{"id":{"repo_id":"sdstate","oai_identifier":"oai:openprairie.sdstate.edu:etd-2537"},"canonical_url":"https://search.dev.ndltd.org/etd/sdstate/oai:openprairie.sdstate.edu:etd-2537","repository":{"repo_id":"sdstate","name":"South Dakota State University","base_url":"https://openprairie.sdstate.edu/do/oai/"},"display":{"title":"Lactoperoxidase System Effects on Escherichia Coli K-12 in the Manufacture of a High Moisture and High pH Cheese (Queso Fresco)","abstract":"<p><strong>The lactoperoxidase system, a naturally occurring antibacterial system in bovine milk, was evaluated as an additional food safety hurdle in a cheese that can support the growth of pathogenic microorganisms. Lactoperoxidase is not completely inactivated at pasteurization temperatures; however, its activity decreases with the increase in the processing temperature. Reduced lactoperoxidase activity results in the reduction of antibacterial effects on a gram negative coliform, Escherichia coli K-12. Lactoperoxidase activity was determined after activation and heat treatment at temperatures ranging from 62.8 to 76.7°C for 19 s. Though measurable activity was found at 73.9°C and below, minimum High Temperature Short Time pasteurization resulted in at least a 3 0% reduction in lactoperoxidase activity. For cheese making trials, milk was processed at 72.5 ± 0.5 °C for 19 s to satisfy the regulatory requirements for pasteurization. Eighteen lots of Queso Fresco, a soft variety of Mexican cheese, were manufactured after the inoculation of the processed milk with Escherichia coli K-12 ATCC 23716 at high and low inoculum levels (> 100,000 and </strong></p>","abstract_html":"&lt;p&gt;&lt;strong&gt;The lactoperoxidase system, a naturally occurring antibacterial system in bovine milk, was evaluated as an additional food safety hurdle in a cheese that can support the growth of pathogenic microorganisms. Lactoperoxidase is not completely inactivated at pasteurization temperatures; however, its activity decreases with the increase in the processing temperature. Reduced lactoperoxidase activity results in the reduction of antibacterial effects on a gram negative coliform, Escherichia coli K-12. Lactoperoxidase activity was determined after activation and heat treatment at temperatures ranging from 62.8 to 76.7°C for 19 s. Though measurable activity was found at 73.9°C and below, minimum High Temperature Short Time pasteurization resulted in at least a 3 0% reduction in lactoperoxidase activity. For cheese making trials, milk was processed at 72.5 ± 0.5 °C for 19 s to satisfy the regulatory requirements for pasteurization. Eighteen lots of Queso Fresco, a soft variety of Mexican cheese, were manufactured after the inoculation of the processed milk with Escherichia coli K-12 ATCC 23716 at high and low inoculum levels (&gt; 100,000 and &lt;/strong&gt;&lt;/p&gt;","abstract_has_math":false,"creators":["Bangalore, Raju S."],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis - University Access Only","degree_discipline":"Dairy Science","degree_department":null,"school":null,"contributors":["David R. Henning"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1997,"date_issued":"1997-01-01T08:00:00Z","date_published":"1997-01-01T08:00:00Z","updated_at":"2026-07-24T04:29:15Z","subjects":["Dairy Science"],"languages":["en"],"rights":["<p>In Copyright - Non-Commercial Use Permitted<br /><a href=\"http://rightsstatements.org/vocab/InC-NC/1.0/\">http://rightsstatements.org/vocab/InC-NC/1.0/</a></p>"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://openprairie.sdstate.edu/etd/1532","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["David R. 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Lactoperoxidase is not completely inactivated at pasteurization temperatures; however, its activity decreases with the increase in the processing temperature. Reduced lactoperoxidase activity results in the reduction of antibacterial effects on a gram negative coliform, Escherichia coli K-12. Lactoperoxidase activity was determined after activation and heat treatment at temperatures ranging from 62.8 to 76.7°C for 19 s. Though measurable activity was found at 73.9°C and below, minimum High Temperature Short Time pasteurization resulted in at least a 3 0% reduction in lactoperoxidase activity. For cheese making trials, milk was processed at 72.5 ± 0.5 °C for 19 s to satisfy the regulatory requirements for pasteurization. Eighteen lots of Queso Fresco, a soft variety of Mexican cheese, were manufactured after the inoculation of the processed milk with Escherichia coli K-12 ATCC 23716 at high and low inoculum levels (> 100,000 and </strong></p>"]},{"key":"dc:title","label":"Title","values":["Lactoperoxidase System Effects on Escherichia Coli K-12 in the Manufacture of a High Moisture and High pH Cheese (Queso Fresco)"]}]}],"canonical_facts":{"dc:contributor":["David R. Henning"],"dc:creator":["Bangalore, Raju S."],"dc:date.available":["2017-08-14T07:00:00Z"],"dc:description.abstract":["<p><strong>The lactoperoxidase system, a naturally occurring antibacterial system in bovine milk, was evaluated as an additional food safety hurdle in a cheese that can support the growth of pathogenic microorganisms. Lactoperoxidase is not completely inactivated at pasteurization temperatures; however, its activity decreases with the increase in the processing temperature. Reduced lactoperoxidase activity results in the reduction of antibacterial effects on a gram negative coliform, Escherichia coli K-12. Lactoperoxidase activity was determined after activation and heat treatment at temperatures ranging from 62.8 to 76.7°C for 19 s. Though measurable activity was found at 73.9°C and below, minimum High Temperature Short Time pasteurization resulted in at least a 3 0% reduction in lactoperoxidase activity. For cheese making trials, milk was processed at 72.5 ± 0.5 °C for 19 s to satisfy the regulatory requirements for pasteurization. Eighteen lots of Queso Fresco, a soft variety of Mexican cheese, were manufactured after the inoculation of the processed milk with Escherichia coli K-12 ATCC 23716 at high and low inoculum levels (> 100,000 and </strong></p>"],"dc:identifier":["https://openprairie.sdstate.edu/etd/1532"],"dc:language":["en"],"dc:rights":["<p>In Copyright - Non-Commercial Use Permitted<br /><a href=\"http://rightsstatements.org/vocab/InC-NC/1.0/\">http://rightsstatements.org/vocab/InC-NC/1.0/</a></p>"],"dc:subject":["Dairy Science"],"dc:title":["Lactoperoxidase System Effects on Escherichia Coli K-12 in the Manufacture of a High Moisture and High pH Cheese (Queso Fresco)"],"thesis:degree_discipline":["Dairy Science"],"thesis:degree_level":["Thesis - University Access Only"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T04:29:15Z"}