Subhashini, M H and Ravindranath, M H (1981) Proteins. CMFRI Special Publication (7). pp. 31-41.


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The nitrogen of the protein precipitate is converted to acid ammonium sulphate by digestion with sulphuric acid and various catalysts. On making the reaction mixture alkaline, ammonia is liberated, which is removed by steam distillation. The ammonia liberated by steam distillation is gathered in acid solution containing an indicator. Change in pH of the acid solution due to addition of ammonia is indicated by the indicator dye. This solution is back-titrated with 0.01 N HCI, and the original acidic condition indicated by the indicator dye, is taken as the end point. The amount of HCl consumed in back titration is proportional to the amount of ammonia liberated. Percentage of nitrogen is calculated from the titre value, which is converted into gm% of protein present in sample by multiplying the percentage nitrogen with a factor 6.2S. The factor 6.25 is used for conversion because in average, protein contains 16% of nitrogen.

Item Type: Article
Uncontrolled Keywords: Proteins; Crustacean Biochemistry and Physiology
Subjects: Crustacean Fisheries
Fish and Fisheries > Biochemical Study
Divisions: Contributors
CMFRI-Cochin > Marine Capture > Crustacean Fisheries
Depositing User: Geetha P Mrs
Date Deposited: 24 Sep 2010 06:09
Last Modified: 09 Sep 2015 15:20

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