Meat+Tenderizing+Enzymes+(Janet+Xiao)

Introduction
Image Source: http://www.epicurious.com/images/cooking/menus/cooknow/steak.jpg

Have you ever tried cooking steak at home? Perhaps you intend for it to be tender and juicy -- just like the ones at (good) restaurants -- but the meat turns out tough and unpalatable, and you end up having to order pizza instead. Are you missing an ingredient? Perhaps using meat tenderizers **papain** or **bromelain** will help.

How Do They Work?
Papain and bromelain are both proteolytic enzymes, or proteates -- that is, enzymes with the ability to break down proteins. As explained on this page (in the "What Are Enzymes?" section), enzymes catalyze, or quicken the pace of biological chemical reactions. One such reaction is that of [|hydrolysis], or the breaking down of substances by adding water. For example, papain hydrolizes proteins to form oligopeptides and amino acids.

Papain and bromelain can be applied to meat in various ways. Previously, an antemortem process was used, in which the enzyme was injected into live animals. However, this was considered inhumane and largely put out of use. Modern methods include mechanically allowing the enzymes to penetrate the meat through a process called "forking," or simply letting the enzyme come into contact with the meat prior to cooking.

The Gathering Process

 * **===PAPAIN===** || **===BROMELAIN===** ||
 * In order to obtain latex from papaya fruit, the neck of a papaya is scored, and latex dries on the fruit or is dripped into a container
 * The latex is further dried, until it is classified as a "dried, crude material"
 * The material is purified in order to remove contaminating substances
 * The papain is extracted during the purification process, and supplied in powder or liquid form [[image:http://images.allrecipes.com/site/allrecipes/area/advice/gloss/150/PDC196HL.gif align="center"]] http://images.allrecipes.com/site/allrecipes/area/ advice/gloss/150/PDC196HL.gif ||
 * The stump root of a pineapple is collected, peeled and crushed to extract the juice, which contains the soluble enzyme
 * The enzyme is precipitated, for purification purposes
 * It is produced as a powder [[image:http://www.rachelleb.com/images/2004_06_20/papaya.jpg width="300" height="187" align="center"]] http://www.rachelleb.com/images/2004_06_20/papaya.jpg ||
 * It is produced as a powder [[image:http://www.rachelleb.com/images/2004_06_20/papaya.jpg width="300" height="187" align="center"]] http://www.rachelleb.com/images/2004_06_20/papaya.jpg ||

Properties of Papain
Papain is active over a wide pH range, making it easier to utilize. Papain has the most stable temperature out of all the enzymes currently used to tenderize meat because of its low temperature of deactivation. (170 to 185 degrees Fahrenheit). However, this also means that cooking meat at a "medium rare" level will not inactivate papain, thus, if the meat is subsequently put into storage for a long period of time, the papain will continue to digest it until it becomes mushy and cannot be eaten.

Properties of Bromelain
Bromelain shares many properties with papain - for example, the pH range it remains active in is similar. It has a lower temperature of inactivation (160 deegrees Fahrenheit), however is still not low enough for the inactivation of meat cooked medium rare.

How To Obtain and Use Meat Tenderizing Enzymes
Image Source: http://www.vitalita.cz/images/prod_b/super_bromelain_papain.jpg

90% of meat tenderizers are used in consumer households. Papein and bromelain are processed into powders or liquids, packaged, and are sold in grocery stores and supermarkets. The enzymes can be sprinkled on uncooked meat or mixed into marinade, giving the enzymes plenty of time and area of interaction to break down the meat.

Alternative enzymes
Other enzymes that may be used for meat tenderizing include ficin (collected from fig trees), pancreatin (from pancreas glands), and ones found in //Bacillus subtilis// and //Aspergillus oryzae//. However, papein and bromelain are by far the most widely used.

Sources Used
[|] [|http://www.enzymedevelopment.com/html/applications/protein.html] [|http://www.vitamins-supplements.org/digestive-enzymes/papain.php] http://www.vitamins-supplements.org/digestive-enzymes/bromelain.php http://en.wikipedia.org/wiki/Papain [|http://en.wikipedia.org/wiki/Bromelain]