The Nitrogen Distribution in Dried Milk

Abstract

Du r i n g an investigation of the bak­ ing quality of dried skim milk it became desirable to know whether the nitrogen distribution differed from that of normal fresh skim milk. The sam­ ples analyzed were made by the spray process.* 8 Most of the milk had been preheated before drying. The samples were stored in sealed containers at just above freezing temperature. The methods of analysis were mainly those of Rowland (1) and Menefee et al. (2) . The samples for each de­ termination were weighed out in the dry form, reconstituted with ten times their weight of water, and allowed to stand about one hour before the analy­ sis was continued. In order to increase the accuracy, macro methods were and 200 ml. of the filtrates were used for the nitrogen determination by the regular macro Kjeldahl method. The albumin-plus-globulin fraction was de­ termined by difference after repeating the non-casein nitrogen determination on milk which had been reconstituted and heated for 20 minutes on boiling water bath. Ammonia was determined by the method of Perkins (3) . Sodium borate was used by us in place of magnesium oxide because we had better recovery of added ammonia.