Continuous Flow Analysis of Non-Casein Protein in Milk

Author

Robert Steven White, Utah State University

Date of Award:

5-1972

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Sciences

Committee Chair(s)

Gary H. Richardson

Committee

Gary H. Richardson

Committee

C. A. Ernstrom

Committee

J. C. Batty

Committee

R. C. Anderson

Abstract

The Technicon AutoAnalyzer II was evaluated for automatic quantitation of non-casein protein (NCP) in milk. The Lowry method for colorimetric measurement of proteins was adapted to the automated method and found to be accurate in the determination of non-casein protein in milk. The automated Lowry method obeyed Beer's law. Casein content was calculated by difference between total protein determined by infrared milk analysis (IRMA) and non-casein protein. In the analysis of twenty-five replicate milk samples, the standard deviation was 0.32 and the coefficient of variability was 0.90. The casein content as a percentage of total protein in the milk of cows in the Utah State University dairy herd was found to vary from 41.0 to 81.3%. The automated or continuous flow method was affected by as little as 0.05% (w/w) mercuric chloride, a chemical preservative used in milk, whereas potassium dichromate and formaldehyde had insignificant effects upon the assay.

Checksum

916bf819ed31d1667b39889761daaa78

Recommended Citation

White, Robert Steven, "Continuous Flow Analysis of Non-Casein Protein in Milk" (1972). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 5124.
https://digitalcommons.usu.edu/etd/5124