عنوان

A RAPID LABORATORY TEST TO DEMONSTRATE THERMAL INACTIVATION OF EXOTIC NEWCASTLE DISEASE VIRUS IN TURKEY BREAST

Number

TLpq303482170

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

A RAPID LABORATORY TEST TO DEMONSTRATE THERMAL INACTIVATION OF EXOTIC NEWCASTLE DISEASE VIRUS IN TURKEY BREAST

General Material Designation

[Thesis]

First Statement of Responsibility

R. M. Davis

Name of Publisher, Distributor, etc.

Iowa State University

Date of Publication, Distribution, etc.

1987

Specific Material Designation and Extent of Item

122-122 p.

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

Iowa State University

Text preceding or following the note

1987

Text of Note

Thermal inactivation characteristics of Newcastle disease virus (NDV) were defined in turkey breast spiked to usd10\sp8usd virus per gram. Five strains, including mesogenic, velogenic and exotic NDV, were compared for loss of infectivity at usd56\sp\circ{\rm C}.usd Roakin and Fontana strains were more stable than Texas GB, San Juan or Parrot Project viruses. The thermal death time curve for Roakin strain NDV was defined over the temperature range 56 to usd68.8\sp\circ{\rm C}.usd Based on time required to inactivate virus at various temperatures, the values usd{\rm F\sb{68.8\sp\circ C}} = 5.0usd min and z = usd8.9\sp\circ{\rm C}usd were calculated. Thirty adult market turkeys were inoculated with the Fontana strain of exotic NDV. Pre-inoculation hemagglutination inhibition antibody titers did not exceed 1:16. The combined intraocular (IO), intravenous (IV) and intra-muscular routes of inoculation were more effective than IO or IO plus IV. Virus was demonstrated in 12 of the 30 turkey breasts. Viremic turkey breast tissue was thermally processed under laboratory conditions which duplicated the heat exposure of the center of whole breasts heated by a proposed commercial process. No virus was recovered from any of the thermally processed viremic turkey breasts. Acid phosphatase (ACP) activity of turkey breast was determined for temperature/time treatments which inactivated NDV. At usd56\sp\circ{\rm C}/140usd min and usd60\sp\circ{\rm C}/49usd min, the ACP activity was more stable to heating than was the ACP activity at usd64\sp\circ{\rm C}/17.2usd min and usd68.8\sp\circ{\rm C}/5.0usd min. The ACP was more extensively inactivated by proposed commercial processing conditions than it was by any of the temperature/time treatments which inactivated NDV. Therefore, laboratory analysis which demonstrates that ACP activity of thermally processed turkey breast falls below a threshold level indicates that NDV has been destroyed. The threshold ACP activity level can be adjusted to change the safety margin. In this model system, adequate processing can be demonstrated regardless of the specific thermal process used. The ACP test method, based on 2,6 dibromoquinone chloride colorimetry, was shown to be subject to both false positive and false negative reactions with some phenolics present in spices and flavorings.

Biological sciences

Veterinary services

R. M. Davis

Electronic name

p

[Thesis]

276903

a

Y