Beef Stir-fry
DENATURATION, GELATINISATION & COAGULATION:
INGREDIENTS: (BETWEEN 2)
METHOD:
*Remember to place the cooked meat and vegetables into a clean bowl to avoid cross-contamination. Cross-contamination is allowing a contaminated substance into contact with something clean. (In this circumstance, raw meat) _ DEFINITION OF DENATURATION & COAGULATION: Denaturation is the permanent alteration of the protein structure, made of amino acids. Amino acids are the building blocks of protein, and are joined together by chemical bonds that hold them in a helical structure. The alterations may be caused by acids, or physical agitations that break the chemical bonds. Coagulation cannot occur without denaturation. Coagulation is defined as the transformation of proteins from a liquid state to a solid form. Once proteins are coagulated, they cannot be returned to their liquid state. (eg. raw to cooked eggs) Instances when the two reactions occur are during the slicing, marinating and cooking of the meat. Denaturation gives the meat flavor, texture and edibility; whilst coagulation ensures that the meat isn’t raw as to not pass on food contamination/poisoning. Physical changes include the texture, colour and flavour, the meat changes from red to brown to show that it has been cooked, and the texture would be firmer- giving the food some slighter physical structure. |
EQUIPMENT:
Gelatinisation as a chemical process takes place in this recipe as does another important series of chemical changes. Without these reactions, the food- particularly the meat and vegetables- would be unpalatable and harder to chew, and digest. The sauce within the recipe uses a flour that contain a different type of starch that produces a translucent sauce once it gelatinises. The meat also goes through significant changes as it cooks, and the protein molecules are exposed to heat. These two chemical changes -denaturation and coagulation- only occur in protein foods. When protein foods are exposed to certain conditions (one being heat protein molecules) permanently alter in structure (denaturation). Further heating sets the protein, and often there are accompanying colour changes which can be seen when red meat turns from red; to brown. Once both protein and vegetables are both safely cooked, using the same pan is okay. Cross-contamination is not possible for all substances have been thoroughly cooked. Examples of other foods that include the two chemical reaction are:
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Tips & Evaluation
It is extremely important that all the reactions occur, as each offers stability and edibility to ensure that it will not affect health or taste. Gelatinisation provides the dish with a sauce from the meat juices, adding flavour and colour to the rice vermicelli. Denaturation & coagulation work together to ensure texture and edibility are correct.
The beef is to be properly prepared to avoid food poisoning, make sure it has had the proper amount of time to cook. If uncertain, check if the meat is raw by cutting it open. Avoid cross-contamination by using clean bowls every time the meat is moved. Wash all plates directly after use as to not confuse which one hasn't been used. Wash hands after marinating and cutting the beef before handling any other food.
The beef is to be properly prepared to avoid food poisoning, make sure it has had the proper amount of time to cook. If uncertain, check if the meat is raw by cutting it open. Avoid cross-contamination by using clean bowls every time the meat is moved. Wash all plates directly after use as to not confuse which one hasn't been used. Wash hands after marinating and cutting the beef before handling any other food.