摘要：In this study the skim milk and whole milk samples were concentrated for 2-fold by ultrafiltration ( UF ). Then the skim milk retentates were recombined with cream as such and 2-times protein / fat ratio of whole milk retentate . The modification of the milk proteins and fat globules was explained as the variation of protein surface hydrophobicity , and UF performance was explained as a result of collected permeat volume in giving time intervals during the ultrafiltration . It was also studied on renneting properties of these samples and their retentates . It was found that the number of hydrophobic sites of the whole milk 's protein system lower than that of skim milk and it was observed at minimum in the whole milk 's retentate . It is suggested that the renneting process accelerated due to the modification of protein structure resulted by UF and protein/ fat ratio.
