guidelines for a healthy diet
1 base meals on starchy foods
2 eat lots of fruit and vegatables
3 eat more fish
4 cut down n sat fat and sugar
5 eat less salt no more than 6g a day
6 get active and try to be a healthy weight
7 drink plenty of water
8 don't skip breakfast
bulking agent - the starch forms the main structure of the product, e,g flour in biscuits or cakes
thickening agent -when the starch is heated in a liquid, the walls of the starch becomes soft and allows the liquid to pass slowly throught them. this makes the granules swell until they burst.
modified starches - this is a starch that has been altered (modified) to perform additonal functions to react to different processes. otherwise know as smart starches
modified starch is used to thicken food when boiled water is added i.e cup-a-soup
pre-gelatinised starch is used to thicken instant desserts without heat. A cold liquid can be added and the dessert will thicken when stirred or whisked ie instant whip.
Gelling agent - after full gelatinisation has occurred the thickened liquid forms a gel. On cooling the ge then soildifies and is no longer in a liquid state.
Starch particles do not dissolve in liquid. Instead they form something called a suspension.
if the liquid is not stirred, the starch granules sink to the bottom, stick together and start to form lumps.
when heated at 60oc the starch granules begin to aborb the liquid and swell.
at 80oc the partilcles will have absorbed about 5x thier volume of water until they burst open and then release starch, thickening the liquid
the gelatinisation is compelte when the liquid reaches boiling point
functions of sugar
sweetnes : used to sweeten drinks and food i.e tea
flavours : improves or changes the flavour by removing the sour taste e.g tomato products
fermentation : sugar can speed up the process of fermentation when yeast realses carbon dioxide
adds colour : when the sugaar is heated it turns golden brown in the process of caramelisaation
stabilises ; it can stabilise whisked mixtures i.e meringue
extends shelf life : it helps to keep the products moist and extend the shelf life
aerates; it aerates the food products when sugar is beaten (creamed ) with butter or whisked with eggs it helps to trap air
Bulking agent ; gives the charcteristic texture to food e.g ice cream
Preserves ; in large quanitites it creates unsiutable conditions for micro ogranisms to grow e.g jam
functions of eggs
Aeration - the whole egg and the egg white on its own are capable of trapping air - this is called aeration , when eggs are whisked , the protien streches and incorpates air bubbles into the mixture to create a foam.
Coagulation - when eggs are heated they change from a liquid to a soild and set. This is called coagulation. - the egg white starts to coagluate at 60oc but the egg yolk needs to reach a higher tempture of 65oc to start coagluation until full coagluation occures at 70oc.
Emulsification - when oil and water are forcibly mixed toghether they form what is called an emulsion. After a few mintues the oil and water will separate unless an emulsifer is added. Egg yolk contains a substance calledd Leithchin . when egg yolk is added with oil and vinger it stops the liquid seperating and is therefore known as an emulsifier.
uses of eggs
Aerate ; trap air when beaten e.g cake making
Emulsifes : eggs are used to stop oil and water seperating, they allow an emulsion to form. e.g mayonassie
enrobe: the eggs act as a glue and hold dry coating to a surface. this forms a protective barrier during cooking, e.g fish cakes
colour : this adds a glaze to the product and produces a shinny finish
enrich ; a sauce adding colour and improving the nutrtional value
Setting (coagulate) ; a mixture to hold a firm structure, e.g quiche
Bind; to 'glue' dry ingredents together. when heated the eggs, holds the ingredents toghether
Thicken ; the protien coagluates sets when heated.
types of fat - animals , fish , vegtables
Saturated and unsaturated
saturated fats are found in lard, butter, suet and some vegatable oils, e.g coconut milk and some soft spreads. they should be used sparingly as they contain more cholesterol than other fats.
Unsaturated fats are found mainly in vegtable oils, e.g cooking oils. unsaturated fats contain less cholesterol.
the fat coats the flour particles and this prevents the asorbtion of water, giving a waterproof coating.
this prevents the gluten from developing which can give an elastic and streachy texture. Gluten is formed when the protien in the flour mixes with water. if the gluten cannot form the mixture is shortened giving a characteristic, short, melt in the mouth and crumbly texture.
functions of fats
aerate: required to aerate food when creamed with sugar it helps to trap air
extend freshness : helps to extend the shelf life of baked products as it helps to keep in the moisture
flavours: adds distinct flavours and aromas to food
cooking medium; is able to act as a cooking medium for roasting foods
adds texture : it helps to achive aa flaky textyre to pastry by crating lammination and steam.
emulsions : forms emulsions such as oil and vinger in a salad dressing
colour : adds a colour / shine to baked products
shortening : gives the unqiue short crumbly texture charcteristics to foods such as biscuits
prevents lumps ; prevents lumps of flour forming eccpecially in sauces
eat well plate
the eatwell plate is the healthy eating model for the united kingdom. it is made up of the different grous and shows the balance and variety of foods we should inculde in our diet. the eatwell plate makes healty eating easier to understand by showing the types and proportions of foods we need to have a healty and balanced diet contianing all the nutirents that we need . the eatwell plate shows two of the keys to a healthy diet.
- eating the right amount of food for how active you are
- eating a range of foods to make sure you are getting a balanced diet
diabetes - diebetics need a healthy diet and have to control there intake of sugar , a there body is unable to process glucose properly
coeliac disease - this is where the person has an intolerance to the protien gluten, which is found in wheat, barley and rye products. so must be avoided
calorie controlled - the genral guidelines for a person on a calorie controlled diet are to eat more starchy foods and cut down on the fat and sugar intake
nut allergies -this is any allergy to any type of nut caused by an intolerance, and can cause an anaphylactic shock.
lactose intolerant - people with lacttose interolance cannot digest the milk sugar called lactose
vegetarians - lacto vegetarian don't eat meat , fish , eggs , poultry - lacto ovo vegetarian don't eat meat, fish, poultry - vegan don't eat any animal products - pescatarian will not eat meat, poultry.
how do they work
the action of moisture , heat or acidity or a combitation triggers a reaction with the rasing agent to produce gas
the gas expands when heated
the gas bubbles become trapped as it bubles up throught the mixture
when heated the bubbles hold form a firm structure containing a network of holes left by the expanded gas
Functions of ingredients - cake
Flour - Forms the structure of the cake , As the cake is heated, protien in the flour sets the framework and shape , Dextrinisation occurs , starch converts into sugar caramalises resutling in a golden surface.
Fat - Adds colour and flavour, Holds air bubbles (foam) which creates texture and volume , produces a short crumb or rich even texture dependent on the ratio of fat and method used , Increases the shelf life.
Rasing agents - Aerates the mixture increasing the volume and resulting in a light texture
Eggs - Trap air when whisked into a foam, Coagluate on heating , Emulsify and holds the fat in emulsion and keeps it stable, Adds flavour and nutritional value.
Sugar - Sweetens and adds flavour, When creamed with fat, helps to hold air in the mixture, Caraamelisation gives colour.
Functions of ingredients - pastry
- soft plain flour is used n short crust pastry to give crumbly texture
- strong plain flour is used in in flaky/ rough puff pastry to give the pastry elesticity
- Flour forms the structure of the pastry
- In shortcrust pastry the fat coats the flour granules resulting in a crumbly texture
- fat traps air between the layers in flaky/rough puff pastry
- adds colour and flavour
- Binds the dry ingredents
- adds flavour
- strengthens gluten
Functions of ingredients - sauce
Fat: Adds flavour which is absorbed by the flour when the saue is heated
Flavourings : These add colour, teture to the sauce e.g cheese , chilli or peppercorns
Liqiud - The main ingredent, is needed for the gelatinisation of starch, can improve the nutritional value.
Flour - when mixed with a liquid and heatedd the starch granules thicken the mixture
Salt - improves the flavour to the sauce.