A Method for Standardizing the Biacetyl Content of Creamed Cottage Cheese

Abstract

Biacetyl and volatile acids contribute considerable flavor to creamed cottage cheese. A method is outlined for the development of these compounds in skim milk, and such skim milk is used in the preparation of a creaming mixture for cottage cheese. The creaming mixture is prepared as follows: Skim milk is heated to 190[degree]F and held for 1 hour, or it can be heated in an autoclave at 250[degree]F for 10 minutes. After cooling to 70[degree]F it is inoculated with 2 to 4% of a culture of Streptococcus citrovorus and incubated at 70[degree]F for about 24 hours. Sterile citric acid solution (15%) is added to lower the pH to 4.3, and the material is further incubated at 70[degree]F for 20 to 24 hours. Considerable biacetyl and volatile acids are formed during the latter incubation. The skim milk thus prepared is used to adjust the fat content of cream to about 12%. Standardization of biacetyl is accomplished by varying the fat content of cream used in the creaming mixture and therefore the amount of skim milk culture to standardize the fat content. Cheese creamed with such a preparation has an appreciable amount of flavor immediately after creaming.