Carbohydrates

Gelatinisation

Gelatinisation - Thickening of flour with water.

60C - Needed for gelatinisation to begin

80C - Most of gelatinision has happened

100C - Boiling point, gelatinisation finished

How gelatinisation happens - Amylose and amylopectin in starch. Granules break open and release amylose which forms a gel when heated

Affect of liquid on gelatinisation - More liquid, runnier sauce. Less liquid thicker sauce

Affect of type of starch on gelatinisation - Cornflour is best as it is 100% starch, plain flour is good as around 75% starch

Affect of temperature on gelatinisation - Needs hot and moist or thickening will not happen. Needs stirring and cooking for 2 mins. Starts at 60C and stops at boiling point

Affect of stirring on gelatinisation - Smooth sauce, prevemts starch form sinking and sticking which causes lumpy texture

Affect of sugar on gelatinisation - Causes auce to be come runny as it stops gel from forming

Affects of acid on gelatinsation - SHould be added to sauce at end as it can stop sauce form thickening

Dextrinisation

Dextrinistation - Dry heat turning starch (dextrin) brown, in baking, grilling, toasting

Dextrin flavour - Sweet and nutty taste to baked goods (croissants, toast, bread)

Caramelisation

Caramelisation - Heat applied to sugar to alter colour and flavour, in dry heating shallow frying and roasting

Process of caramelisation - Sugar heated and melts, water evaporates, 180C sugar turns to dark amber, colour and flavour develop

Products that use caramelisation - Biscuits, bread, pastries, meat, vegetables and fruit.