The influence of heat treatment on the efficiency of milk nitrogen compounds recovery

Cilj ovih istraživanja bio je da se ustanovi utjecaj različitih režima termičke obrade na iskorištenje dušičnih tvari mlijeka. Rezultati istraživanja pokazali su da termička obrada na 95-97 °C omogućava znatno veće iskorištavanje dušičnih tvari mlijeka i da se ono kreću u prosijeku 94,7 %, što predstavlja povećanje od 10,82 %. Povećano iskorištenje dušičnih tvari posljedica je nastajanja koagregata bjelančevina mlijeka (kemijskog kompleksa između kazeina i nekih proteina mliječnog seruma) koji nastaju kao posljedica djelovanja korištene temperature od 95-97 °C u trajanju od 20 minuta.The aim of these investigations was to determine the influence of different thermal treatments of the efficiency of recovery (separation) of nitrogen compounds of milk in some, milk processing. This is done having in mind a lack of investigations in our country as well as the possibility of application in dairy technology. Skimmed milk was subjected to thermal treatment at 85 °C for 20 seconds and at 95-97 °C in the course of 20 minutes. The results obtained show clearly that the more severe heat treatment led to a much higher separation of nitrogen compounds at pH 4,6 and averaged 97,7 %. Compared with the recovery of nitrogen compounds from pasteurized milk under the same conditions, it was 10,82 % higher. The differences appear as the result of protein coagregates formation under the influence of the heat treatment at 95-97 °C for 20 minutes