Lactoperoxidase System Effects on Escherichia Coli K-12 in the Manufacture of a High Moisture and High pH Cheese (Queso Fresco)

<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>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Dairy Science

Year dc:date.available

1997

Author dc:creator

• Bangalore, Raju S.

Contributors dc:contributor

• David R. Henning

• Dairy Science

Statement 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>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/1532

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-2537