Rennin+in+Cheese+Production+(by+Paul+Lee)

=RENNIN in Cheese Making=

__History of Cheese Making__
One of the first times that the cheese is ever mentioned in the written history is in the bible. In bible, it was said that ‘cheese obtained from animals’ has been devoted to King David of Israel. Furthermore, there are evidences that Ancient Greeks and Romans knew the existence of cheese and valued it just like Northern Europeans did. Sometimes, ways to make cheese were kept in secret, and ways to make certain types of cheese are still in secret. In the medieval ages, priests taught normal people how to make cheese. Since people needed special technology of condensing milk in to 1/10 of its original size to make cheese using enzyme called rennin, it was not very easy for medieval people to successfully make cheese.

Although there are many ways to make different types of cheese, but the general mechanism of making cheese is similar, and all types of cheese making process involves rennin. Rennin in cheese making has a significant role, which is to solidify milk. First, to make rennin to work, it is necessary to keep the temperature of the milk at 20 to 40 degree Celsius. Given that condition, rennin starts to react with casein(one type of protein exists in milk) to solidify the milk. When the rennin meets casein, according to the [|lock-and-key theory], casein sticks with rennin and rennin then breaks down casein into paracasein and that adds up with calcium to form calcium paracaseinate. Then calcium paracaseinate joins with water and milk fat, solidifying milk. Furthermore, it was known that one rennin can solidify 10 to 15,000 parts of milk. Besides of this, there are two types of rennin; one obtained from vegetable, and other one obtained from animals. Except for the products for vegetarians, generally, rennin obtained from newly-born calves is used for the cheese making.

__Why Rennin?__
Although cheesemakers can use many types of acids to solidify milk, they use rennin to obtain cheese from the milk. The main reason for this is because rennin is the most natural ingredient for making cheese. Rennin is obtained from the forth stomach of newly-born calves, and that makes rennin favored by cheesemakers because they don’t have to spend extra money for purchasing acids, and also because of that it was generally known by the cheesemakers that milk solidified by rennin makes relatively better cheese than the milk solidified by acids. Furthermore, research has found out that rennin has an effect of preventing low blood pressure of humans.

__Other Interesting Facts__

 * There are more than 400 types of cheese produced only in France.
 * Human beings started to raise milk-producing animals (sheep) in about 12,000 B.C.
 * Because of the black plague that swept the entire Europe, many ways to make different types of cheeses were lost.
 * Holes made in some kinds of cheese is made by bacteria producing CO2 (carbon dioxide)

__Images__
<-Various types of cheeses <- Cheese that finished processing <- Cheese is being processed. Works Cited


 * "Cheese." __Britannica Encyclopedia__. Ed. Sang Woo Jang. CD-GX ed. Seoul: Britannica Company, 2001. 1-7.
 * "Rennin." __Britannica Encyclopedia__. Ed. Sang Woo Jang. CD-GX ed. Seoul: Britannica Company, 2001. 1-2.
 * Ophardt, Charles. "Enzymes- Lock&Key." __Elnhurst College__. 2003. Elnhurst College. 18.Nov.2006 .
 * Vegetarian Society. "Information Sheet- Cheese & Rennet." __Vegetarian Society__. Unknown. Vegetarian Society. 17.Nov.2006 .