Influence of various coagulation factors on chemical composition of sera gained by centrifugation from casein gel

Technological operations applied during curd processing influence syneresis and total solids content of cheese. Syneresis is not a simple physical process representing whey segregation due to curd contractions. Numerous factors can influence the process of syneresis. The aim of this work was to investigate the influence of various parameters (pH, quantity of CaCl2 added, temperature of coagulation and heat treatment) on induced syneresis. Reconstituted instant skim milk (control samples) and reconstituted instant skim milk heated at 87oC for 10 min (experimental samples) were coagulated at 30oC and 35oC, and pH of 5.8 and 6.2 with 100, 200 and 400 mg/l of CaCl2 added. According to our results, these parameters had significant influence on nitrogen content of serum as well as on the distribution of nitrogen matter from gel into sera. Due to the formation of coaggregates the best rheological properties of gel were obtained for experimental samples coagulated with 400 mg/l of CaCl2 added at pH 5.8 and temperature of 35oC.