The Versatility of Proteins: Functions and Properties of Protein

University:
College
Course:
College Biology
Academic year:

2022
Views:

29

Pages:

2
Author:

anon

Proteins Proteins are made of small units called amino acids that are linked together. When the protein is heated, the links change, causing the structure of the food to alter. On example would be the solidifying of egg white as it is exposed to heat. Functions and properties of protein Cheese Milk Yogurt Used to add texture and flavor to savory fillings and sauces (e.g béchamel sauce) Used as a binding ingredient Thickening agent (e.g dips and salad dressings) Melts when heated and provides a different texture (e.g on pizza) Gives flavor, color and constancy to products (e.g muffins) Adds a sharp acidic flavor Adds creaminess to products (e.g curry) The use of eggs: ❖ Aeration: The whole egg is able to trap large amounts of air when whipped – this is called aeration. ➢ When whisked, the protein stretches and uses air to create a mousse. When egg whites are whisked, they can hold up to seven times of their original volume. ➢ When exposed to heat, this mousse becomes stable and partially sets it. But when left to stand, it may begin to collapse. ❖ Coagulation: when eggs are heated, it solidifies and sets. ➢ Egg whites begin to coagulate at 60°c, but egg yolks only set at 65°c. ➢ Full coagulation occurs at 70°c ❖ Emulsification: when oil and water are forced to mix (e.g salad dressing) they form an emulsion ➢ Unless an emulsifier is added to the mixture, it will begin to split and go back to its original separate liquids. ➢ Egg yolk contains lecithin, which is also an emulsifier. This is why egg yolks are added to mayonnaise to stop it from splitting. ➢ Lecithin is also found in soya beans and used as a emulsifier in food production. Functions of eggs: ❖ Thicken: the protein coagulates when heated (e.g custard) ❖ Bind: dry ingredients together (e.g cake) ❖ Emulsifying: stops oil and water from seperating (e.g mayonaise) ❖ Enrobing: the egg acts as glue to bind a dry ingredient to a surface (e.g breadcrumbs and fish) ❖ Enrich: a sauce by adding color ❖ Setting: to hold a structure firm