Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/22/2006
Publication Date: 6/25/2006
Citation: Geveke, D.J., Jin, Z.T., Zhang, H.Q. 2006. Pasteurization of liquid egg whites using combined ultraviolet light and thermal treatments [abstract]. International Food Technologists. Paper No. 017-07.
Technical Abstract: The USDA’s FSIS desires research on different pasteurization processes to continue to provide safe liquid egg products for foodservice and industry. It has consistently been reported in the literature that thermal treatment of egg whites in the pasteurization range damages the functional properties. Ultraviolet light (UV) processing has recently been approved by the FDA for pasteurizing juices, but little research has been performed using this technique with liquid egg. The objective of this study was to conduct combined UV and thermal inactivation tests with E. coli in liquid egg white. E. coli ATCC 23716 was inoculated into liquid egg white. The whites were processed using a simple UV apparatus consisting of a low pressure mercury lamp surrounded by a coil of UV transparent tubing. Whites were pumped through the tubing at 21 C. Treatment times of 50 s and 60 s were investigated. Thermal inactivation tests at 56 C were immediately performed after UV processing. UV processing alone for 50 and 60 s reduced E. coli by 1.9 and 2.5 log. The D values of E. coli at 56 C in the unprocessed and UV processed egg whites averaged 0.46 min and were not statistically different indicating that the effects of UV and thermal treatments are additive. The combination of a 50 s, room temperature UV treatment and a 3 min, 56 C thermal treatment reduced E. coli by 6 log, whereas a 4 min, 56 C thermal treatment was required to achieve the same reduction. UV treatment at room temperature can significantly reduce the required thermal treatment to pasteurize liquid egg whites. This hurdle treatment may produce whites with improved functional properties.