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(d) Determination of Crude Fibre
Practical 1-Proximate composition analysis of feed ingredients and prepared feeds
(d) Determination of Crude Fibre
Principle
The moisture and lipid free sample is digested first with a weak acid solution followed by weak base solution. The organic residue is collected in a filter crucible and the loss of weight during ignition is noted as fibre.
Reagents
Weight and transfer about 1g of lipid free sample (W0) into a clean glass crucible. Fix the crucible into a fibre tech hot extraction unit. Maintain continuous flow of water through the condenser. Add 150ml of boiling 0.128M of H2SO4 into the column tubes. Switch on the heater to the maximum point. Add 3 drops of octonol to prevent foaming and boil for 30 minutes, drainout from the column. Wash the sample in the colony with boiling distilled water thrice by using about 30ml of water each time.
Remove water completely after each wash. Add 150ml of boiling 2.023M of KOH and about 3 drops of octonol. Boil as mentioned above for another 30 minutes. Filter and wash as followed earlier 3 times with hot water. Dry the crucible at 100°C over night or at 130°C for 2 hours. Cool the crucibles in a dessicator and note down the weight (W1).
Ignite the crucible at 500°C for atleast 3 hours in the muffle furnace. Allow the furnace to cool down at a room temperature and take the weight (W2).
Calculation
The moisture and lipid free sample is digested first with a weak acid solution followed by weak base solution. The organic residue is collected in a filter crucible and the loss of weight during ignition is noted as fibre.
Reagents
- Sulphuric acid solution (0.128 M): Dilute 6.8ml of Conc. H2SO4 TO 1 litre of distilled water.
- Potassium hydroxide solution (0.223 M),
- n-Octonol (antifoaming agent),
- Fiber tech system,
- Muffle furnace,
- Hot air oven,
- Dessicator,
- Weighing balance
- Volumetric flask
- Glass crucibles
Weight and transfer about 1g of lipid free sample (W0) into a clean glass crucible. Fix the crucible into a fibre tech hot extraction unit. Maintain continuous flow of water through the condenser. Add 150ml of boiling 0.128M of H2SO4 into the column tubes. Switch on the heater to the maximum point. Add 3 drops of octonol to prevent foaming and boil for 30 minutes, drainout from the column. Wash the sample in the colony with boiling distilled water thrice by using about 30ml of water each time.
Remove water completely after each wash. Add 150ml of boiling 2.023M of KOH and about 3 drops of octonol. Boil as mentioned above for another 30 minutes. Filter and wash as followed earlier 3 times with hot water. Dry the crucible at 100°C over night or at 130°C for 2 hours. Cool the crucibles in a dessicator and note down the weight (W1).
Ignite the crucible at 500°C for atleast 3 hours in the muffle furnace. Allow the furnace to cool down at a room temperature and take the weight (W2).
Calculation
Last modified: Monday, 23 May 2011, 9:42 AM