There are three main differences between the two:
I. Shape
The shapes of natural cheese are very rich, and the common shapes are block, slice, cube and shredded. In order as shown in the figure.
There are also cylindrical, fan-shaped and so on.
The shape of processed cheese is relatively much less, usually sliced, put in metal cans, cartons, plastic bottles or pipes, and can be squeezed out like salad dressing:
From the shape point of view, processed cheese and natural cheese have slice shapes, which is difficult to distinguish. Processed cheese is generally soft and has a low melting point, while natural cheese, if it can be cut with a knife (usually cut from block cheese with a knife), has a hard texture, and it may still be distinguishable by looking and touching it.
Second, the composition
Natural cheese: The raw material for making natural cheese is cow or sheep milk. By adding acid or chymosin, protein in milk is condensed into small pieces and precipitated, which are layered with whey. Then the excess water is squeezed out to form a larger cheese block. Finally, salt, pigment and microorganism are added, which gives cheese a special flavor, texture and color through fermentation, and then gives it a special shape through mechanical processing.
Main ingredients: water: 30. 17%, fat: 34.39%, protein: 3 1.23%, minerals: 4.3 1%.
Through these data, we only need to know two things:
1, the composition of different kinds of cheese will change, but protein and fat are always the most important ingredients.
2. Cheese has oil and water (the ratio is close to 1: 1), and oil and water are incompatible, so it needs to be fully emulsified, so that the cheese will not be layered when it is placed.
Protein in cheese is a natural macromolecular emulsifier, which makes cheese a colloid with uniform emulsification. However, under the condition of heating, natural cheese is still easy to produce oil.
Processed cheese: According to FDA regulations, at least 5 1% of processed cheese is natural cheese, and less than 49% of the remaining ingredients include additives, water and other milk raw materials, such as dry milk, anhydrous milkfat and whey solids. The additive content of processed cheese is indeed higher than that of natural cheese, and it is purposeful to add additional additives.
PS. The original answer is "5 1% of the raw materials for processed cheese are natural cheese and 49% are additives". This description is incorrect. Thanks to @ Liang Hai for pointing out the mistake, the author corrected it on August 30th, 20 13.
Objective 1: To improve functionality.
How to make processed cheese? First, take a small pot, put the chopped natural cheese pieces into it, and heat it until it melts. At the same time, add some emulsifying salts (such as sodium phosphate and sodium citrate), antibacterial preservatives, and some seasonings (such as jalapeno, a Mexican pepper) and fully stir them to form a homogeneous and stable oil-in-water emulsion system.
Through this process, some properties of cheese have been improved:
(1) Emulsifiability becomes better. When cheese is heated and melted, water and oil will not separate. For example, when a hamburger is heated, the thin piece of cheese melts, but the texture and taste will not change.
(2) The shelf life is prolonged. Quality assurance includes two aspects. First, by adding preservatives, mold and deterioration are inhibited, and the edible time of cheese is prolonged. Secondly, by adding emulsified salt, cheese will not lose its original shape because of melting when it is sold in warm areas, thus prolonging the time for cheese to maintain high quality.
(3) The flavor is enriched. Because of the seasoning and the natural cheese used to make processed cheese, it can be a mixture of many different flavors of cheese.
(4) It is endowed with extensibility and spreadability. If it is made into cheese sauce for dipping bread (such as pretzel), this process can give cheese sauce a silky texture and make it not easy to agglomerate.
Objective 2. To solve the leftover of natural cheese. Natural cheese will eventually be cut into beautiful shapes for sale, and there are always irregular edges and corners left, or some natural cheese can't be sold and accumulated in the warehouse, so use it to make processed cheese ~
III. Shelf life and storage method
Natural cheese needs refrigeration. Fresh cheese (the name of a kind of cheese refers to Fresh Mozzarella, Ricotta, Cottage), a few days to two weeks; Soft cheese, 1 week; Semi-soft cheese, 2~3 weeks; Hard cheese: 5 weeks; Very hard cheese: 10 week. Processed cheese belongs to soft or semi-soft cheese, which can be stored for 3~4 weeks and does not have to be refrigerated.
How to judge processed cheese?
After having a basic concept of two kinds of cheese, there are other ways to judge besides the instructions on the package:
1, a lot of sliced cheese in the sandwich burger is processed cheese. For example, American cheese American cheese (this is the variety name, not the place of origin).
2, you can dip in biscuits, and the cheese sauce with good fluidity is processed cheese.
3. Cheese that does not require refrigeration is processed cheese.
4, natural cheese is expensive, and remanufactured cheese is cheaper.
About how to choose cheese:
1, according to taste: undoubtedly the most important factor. I don't know until I eat it.
2, according to nutrition: the nutrition of cheese mainly comes from high protein. Processed cheese has a low proportion of natural cheese, contains a lot of additives and contains more salt. The nutritional value is naturally inferior to that of natural cheese. What's the difference in nutrition between different kinds of natural cheese? It depends on the content of protein and fat, and high protein, low fat, less salt and low sodium are ideal. At this time, you can just look at the nutrition label on the cheese, or refer to this webpage:
Nutritional Information Comparison for Dairy
3, according to the use: For China people, there are basically three uses: (1) sandwiched in hamburgers; (2) used for baking and cooking, such as making cheese biscuits, cheesecake, pizza and cheese baked rice; (3) eaten directly as snacks. The first one has a wide choice of cheese varieties, such as sliced processed cheese, Cheddar, Swiss, Monterey Jack, Colby and so on in natural cheese, as long as the original shape of cheese can be basically preserved after melting. The second type is mozzarella, mascarpone, cheddar, ricotta and so on. The third use requires the highest quality of cheese. It's best to buy block cheese, cut or slice it yourself and taste it slowly. It can be accompanied with red wine.
Common cheeses with high acceptance in China:
1, Swiss cheese and baby Swiss. A common cheese with holes in cats and mice is called Swiss cheese. The pores come from carbon dioxide produced during microbial fermentation.
2, the car hits the cheese Chedar Cheese. Mild and medium levels are easy to accept, and sharp and extra sharp should not be tried easily.
3. Maslira Mozzarella. More common in pizza and baked rice.
4. Parmesan Parmesan. Parmesan in China is mostly powdered (cheese powder), which is sprinkled on pizza and baked rice to increase flavor.
5, fresh cheese, such as Cottage, Ricotta, Fresh Mozzarella, the first two are eaten directly, mixed with salad, and the last one is rolled with sliced tomatoes.
6, Cream cheese cream cheese, mostly used to make cheesecake.
Don't try the cheese easily:
1, cheese fermented by mold, the taste is generally very strong, and it is not acceptable for the first time. （。 . . . Some people, such as me, still find it hard to accept cheese for a long time ...) Representative: blue cheese.
2. Sharp and extra sharp cheese refer to cheese whose fermentation period exceeds 12 months or even 3-5 years. Old, too strong! Although some people like it. . .