3.3.2.2 Carbohydrates GapFill

Food preparation and cooking involves many techniques and methods which differently affect the structure of the food and the chemicals it’s made of. Various times of cooking, temperature and the presence of moisture or its lack will cause visibly different effects on carbohydrate-rich food products.

 StarchEggFlourSingle particles do not dissolve in water. Instead, they absorb it and swell, turning the mixture into a gel. This process happens when the mixture of  wateroiljuicesyrup and starch is heated and is called  digestiongelatinisationgastronomygelation. It is very useful in cooking since it helps thicken sauces and other mixtures, such as  parmesanyoghurtcustard saucejelly. The mixture has to be stirred constantly to prevent it from burning or becoming lumpy. In cold water, starch granules will first form a suspension, and then will fall to the bottom of the vessel.

Shorter chains of polysaccharides are also called  fedexdextrinspandexdeuters. When polysaccharides, such as starch, are cooked in  alkalinedrygreenwet conditions, their long chains break down into shorter ones – this is called dextrinisation. Dextrinisation occurs while baking bread (and other starchy foods) and is responsible for the sweetish taste, brown colour and crispiness of the crust. While making roux for a sauce, flour dextrinises. Different stages of dextrinisation lead to a final variation of colour and taste, and allow to obtain three main types of sauce: white, blonde and brown.

Sugars include molecules of monosaccharides and disaccharides. At high temperatures, sugar crystals break and melt into  syrupicegeljuice and change colour from light yellow through golden to brown. This is because oxygen and hydrogen are being evaporated and only black molecules of carbon are being left. Depending on the temperature and time of cooking, all foods containing sugars will caramelise. White sugar begins to caramelise at  250110160100 °C, and at 200 °C sugar burns.

 DextrinisationEmulsificationCaramelisationAeration is used in cooking to either change the flavour or affect the colour of the food to make it more appealing. This process is used when making fudge or burning the surface of crème brûlée to create the golden crunchy top. Caramel is also used in manufacturing cola-like beverages and is responsible for their dark brown colour.