Carbohydrates - created from Mind Map

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Definition

Importance

Monosaccharides

Classification of CHO

Dietary Fiber

Oxidation Reaction

Interaction with water

Retrogradation of amylose

Syneresis

Hydrolysis

Browning reactions

Caramelization

Maillard Browning

Pyrolysis

Consist of polyhydroxy aldehydes or ketones

3 Elements: C - Carbon, H- Hydrogen & O - Oxygen

Source of energy

Building blocks

Components of other molecules

Glucose

Starch in plants

Plant : Cellulose

Human : Glycogen

DNA

RNA

Glycolipids

Aldose/Ketose

No. of carbons in chain

Chiral carbon

Fisher Projections

Chiral objects

Archiral objects

Ways to represent mirror image in 2 dimensions

Cannot be superimposed on their mirror image

Hand

Gloves

Can be superimposed on the mirror images

Drinking glass

Cubes

Monosaccharides

Disaccharides

Polysaccharides

Oligosaccharides

1 polyhydroxy aldehyde/ketone

Single sugars

Colorless, water-soluble & crystalline solids

Sweet taste

Glucose Anomers

Fructose Anomers

Importance

Glucose

Xylose

Forms are anomers of each other & carbon-1 called the anomeric carbon

Closes on itself to form a furanose ring

β-D-glucose

β-D-fructose

β-D-ribose

β-D-galactose

β-D-deoxyribose

dextrose & blood sugar

Metabolized in the body for energy

Other sugar : must be converted to glucose by the liver

levulose & fruit sugar

Sweetest

ribonucleic acid (RNA)

Glucose into lactose

deoxyribonucleic acid (DNA)

2 monosaccharides

Glycosidic Bonds

Importance

Covalent bond that joins a carbohydrate to another group

Sucrose

Maltose

Lactose

Table sugar

Caramel formed from heating sucrose

Invert sugar : produced by hydrolysis of sucrose under acidic conditions

Malt sugar

Produced in germinating grain

Formed during the hydrolysis of starch to glucose during digestion

Milk sugar

Digested by enzyme lactase

More than 2

Starch

Polymer consisting of D-glucose units

Amylose

Amylopectin

Glycogen

Cellulose

Chitin

Long, unbranched chains of glucose

Flexible to allow the molecule to twist into the shape of helix

Long chains of glucose

Animal starch

Abundant in the liver & muscles

Maintains normal blood sugar level & gives energy

Long,unbranched chains of D-glucose connected by β(1→4) glycosidic

Important structural

Polymer of N-acetylglucosamine

Extremely strong

3 - 10 monosaccharides

Raffinose

Trisaccharide

Found in beans, cabbage, broccoli etc

Hydrolyzed to D-galactose & sucrose by the enzyme α-galactosidase

Galactose

Fructose

Glucose

Important

Complex mixture

Resistant to hydrolysis by endogenous enzymes

Types

Cellulose

Beta-Glucans

Lignin

Pectins

Hemicellulose

Chitin/Chitosan

Plant Gums

Insoluble in water

Low-calores foods : bulking & rheological

Linear polymer of glucose with beta : 1-4 links

Glucose polymers contains both beta : 1-3 links & beta 1-4 links

Less linear, more soluble than cellulose

Contribute viscosity of products

High complex nonpolysaccharide

Insoluble

Polymer galacturonic acid bounded by alpha : 1-4 galacturonic links

Produce strong gels

Heterogenous

Different sugars in backbone & side chain

Soluble in dilute alkali

Improve water binding in baked goods

Poly beta, 1-4 acetyl-D-glucosamine

Cellulose-like constituents

Deacetylation of chitin = chitosan

Water-soluble polysaccharides

Contribute : viscosity/gelling properties

Thickening agents

Test for reducing sugars

See colour changes

Formation of sugar alcohol

Sucrose with water become solubilize

Starch with water won't be solubilize

Apply heat/ stir it to increase the solubility rate

Colour changes from opaque to translucent

Water will be secreted from the carbohydrate

Preservation techniques

Enzymatic: Oxygen + Phenolic + PPO

Nonenzymatic: Caramelization

Process

Influenced by pH

Direct heating

Anomeric shifts, alteration of ring size & breakage of glycosidic bonds

Dehydration

Formation of anhydro rings, double band formation

Color & flavour

Carbohydrate + Protein

Why we need to control

Loss of amino acid

Dark colour, strong flavour & odour

Toxicity of product

Total loss of water from sugar molecule

Ex: Burnt & inedible flavor