Heat Stability of Bovine Milk Immunoglobulins and Their Ability to Bind Lactococci as Determined by an ELISA

Authors

  • Z. USTUNOL,

    1. Author Ustunol is with the Dept. of Food Science & Human Nutrition, Michigan State Univ., East Lansing, MI 48824. Author Sypien, formerly with Michigan State Univ., is now with Gordon Food Service, 333 Fiftieth St. S.W., P.O. Box 1787, Grand Rapids, MI 49501.
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  • C. SYPIEN

    1. Author Ustunol is with the Dept. of Food Science & Human Nutrition, Michigan State Univ., East Lansing, MI 48824. Author Sypien, formerly with Michigan State Univ., is now with Gordon Food Service, 333 Fiftieth St. S.W., P.O. Box 1787, Grand Rapids, MI 49501.
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  • Michigan Agricultural Experiment Station is acknowledged for partial support of this research. We express gratitude to Dr. J. Pestka for the use of the laboratory facilities and for expertise advice on the ELISA experiments, and to Dr. J. Whalon for expertise advice with LSM. Also, we express gratitude to Dr C.L. Hicks for critical review of the manuscript.

ABSTRACT

Immunoglobulins obtained from bovine colostrum were heat treated at 70, 75, 80 and 85°C for 0-90 min. An ELISA was developed to determine the susceptibility of lactococci to bind heat treated IgG, IgM and IgA. IgA was the most heat sensitive of the immunoglobulins. Treatment at 80°C for 25 min completely inactivated IgA as evidenced by the inability of lactococci to bind IgA. IgM was completely inactivated upon heating to 85°C for 20 min whereas IgG was completely inactivated at 85°C after 30 min. Laser Scanning Microscopy verified results with ELISA. Severe thermal treatment is needed to reduce immunogenicity of bovine milk to prevent lactococcal agglutination.

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