Manufacture of culture-based acid curd using micellar casein concentrate

Document Type


Publication Date



American Dairy Science Association


Journal of Dairy Science




Suppl. 1






micellar casein concentrate, acid curd, imitation mozzarella cheese


Micellar casein concentrate (MCC) is a high protein ingredient produced by microfiltration of skim milk. It has an elevated level of casein as a percentage of total protein as compared with skim milk. Acid curd is a protein concentrate, which is produced by precipitating the casein at the isoelectric point (pH = 4.6) using starter cultures or acids without rennet. Acid curd is typically manufactured from skim milk in a process similar J. Dairy Sci. 103 (Suppl. 1) 131 to Cottage cheese manufacture. However, this results in the production of acid whey which is difficult to utilize. We theorize that acid curd could be produced from MCC instead of skim milk which could improve the efficiency of manufacture and allow for removal of the whey protein before acid curd manufacture. The objective of this study was to utilize MCC to manufacture of acid curd using starter cultures. The MCC (pH~6.6) was prepared and standardized by mixing milk permeate, water, and MCC powder to produce a solution with 13.0% solids, 9.0% protein, and 2.0% lactose. Thermophilic cultures were added (0.005%) to the MCC and incubated at 43°C. The fermentation time was approximately 15 h to decrease the pH to 4.6. After reaching pH 4.6, the curd was cut and mixed gently during heating to 50°C in 1 h. The whey was subsequently drained and the curd was washed with water and then pressed. After pressing, the curd was analyzed for solids, protein, lactose, lactic acid, ash, and mineral profile. The moisture adjusted yield efficiency was also calculated. This trial was repeated 4 times. The mean was 24.9%, 23.0%, 0.90%, and 97.4% for solids, protein, ash, and moisture adjusted yield efficiency, respectively. The whey had 0.58% lactose and 1.43% lactic acid. The calcium and phosphate content of the acid curd was 0.19% and 0.12%, respectively. No significant differences (P > 0.05) were detected in the composition of the acid curd made from the 4 replicates of the MCC. We conclude that MCC can be utilized in manufacture of acid curd with starter cultures. The culture-based acid curd will be utilized as an ingredient in imitation Mozzarella type cheese in subsequent studies.