample tube submersion in heating water bath tube immersion in ice-water bath heated samplemicrobial analysis construction of microbial survivor curve and thermal-death-time curve D and zvalue

7. D and z Values of Asaia bogorensis in Nutrient Broth

8. Comparison of TDT Tube Method and Capillary Tube Method

9. D50 Value of Asaia bogorensis in McIlvaine Buffer

10. CONCLUSIONS • A. bogorensisis more heat resistant after cultivation at 30 °C than at 25 °C. • A. bogorensis is sensitive to relatively low temperatures (D55= 0,6 min). • Heat resistance of A. bogorensis at 50 °C is the least at pH 8. • Possibilityof heat treatment usage for optimalization of sanitizing process, whereas thermally sensitive components of equipment are not damaged.

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