fnt revision Flashcards
what are micronutrients
these nutrients are vital for health but only needed in micro quantities (vitamins, minerals)
what are macronutrients
needed by our bodies in much larger quantities (carbs, proteins, fats)
what is function of protein?
builds new cells (e.g muscle and hair), repairs body tissues, and supplies heat and energy if necessary.
what is the function of carbohydrates?
provides heat and energy, provides fiber for a healthy digestive tract. (healthy bowel, prevents constipation)
what is the function of fat?
provides richest source of heat and energy, satisfies hunger, provides padding around heart and kidneys, carrier for vitamins A D E K.
Function of vitamins?
regulates body processes to keep body functioning correctly, protect body for diseases (e.g scurvy)
where are vitamins found?
fruit, vegetable, grains
function of minerals?
regulates body functions, builds selected body tissue (iron for blood, calcium for teeth.)
example of minerals?
milk, meat, fish, cheese, fruit, veg
water function?
regulates body temp, gets rid of waste via the kidneys, carries nutrients in blood. found in milk, fruit, veg, water
functional properties defenition?
Physcial and chemical changes of food that occur during storage, preperation and cooking. these properties affect the carbohydrates, proteins, fats found in food.
dextrinisation?
the browning of carbohydrates (starch) when subjected to dry heat. e.g toast, cakes, biscuits
crystallization?
when sugar crystals form in a supersaturated solution. e.g toffee, brittle
caramelization
carbohydrates (sugars) turn brown in the presence of heat. (toffee, baking cakes and biscuits.)
gelatinisation
when flour (starch) is blended with liquid and heated. the starch granules swell and burst, thickening the liquid. e.g roux, custard
what factors affect gelatinisation?
temperature- must be done over heat
agitation- stirring prevents lumps from forming
other ingredients- acid (gives less volume), sugar (competes with starch for water, thus reducing the amount of water available for gelatinization.)
denaturation
when a protein structure unravels and changes from its natural state.
what is denaturation- caused by?
agitation- whisking egg whites
acidity- making sour cream and yoghurt.
enzymes- marinating meat
salt- cooking eggs with salted water
coagulation
occurs after denaturation. when a protein changes from a liquid state to a solid state. e.g cooking eggs, making meringue, baking cake
aeration
process of incorporating air into food products to make them lighter and/or more volume e.g creaming butter and sugar, meringue, cream
factors affecting degree of mechanical aeration?
-the product being beaten
-length of beating time
-severity of beating
-use of additives (e.g sugar, gelatine)
-temperature of product
-presence of fat (when whipping egg whites)
what are the factors that affect egg white foam?
fat- even the smallest amount of yolk will block the formation of foam
acid- e.g cream of tartar, lemon: decreases ph and improves stability of foam.
temp- reaches greater volume more quickly at room temp than cold temp
sugar- creates stable foam that will not collapse quickly
what is Mailliard reaction?
a chemical reaction between amino acids and sugars that gives browned food its distinctive aroma and flavor. e.g bread, steak
what is emulsification
mixture of two immiscible liquids like oil and water to form stable mix. With addition of emulsifier the two immisible liquid emulsify (combine). e.g mayo, icecream
