How does temperature of the milk affect the action of rennin? What is the optimum temperature? Why ...

Answer to #1

Heating the milk at temperatures from 72-95F provides an optimum environment for enzymes and bacterial activity. This contributes to the formation of the curd.

Answer to #2

Curd is cut to increase the surface area. The liquid that is observed when the curd is cut is whey.

Answer to #3

Rennet is the commercial form of rennin, which is an enzyme that coagulates milk by hydrolyzing casein.

Answer to #4

Velveeta cheese blended most quickly because it is more processed than the other cheeses and has emulsifiers. Cheddar cheese melted the slowest because it does not include an emulsifier.

Answer to #5

Processed cheese made by combining different varieties of cheddar cheese and emulsifying salts.

Answer to #6

Natural cheese is the curd or coagulated proteins (casein) of milk induced by enzymes or acid. Processed cheese is made from a single type of cheese or blends of different varieties with the presence of emulsifiers. Processed cheese includes pasteurized process cheese, cheese food, cold pack cheese food, and cheese spread. These products vary in moisture and the percentage of milk fat. They have a longer shelf life than natural cheese products.

Answer to #7

Heat denatures and coagulates proteins, which results in change of form and texture. Often, proteins toughen when exposed to heat. Heat causes browning of carbohydrates through the Maillard reaction. Some browning is desirable, but too much browning may occur with an excess of sugars, amino acids, or lactose in the cheese. Heat causes high-fat cheeses to melt. Higher-fat and higher-moisture cheeses have greater meltability. Ripened cheeses tend to melt and blend more easily when exposed to heat. One drawback of high-fat cheese when exposed to heat is the tendency to oil off by allowing free fat to be released and glisten on the surface of the product.

Answer to #8

Cheese food must be at least 51 natural cheese by weight, which is the same as cheese spread but less than processed cheese; cheese food also has higher moisture and lower fat content. An example is Velveeta cheese. Cheese spread has even more liquid, an emulsifier, and less milk fat. It is also softer and more spreadable than cheese food or processed cheese. Processed cheese is made from combining a variety of natural cheeses and includes an emulsifier; the moisture content must not exceed 40. The fat content is similar to that of the natural cheese from which it was derived.

Answer to #9

Rennin is an enzyme obtained from the stomach of milk-fed calves. Rennin coagulates milk by hydrolyzing casein. It produces a tough, rubbery curd with low moisture content.

Excellent answers

Thank you