Inactivation of Escherichia coli O157:H7 on Orange Fruit Surfaces and in Juice Using Photocatalysis and High Hydrostatic Pressure
- Authors
- Yoo, Sungyul; Ghafoor, Kashif; Kim, Jeong Un; Kim, Sanghun; Jung, Bora; Lee, Dong-Un; Park, Jiyong
- Issue Date
- Jun-2015
- Publisher
- INT ASSOC FOOD PROTECTION
- Citation
- JOURNAL OF FOOD PROTECTION, v.78, no.6, pp 1098 - 1105
- Pages
- 8
- Journal Title
- JOURNAL OF FOOD PROTECTION
- Volume
- 78
- Number
- 6
- Start Page
- 1098
- End Page
- 1105
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/9505
- DOI
- 10.4315/0362-028X.JFP-14-522
- ISSN
- 0362-028X
1944-9097
- Abstract
- Nonpasteurized orange juice is manufactured by squeezing juice from fruit without peel removal. Fruit surfaces may carry pathogenic microorganisms that can contaminate squeezed juice. Titanium dioxide-UVC photocatalysis (TUVP), a nonthermal technique capable of microbial inactivation via generation of hydroxyl radicals, was used to decontaminate orange surfaces. Levels of spot-inoculated Escherichia coli O157:H7 (initial level of 7.0 log CFU/cm(2)) on oranges (12 cm(2)) were reduced by 4.3 log CFU/ml when treated with TUVP (17.2 mW/cm(2)). Reductions of 1.5, 3.9, and 3.6 log CFU/ml were achieved using tap water, chlorine (200 ppm), and UVC alone (23.7 mW/cm(2)), respectively. E. coli O157:H7 in juice from TUVP (17.2 mW/cm(2)) treated oranges was reduced by 1.7 log CFU/ml. After orange juice was treated with high hydrostatic pressure (HHP) at 400 MPa for 1 min without any prior fruit surface disinfection, the level of E. coli O157:H7 was reduced by 2.4 log CFU/ml. However, the E. coli O157:H7 level in juice was reduced by 4.7 log CFU/ml (to lower than the detection limit) when TUVP treatment of oranges was followed by HHP treatment of juice, indicating a synergistic inactivation effect. The inactivation kinetics of E. coli O157:H7 on orange surfaces followed a biphasic model. REP treatment did not affect the pH, degrees Brix, or color of juice. However, the ascorbic acid concentration and pectinmethylesterase activity were reduced by 35.1 and 34.7%, respectively.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - ETC > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.