Natural cheese is generally made by adding a microorganism to milk which is capable of metabolizing lactose to produce lactic acid and develop acidity. The milk is usually set with a milk clotting enzyme, such as rennet, or by developing acidity to the isoelectric point of the protein. The set milk is cut, whey separates and is recovered from the resulting curd. The curd may be pressed to provide a cheese block and curing takes place over a period of time under controlled conditions. A product having flavor and body characteristics of natural cheese has been made by replacing at least a portion of the animal fat of the milk with vegetable fat and/or by replacing at least a portion of the casein of the milk with a vegetable protein. Such cheeses are referred to as "analog cheese".
Processed cheese is made from one or more varieties of natural cheese, such as cheddar cheese, colby cheese, swiss cheese, washed curd, granular curd cheese, brick cheese and muenster cheese. Processed cheese is made by grinding the natural cheese, combining the particulate cheese with an emulsifying salt and heating it to a temperature sufficient to pasteurize and fluidize the cheese.
There are three general types of processed cheese. These include pasteurized processed cheese, pasteurized processed cheese food and pasteurized processed cheese spread. These processed cheese have certain characteristics which are desirable to cheese consumers. They all have a smooth, creamy texture and a slight firmness which is attributable to the presence of at least 20% fat in the processed cheese formulation.
In the United States, Standards of Identity established by the Food and Drug Administration (FDA) apply to processed cheese. Based on the Standards of Identity, the main differences between the types of processed cheese is their moisture and fat content and the use of optional components.
Processed cheese has a moisture content of not more than 40% and a fat content of not less than 47%. Optional ingredients for pasteurized processed cheese includes an edible acid, cream, water, salt and spices.
Pasteurized processed cheese food generally may include the optional ingredients of pasteurized processed cheese plus other optional ingredients which may include additional dairy ingredients, such as milk, skim milk, whey, buttermilk, skim milk cheese and albumen. It has a much lower fat content. Pasteurized processed cheese food may have a fat content as low as 23%. The moisture content is not more than 44%.
Pasteurized processed cheese spread may include the optional ingredients of pasteurized processed cheese food and may also include a gum. The fat content of pasteurized processed cheese spread may be as low as 20% and it has a moisture content in a range between 44% and 60%.
Processed cheese is made by grinding or mixing while heating one or more cheeses of the same two or more varieties. Processed cheese is heated for no less than thirty seconds at no less than 150.degree. F. These cheeses are made in mass quantities. They are cooked by use of a horizontal cooker, sometimes called a laydown cooker, which can hold up to 500 pounds or more of cheese. Often, the processed cheese is then automatically packaged in air tight cartons.
In recent years, there has been a substantial amount of research effort directed to reducing the amount of fat, particularly saturated fats, in foods. In particular, there is great interest in reducing the level of fat in cheese products, such as processed cheese. It would be highly desirable to develop a processed cheese product with very low levels of fat, but which retains the body, texture, organoleptic properties and meltability of a pasteurized processed cheese food containing at least 23% dairy fat.
To date, most related efforts have been directed to the use of starch and starch gum combinations to replace the caseinate fraction in cheese and other food products.
U.S. Pat. No. 4,552,774 is directed to a cheese-like product containing up to 10% by weight starch which prevents separation during melting.
U.S. Pat. No. 4,499,116 describes imitation cheese products having up to 80% by weight of the caseinate replaced by modified starches containing 15% to 40% by weight amylose. U.S. Pat. No. 4,608,265 and U.S. Pat. No. 4,695,475 describe imitation cheese products having up to 100% replacement of caseinate by modified starches having an amylose content of at least 40%. U.S. Pat. No. 4,937,091 describes an imitation cheese product where up to 100% of the caseinate fraction may be replaced by partially enzymatically debranched starch (amylopectin), a short chain amylose and amylopectin having the texture, thermoreversibility and emulsification characteristics of caseinates found in imitation cheeses.
U.S. Pat. No. 4,847,107 describes a method of preparing fresh cheese in a finely particulate form where the particles are prevented from sticking together by the addition of starch to milled cheese.
U.S. Pat. No. 4,568,555 is directed to a cheese sauce containing various gums to provide shelf stability without the need for refrigeration.
Other patents include U.S. Pat. No. 3,806,606 which describes a synthetic cheese product containing essentially narrow melting range fats, wheat gluten, egg white and gelatin to provide a cheese with the same texture and eating quality of natural cheese.
None of the above-cited patents disclose a processed cheese product having very low fat levels which retains the body, texture, organoleptic properties and meltability of a pasteurized processed cheese food containing at least 23% fat made in accordance with the Standards of Identity of the United States FDA.
Accordingly, it is an object of the present invention to provide a low fat cheese product containing substantially no fat which has the body, texture, firmness, organoleptic properties and melting qualities of processed cheese containing at least 23% dairy fat. It is a further object of the present invention to provide a method for preparing such low fat cheese products. These and other objects of the present invention will become apparent from the following detailed description.