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Survival and growth of Listeria monocytogenes on romaine lettuce as influenced by crisping and misting
Descriptive
TitleInfo
Title
Survival and growth of Listeria monocytogenes on romaine lettuce as influenced by crisping and misting
Name
(type = personal)
NamePart
(type = family)
Guo
NamePart
(type = given)
Mengqi
NamePart
(type = date)
1992-
DisplayForm
Mengqi Guo
Role
RoleTerm
(authority = RULIB)
author
Name
(type = personal)
NamePart
(type = family)
Matthews
NamePart
(type = given)
Karl
DisplayForm
Karl Matthews
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
chair
Name
(type = personal)
NamePart
(type = family)
Schaffner
NamePart
(type = given)
Donald W.
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Donald W. Schaffner
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
internal member
Name
(type = personal)
NamePart
(type = family)
Chikindas
NamePart
(type = given)
Michael
DisplayForm
Michael Chikindas
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
internal member
Name
(type = corporate)
NamePart
Rutgers University
Role
RoleTerm
(authority = RULIB)
degree grantor
Name
(type = corporate)
NamePart
Graduate School - New Brunswick
Role
RoleTerm
(authority = RULIB)
school
TypeOfResource
Text
Genre
(authority = marcgt)
theses
OriginInfo
DateCreated
(qualifier = exact)
2017
DateOther
(qualifier = exact);
(type = degree)
2017-01
CopyrightDate
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(qualifier = exact)
2017
Place
PlaceTerm
(type = code)
xx
Language
LanguageTerm
(authority = ISO639-2b);
(type = code)
eng
Abstract
(type = abstract)
Listeria monocytogenes is a foodborne pathogen of particular concern for manufacturers of refrigerated fresh produce because of its wide distribution in the environment and its ability to grow at refrigeration temperature. Approximately, two-thirds of supermarkets implement crisping and misting to enhance product appearance and quality. Based on the FDA food code, water used for soaking, submersion, hydrating, or crisping does not need to contain chemical sanitizers. When product is submerged in water, cross-contamination may occur. Therefore, the impact of crisping in water with and without sanitizer was investigated. The study was coupled with determining the influence of misting on growth and survival of L. monocytogenes. Romaine lettuce was inoculated with L. monocytogenes cocktail to achieve initial population of ca. 5.5 log CFU/g, heads were submerged in tap water or tap water containing electrolyzed water for 5 min and then held at 5 oC for 2 h to crisp. Half of the crisped lettuce heads were placed in a refrigerated commercial display cabinet and misted for 24 h. Lettuce was then transferred to a refrigerator (5 oC and 15 oC) and held for 7 days. The population of L. monocytogenes and psychrotrophic bacteria was determined at day 0, 1, 4, and 7 for each treatment and temperature. The results showed that crisping in electrolyzed water significantly reduced (P<0.05) the population of L. monocytogenes by 2.93 log compared to tap water alone (1.32 log reduction). An additional 1 log reduction in population of L. monocytogenes occurred after 24 h misting. The population of L. monocytogenes remained relatively constant during 7 days of refrigerated storage. There was no significant difference in population of L. monocytogenes on lettuce held at 5oC or 15oC. Crisping and misting treatments reduced the population of psychrotrophic bacteria on lettuce. The psychrotrophic bacteria population was greater on lettuce held at 15oC, reaching 6.99-7.54 log CFU/g after 7 days. Results of the present study suggest that crisping treatment, especially with electrolyzed water sanitizer significantly reduced the population of L. monocytogenes on romaine lettuce. Misting also had a negative effect on the survival and growth of L. monocytogenes. Based on the methods used in the present study, the practice of crisping with a commercial sanitizer and misting may enhance the microbial safety of commodities sold at retail supermarkets.
Subject
(authority = RUETD)
Topic
Food Science
RelatedItem
(type = host)
TitleInfo
Title
Rutgers University Electronic Theses and Dissertations
Identifier
(type = RULIB)
ETD
Identifier
ETD_7784
PhysicalDescription
Form
(authority = gmd)
electronic resource
InternetMediaType
application/pdf
InternetMediaType
text/xml
Extent
1 online resource (ix, 54 p. : ill.)
Note
(type = degree)
M.S.
Note
(type = bibliography)
Includes bibliographical references
Subject
(authority = ETD-LCSH)
Topic
Listeria monocytogenes
Subject
(authority = ETD-LCSH)
Topic
Lettuce--Microbiology
Note
(type = statement of responsibility)
by Mengqi Guo
RelatedItem
(type = host)
TitleInfo
Title
Graduate School - New Brunswick Electronic Theses and Dissertations
Identifier
(type = local)
rucore19991600001
Location
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(displayLabel = Rutgers, The State University of New Jersey)
NjNbRU
Identifier
(type = doi)
doi:10.7282/T35D8V96
Genre
(authority = ExL-Esploro)
ETD graduate
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Rights
RightsDeclaration
(ID = rulibRdec0006)
The author owns the copyright to this work.
RightsHolder
(type = personal)
Name
FamilyName
Guo
GivenName
Mengqi
Role
Copyright Holder
RightsEvent
Type
Permission or license
DateTime
(encoding = w3cdtf);
(qualifier = exact);
(point = start)
2016-12-21 01:17:30
AssociatedEntity
Name
Mengqi Guo
Role
Copyright holder
Affiliation
Rutgers University. Graduate School - New Brunswick
AssociatedObject
Type
License
Name
Author Agreement License
Detail
I hereby grant to the Rutgers University Libraries and to my school the non-exclusive right to archive, reproduce and distribute my thesis or dissertation, in whole or in part, and/or my abstract, in whole or in part, in and from an electronic format, subject to the release date subsequently stipulated in this submittal form and approved by my school. I represent and stipulate that the thesis or dissertation and its abstract are my original work, that they do not infringe or violate any rights of others, and that I make these grants as the sole owner of the rights to my thesis or dissertation and its abstract. I represent that I have obtained written permissions, when necessary, from the owner(s) of each third party copyrighted matter to be included in my thesis or dissertation and will supply copies of such upon request by my school. I acknowledge that RU ETD and my school will not distribute my thesis or dissertation or its abstract if, in their reasonable judgment, they believe all such rights have not been secured. I acknowledge that I retain ownership rights to the copyright of my work. I also retain the right to use all or part of this thesis or dissertation in future works, such as articles or books.
RightsEvent
DateTime
(encoding = w3cdtf);
(qualifier = exact);
(point = start)
2017-01-31
DateTime
(encoding = w3cdtf);
(qualifier = exact);
(point = end)
2017-08-02
Type
Embargo
Detail
Access to this PDF has been restricted at the author's request. It will be publicly available after August 2nd, 2017.
Copyright
Status
Copyright protected
Availability
Status
Open
Reason
Permission or license
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Technical
RULTechMD
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ETD
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windows xp
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