Procedure For Define Percentage of reducing and total sugar by fehling soxhlet?
1. Standard titration (Standardization of Fehling's solution) - Titrate 10 ml of Fehling's solution (5 ml Fehling A + 5 ml Fehling B solution) against standard glucose solution as described in the previous experiments.
2. Sample titration
a) Reducing sugars
- Weigh accurately about 2 g of the given food sample (honey, jaggery) in a small beaker.
- Dissolve it in a small amount of distilled water. Quantitatively transfer the contents of the beaker to a 250 ml volumetric flask. Make up the volume in the flask to the 250 ml mark with distilled water.
- Mix well. If necessary, filter the solution through a dry filter paper into a dry flask.
- Fill the burette with this clear filtrate and titrate with 10 ml Fehling's solution.
- Calculate the percentage reducing sugar in the given food sample.
b) Total sugars
- Measure accurately 100 ml of solution of the food sample prepared above and transfer into a 250 ml conical flask.
- Add 2 ml of Conc HCl. Heat the flask in a boiling water bath for 20 minutes.
Cool the flask. Neutralize the acid with solid Na2CO3. Transfer the contents of the flask quantitatively to a 250 ml volumetric flask and make up the volume to the mark with distilled water. Mix well.
- Fill this solution in the burette and titrate against 10 ml Fehling's solution.
- Calculate the percentage total sugars in the given food sample.