Isolate starch from potatoes.

Experiment

 Object: -

 Isolate starch from potatoes.

Reference - 

1) Kokate C. K. Practical Pharmacognosy, Vallabh Prakashan; New Delhi; 4th edition (1994), pg. 142. 

2)Kokate C. K.  Pharmacognosy, Vallabh Prakashan; New Delhi; 42nd edition (2008), pg. 7.30,7.31. 

Requirements: - 

Water bath, Centrifuge, Acetic acid, Ammonium hydroxide, Methanol, Potato.

Theory:

Starch

Synonym: Amylum.

Biological source:

Starch consists of polysaccharide granules obtain from grains of maize rice wheat or from the tuber of potato.

Potato Starch:

The potatoes are washed to remove earthy matter . They are crushed or cut and converted into a slurry. Slurry is filtered to remove the cellular matter as the potatoes do not contain gluten ,they are easy to process further. After filtration the milk is slurry containing starts with purified by sand sand and washing then it is dry and send to market.

Procedure: 

1. Macerate the pieces of potato tubers with twenty parts of 5 % acetic acid for 24 h.

2. Warm to 70oC and add concentrated ammonium hydroxide drop wise and adjust the pH to 10

3. Centrifuge, wash the precipitate thrice with sufficient quantity of 1% ammonium hydroxide and recentrifuge. Discard the supernatant liquid and washings. 

4. Dry and weigh the crude solanine. Purify it by dissolving in boiling methanol, filtering and concentrating until the glycoalkaloid starts crystalling out. 

Result:

The amount of potato starch obtained is____mg.