functional ingredients - full Flashcards
what is coagulation in eggs?
- when the eggs are heated they change from a liquid to a solid state.
- this usually occurs between 63 and 70 degrees.
- egg whites = 60 degrees egg yolks = 65 degrees full coagulation = 70 degrees
- when heat is applied, the proteins in the egg start to thicken.
- this is shown in products like: boiled eggs, omelettes, custard, cakes
what is coagulation in binding and glazing? (eggs)
binding - egg is added to hold together the ingredients by coagulation when heated.
examples: minced beef with breadcrumbs, biscuits
glazing - beaten egg is brushed over the top of baked foods. When it is heated the egg coagulates, giving the top of the food colour.
examples: sausage rolls, scones
what is aeration in eggs?
- aeration is the process of adding very tiny pockets of air to something.
- this makes mixtures light and fluffy and helps it rise
examples: swiss roll, meringue, cakes
what is emulsion in eggs?
- egg yolk contains an emulsifier called lecithin
- an emulsifier allows two ingredients (oil and water) to mix together and stops them from separating.
- examples:
mayonnaise - an emulsion of oil and vinegar
sponge cakes - margarine and egg yolk form an emulsion and it stops it from curdling and separating
low fat spreads (flora margarine)
what is shortening in fats?
- the process of shortening gives the food product a crumbly short texture.
- fat is rubbed round flour to produce a waterproof barrier, preventing water from being absorbed by the flour.
- this stops the dough from being elastic and gives a short crumbly texture.
- examples: shortcrust pastry, shortbread, biscuits
what is aeration in fats?
creaming - fat (margarine) and sugar are beaten together with a wooden spoon or electric whisk.
- this causes tiny bubbles to get trapped in the mixture.
- this makes the mixture lighter and helps the cake rise
rubbing in - fat is rubbed into flour using your hands, the fat coats the flour until it looks like breadcrumbs.
- air is trapped in the mixture as a waterproof barrier is made with fat round the flour
- e.g. scones, pastry, rock buns
what is glazing in fats?
- when butter is melted and can be poured over cooked vegetables to give a shiny, glazed finish. (carrots, potatoes)
- when making a white sauce, butter can be added to give the sauce a shine. without fat the sauce will look dull.
- e.g cauliflower cheese, macaroni cheese, lasagne
what is crystallisation in sugar?
- when sugar is dissolved then cooled, and the end result is the sugar beacoming hard/solid. (usually dissolved through heat)
- when the sugar and water are boiled the water is burnt off, the liquid will thicken making syrup.
- small crystals will form on cooling.
- dont stir the liquid when sugar is dissolving as large crystals will form, leaving a gritty texture in the product.
- e.g. sweet making, jam making (boiled sweets, fudge, tablet)
what is caramelisation in sugar?
- when sugar is melted by heat, it will turn brown. (oven, grill, blowtorch)
- the different colour stages can indicate taste changes.
- light in colour = very sweet darker in colour = more rich, nutty or bitter
- if you heat the sugar for too long it becomes black in colour and chars which gives it a bitter flavour.
- examples:
sugar can be added on top of food then heated (creme brule)
cakes and baked items - used to colour the top of products
sweets - toffee and tablet
what is aeration in sugar?
- the sugar traps air when creamed with fat, making the product lighter in texture.
- sugar helps bread to rise by helping the yeast to produce carbon dioxide.
- sugar is also added to products for the sweetness.
- e.g cakes, breads, desserts, biscuits
what is gelatinisation in flour?
- occurs when starch (flour) and liquid are heated which will thicken a sauce.
- as the liquid is heated, starch molecules absorb the liquid and thicken it by swelling to 5 times their size.
- a lumpy sauce can be caused by not constantly stirring the liquid.
- a thin sauce sauce means it hasnt been heated long enough or not enough starch has been used.
what is dextrinisation in flour?
- dry heat (toaster, grill or oven) on starch will cause it to change to dextrin.
- this causes the surface of the food to turn golden brown
- e.g. burger buns, toast, scones
- if the starch is overcooked it will char and burn
what is fermentation in flour?
- when yeast produces carbon dioxide and alcohol under the right conditions. (time, warmth, moisture and food)
- flour contains alot of gluten (protein) which gives stretchy elastic dough that can trap the carbon dioxide gas.
- the flour is the food for the yeast that is needed in bread making.
- when the dough is cooked, steam is produced from the liquid.
- the gluten is stretched by the bubbles of carbon dioxide gas produced which causes the bread to rise.
what is coagulation in flour?
- flour contains gluten which sets giving the sponge/bread its springy firm texture.
- its the firming or hardening of the gluten proteins in flour to give a firm structure.
- this is usually caused by heat.
what is binding in liquids?
liquids are used to bind dry ingredients together.
