July 22/Beijing, China/Technology Business Journal -- According to recent research from Beijing, China, "Soft cheeses were manufactured from bovine milk with the addition of 0-12% sesame protein isolate (SPI), to investigate rheology, texture and microstructure at different stages of cheese making. SPI addition reduced the speed of milk fermentation, kappa-casein proteolysis of rennet and elongated the time of cheese curd formation."

"Renneted milk storage modulus G'(60min) was decreased, and coagulation time increased with increasing SPI content. Low SPI supplements (4% and 8%) enhanced the hardness, cohesiveness, adhesiveness and gumminess of the soft cheese, while high SPI addition (12%) deteriorated the texture. In the cheese curd gel matrix, SPI distributed as specific SPI-gel clusters on the surface of curd fractures, stacked or fused with ball-shaped casein micelles and wrapped up to casein gel strands," wrote X.M. Lu and colleagues, China Agricultural University.

The researchers concluded, "In summary, SPI actively interacted with casein colloid throughout the cheese making process."

Lu and colleagues published their study in International Journal of Food Science and Technology ("Effect of Sesame Protein Isolate in Partial Replacement of Milk Protein on the Rheological, Textural and Microstructural Characteristics of Fresh Cheese." International Journal of Food Science and Technology, 2010;45(7):1368-1377).

For additional information, contact S.W. Chen, China Agricultural University, College Food Science & Nutrition Engineering, Chinese Minist Education & Municipal Govt Beijing, Key Laboratory Functioning Dairy Science, Beijing 100083, China.

From the August 2, 2010, Prepared Foods E-dition