Carbohydrates Flashcards
Name the functions of carbohydrates
Provides bulk of energy
Acting as a protein sparer
Name the three types of carbohydrates
NSP (non starch polysaccaride)
Sugars
Starches
Name the simple carbohydrate.
Sugars
Name the complex carbohydrate
NSP
Starches
What is the chemical name for simple sugars and give 1 example
Monosaccharides
Glucose/ Fructose
What is the chemical name for double sugars give 1 example
Disaccharides
Sucrose/lactose/maltose
What is the difference between fruit and free sugars.
A fruit sugar is a natural sugar from either fruit or vegetables
A sugar that is either added or outside the cellular structure
Describe a hidden sugar.
This is a sugar that is found in foods that wouldn’t commonly be associated with having sugar for example ready meals.
What are the affects of having a high sugar diet.
Dental caries
obesity
What is the chemical name for a complex carbohydrate
Polysaccharides
Name the three most important starches and origins and function.
Starch
Mainly found in plants
Made up of many glucose molecules
Pectin
Found naturally in some fruits
Forms a gel in water and helps jam to set
has some relation to lowering cholesterol
Glycogen
Made from glucose by humans
Small amounts stored in the liver and muscles as energy reserve
Sources of starch
Root vegetables
Cereals and cereal products
Describe the affects of an Deficiency in sugars.
Lack of energy
Lower blood sugar levels
Weight loss but increase in body fat percentage
Serve weakness due to the fact that fat stores will be depleted and protein will be used for energy
Describe the affects of excess sugars in the diet
If not used by the body will be stored as fat
Could led to obesity and obesity related health issues
Give some examples of dietary fibre sources
Wholemeal products
Fruits and vegetables with skins not removed for example apples and potato
Name the functions of dietary fibre
Healthy digestive system
Weight control
Helps to prevent bowl disease
Soluble dietary fibre can help to lower cholesterol
Name the two types of fibre
Soluble and insoluble
Desribe the functions of soluble fibre
Slows digestion and absorption of carbohydrates
Helps control blood sugar levels
Can reduce blood cholesterol
List some sources of Soluble fibre
Oats
nuts
legumes(beans)
Describe the function of Insoluble fibre and give the recommended consumption amount
Cannot be broken down by the body
Absorbs water
Adult = 30 grams
Give some sources of Insoluble fibre
Wholegrain foods, brown rice
Fruits and vegetables with skin still on
Nuts and seeds
Describe the affects of excess dietary fibre and the affects of Deficiency
Will limit the absorption of iron and calcium
Constipation
Could increase the risk of bowl cancer
Describe the starch Amylose
Simplest form of starch.
Made up of 300 glucose units.
They are a straight chain of α-glucose units.
They form a helix (spiral) because of their angled bonds.
Has bonds between carbon 1-4. This is its Glyosidic link. In this process water is expelled.
O-O-O-O-O-O-O-O
Each one above represents an Alpha glucose
Describe the starch Amylopectin
More complex structure and larger than amylose.
Made up of shorter chains of α-glucose with many branches.
Often has many thousands glucose units.
Has 1-4 bonds in order to form the overarching structure but to make Amylopectin also has 1-6 bonds to form the branches.
80 % of starch found in plants is Amylopectin
What happens to a starch based sauce when either lemon juice sugar are present.
The presence of acid for example lemon juice this reduces the strength of the gel and instead forms a vicious paste by hydrolysing the starch.
The presence of sugar means that the gels strength reduces the strength of the gel as it competes with the starch therefore reducing the overall viscosity.
Describe Gelatinisation
This is the process where starch molecules are heated at between 60 and 80 degrees and for completion of the process 100. At 60 degrees the starch molecules absorb liquid and swell up to 4 times their size then at 80 degrees the starch pops and realises both amylose and amylopectin and then at 100 degrees the process is fully completed.
Describe Retrogradation of Starch
This is the process of starch reverting back to its original structure after it being damaged and water being released this commonly happens with frozen food that needs to be thawed that contain starch.
Why use a modified starch?
- Increased stability
- Change in their appearance
- Change in their Viscosity
- Modified starch can be used in order to replace fat in foods. As it can perform the same function without the health drawbacks
- Alter the gelatinisation time commonly to be lower
What special types of Gels can be formed with a modified starch?
- Soft gels
- Quick forming gels
- Stable gels
- Gels that retrograde less easily
- Gels with good freeze-thaw properties
