1. Determination of Carbohydrate
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2. Carbohydrate in food
Carbohydrate exist especially in food of plant source
In plant, carbohydrate formed by photosyntesis process, reaction of CO2 and H2O with sunray assistance
Carbohydrate contributes to character of food, i.e : taste, color and texture
Some classes of carbohydrate produce fibers (dietary fiber) which has good function in digesting.

3. Carbohydrate in Human Body
Carbohydrate is cheap calory source  main calory source
Carbohydrate in human body contributes to:
- Avoid ketosis
- Avoid over protein decomposition in human
body
- Avoid mineral lost
- Help fat and protein metabolism
In human body carbohydrate formed of several amino acid and part of fat glycerol

4. STRUCTURE OF CARBOHYDRATE
Carbohydrate molecule consist of Carbon (C), Hiyrogen (H), and Oxygen (O). These unsure combine in chemical bonding with the common formula Cm(H2O)n. Number of m and n various depend on the type of carbohydrate
Monosaccharide and disaccharide have sweet taste caused by the hydroxyl group.
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5. Classification of Carbohydrate
Monosaccharide
Simple carbohydrates  cannot be hydrolyzed
They are aldehydes or ketones with two or more hydroxyl groups
Oligosaccharide
Composed of longer chains of monosaccharide units
Contain between two and ten monosaccharide units
Polysaccharide
Contain greater than ten monosaccharide units
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6. Classification of Monosaccharide
Placement of its carbonyl group
Aldose,
If the carbonyl group is an aldehyde
Example : Glucose, Galactose
Ketose,
If the carbonyl group is a keton
Example : Fructose
Number of carbon atoms it contains
Trioses, 3 carbon atoms
(glyceraldehyde, ketotriose)
Tetroses, 4 carbon atoms
(Erythrose, Threose)
Pentoses, 5 carbon atoms
(Ribose, Arabinose, Xylose, Ribulose, etc)
Hexoses, 6 carbon atoms
(Glucose, Galactose, Fruktose)
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7. Reducer Sugar
Reducer sugar is class of sugar which could be oxidized by weak oxidizing agent as Tollens, Fehling, Barfoed reagent, etc.
Oxidation product of aldehide or aldose group is polyhydroxy carboccilic acid, called aldonic acid
Aldose or ketose could be reduced by carbonyl reducing agent
Reducing property of sugar used in :
- Qualitative analysis to identify carbohydrate
- Quantitative analysis  to determine the content
of carbohydrate in sample
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8. Identification of Carbohydrate
Reagent
Identification for
Object
Molish, -naphtol in conc.H2SO4
Carbohydrate present
Purple colored layer
Fehling, basic solution of Cu2+
Reducer sugar present
Cu2O, brick red colored precipitate
Benedict, basic solution of Cu2+
Barfoed, acidic solution of Cu2+
Tollens, basic solution of Ag+
Ag2O silver mirror
Selliwanof, Recorcinol in conc. HCl
Ketose present
Cherry red colored solution
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9. Determination of Carbohydrate
Quantitative carbohydrate analysis based on the ability of aldehyde or ketone group -of monosaccharide unit- to be oxidized by weak oxidizing agent like Cu 2+ in basic solution.
According to this property, there are 2 method for determination of carbohydrate :
- Luff Schoorl Method
- Muller Method
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10. Luff Schoorl Method for Determination of Carbohydrate
Before Invertion
To determine the reducer sugar (Monosaccharide) content
Weak Invertion
To determine non reducer sugar (Disaccharide) content
Strong Invertion
To determine starch (Polysaccharide) content
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11. Determination of Monosaccharide
Weighing
Dissolving
Measured transferring and Luff Schoorl adding
Reflux 10’
KI and acid adding
Titration with Na2S2O3
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12. Determination of Disaccharide
Reflux 10’
Weighing
Diluting
Weak invertion 25% HCl (70oC)
1 hour
Measured transferring & Luff Schoorl adding KI
and acid adding
Titration with Na2S2O3
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13. Determination of Disaccharide
Reflux 10’
Weighing
Diluting
Weak invertion 25% HCl (100oC)
3 hour
Measured transferring & Luff Schoorl adding KI
and acid adding
Titration with Na2S2O3
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14. Thank You
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