Thesis
Ultra high pressure inactivation of Saccharomyces cerevisiae and Listeria innocua on fruit
Master of Science (MS), Washington State University
2004
Handle:
https://hdl.handle.net/2376/270
Abstract
Shelf stable fruit preserves and pie fillings are traditionally stabilized with thermal processes to ensure food safety and prolonged shelf life. Fruit products exposed to high temperatures frequently present a cooked flavor, losing desirable texture, color, and nutrient quality. Nonthermal ultra high pressure processing exhibits the potential of achieving a “fresh like” quality fruit product desired by consumers while inactivating common pathogenic and spoilage microorganisms. The objective of the current research was to investigate decimal reduction times obtained with selected ultra high pressure treatments. High pressure survivor curves for Saccharomyces cerevisiae and Listeria innocua inoculated on apples and blueberries were determined at 300 or 375 MPa, respectively. Saccharomyces cerevisiae D-values ranged from 19.7 s on apples to 22.4 s on blueberries. D-values for Listeria innocua ranged from 67.1 s on apples to 46.7 s on blueberries. High pressure D-values of Saccharomyces cerevisiae and Listeria innocua were also evaluated in commercial apple sauce with adjusted soluble solids concentrations ranging from 13% to 60%. D-values for Saccharomyces cerevisiae in apple sauce treated with 300 MPa are 26.3, 29.9 and 46.5 s at 13, 20 and 30% of soluble solids, respectively. D-values for Listeria innocua in apple sauce treated with 375 MPa are 40.2, 55.2 and 120.6 s at 13, 20 and 30% of soluble solids, respectively. Ultra high pressure treatment of commercial apple sauce inoculated with Listeria innocua and Saccharomyces cerevisiae adjusted to 40, 50 or 60% sucrose concentrations reduced the initial inocula of 107 to 106 less than 1 log. Sucrose concentrations greater than 30% provide a baroprotective effect on microbial inhibition by ultra high pressure treatment.
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Details
- Title
- Ultra high pressure inactivation of Saccharomyces cerevisiae and Listeria innocua on fruit
- Creators
- Maite Andrea Chauvin
- Contributors
- Barry Grant Swanson (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Food Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Identifiers
- 99900525158201842
- Language
- English
- Resource Type
- Thesis