Here are the sources and chemical tests for Indian gum, pectin, black catechu, ricinous oil, and gelatin:



1. Indian Gum (Gum Acacia)

Source:

  • Derived from the sap of Acacia trees, primarily Acacia senegal and Acacia seyal.

Chemical Tests:

  • Solubility Test: Dissolve a small amount of gum in water. It should form a viscous solution.
  • Mucilage Test: Add a few drops of the solution to a glass of water. It should form a slimy, mucilaginous mass.
  • Molisch’s Test: Add a few drops of Molisch’s reagent (alpha-naphthol solution in alcohol) and then a few drops of concentrated sulfuric acid along the side of the test tube. A purple or reddish-violet ring at the interface indicates the presence of carbohydrates.

2. Pectin

Source:

  • Extracted from the cell walls of fruits, especially apples and citrus fruits.

Chemical Tests:

  • Gel Formation Test: Mix pectin with sugar and acidic solution (like lemon juice) and heat. It should form a gel-like structure upon cooling.
  • Alcohol Precipitation Test: Add ethanol to an aqueous solution of pectin. Pectin will precipitate out as a white gel.
  • Color Reaction with Carbazole: Add a few drops of carbazole solution and concentrated sulfuric acid to the pectin solution. A red color indicates the presence of pectin.

3. Black Catechu (Cutch)

Source:

  • Extracted from the heartwood of Acacia catechu.

Chemical Tests:

  • Ferric Chloride Test: Add a few drops of ferric chloride solution to an aqueous solution of black catechu. A greenish-black or blue-black color indicates the presence of tannins.
  • Goldbeater’s Skin Test: Soak a piece of goldbeater's skin in the catechu solution, wash with distilled water, and then immerse in a 1% solution of ferrous sulfate. A blue-black coloration indicates tannins.
  • Vanillin-HCl Test: Add vanillin solution in concentrated hydrochloric acid to the catechu solution. A pink or red color indicates the presence of catechins.

4. Ricinous Oil (Castor Oil)

Source:

  • Extracted from the seeds of the Ricinus communis plant.

Chemical Tests:

  • Solubility Test: Ricinous oil is soluble in alcohol and chloroform but not in water.
  • Baudouin Test: Mix the oil with an equal volume of hydrochloric acid and a few drops of 2% solution of phloroglucinol in alcohol. A pink color indicates the presence of castor oil.
  • Hydroxyl Value Test: This test measures the hydroxyl content in the oil, which is high for ricinous oil due to the presence of ricinoleic acid.

5. Gelatin

Source:

  • Obtained by hydrolysis of collagen, found in animal bones, skins, and connective tissues.

Chemical Tests:

  • Biuret Test: Add a few drops of sodium hydroxide and a few drops of copper sulfate solution to the gelatin solution. A violet or pink color indicates the presence of peptide bonds.
  • Xanthoproteic Test: Add concentrated nitric acid to the gelatin solution and heat. A yellow color forms, which turns orange upon adding ammonia, indicating the presence of aromatic amino acids.
  • Gel Test: Dissolve gelatin in warm water and let it cool. It should form a gel upon cooling.