HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Nakai, S. Articles by Herreid, E. O. Search for Related Content PubMed Articles by Nakai, S. Articles by Herreid, E. O.

Spectrophotometric Determination of Protein in Milk¹

Department of Food Science, University of Illinois, Urbana

ABSTRACT

The spectrophotometric method of Haugaard and Damm (1) for estimating the protein content of skimmilk at wavelength 277 mµ was modified for raw and pasteurized milk, sterile concentrate, and cream as follows: Add 0.5 ml of butylamine to 0.5 ml of milk, heat to 65 C for 5 min, add 25 ml of a mixture of 0.3% each of disodium ethylenediamine—tetraacetate (EDTA) and sodium lauryl sulfate (SLS), add five drops of hydrochloric acid and filter. Add one drop of 30% sodium hydroxide solution and read the optical density at 280 mµ.

For milk changed by the Maillard-type reaction, add 0.5 ml of butylamine to 0.5 ml of milk, heat to 65 C and add two drops of sodium borohydride. The remainder of the procedure is the same.

Results for whole milk, sterile concentrated milk, and cream agreed with the Kjeldahl method.

¹ This work was supported by USPH RG EF 141.

² Post-doctorate Research Associate.