Question

Why is gelatin negathve for millon's test?

Answer 1

In reduced sulfur test, all samples give positive result except for gelatin. In the positive result, black or grey precipitates were formed to represent the presence of sulfur amino acid. Basically, it is a reaction between lead (II) acetate with the sulfur presents in the sample. NaOH solution was added to break the bond enable the sulfur to react. Upon boiling with NaOH, it yield sodium sulphide. This reaction is due to partial conversion of the organic sulphur to inorganic sulphide, which can detected by precipitating it to lead sulphide, using lead acetate solution. (Vishwa, 2011).Note that the albumin cannot be heated in a long period of time as it will coagulated and affected the result. Meanwhile, sulfur of gelatin present as methionine not reacted in this test thus showing negative results.In ninhydrin test, all samples show positive results which produce lavender colour solution. This positive reaction indicate the compound contain at least one free amino group and one free carboxyl group. However there were exception of proline and hydroxyproline which will produced yellow product which is not occur in the result. In the alkaline condition,all α- amino acids react with ninhydrin (triketohydrindene hydrate), a powerful oxidizing agent to give a purple colored product (diketohydrin) termed Rhuemann’s purple. Besides amino acids, other complex structures such as peptides, peptones and proteins also react positively when subjected to the ninhydrin reaction.From the overall result, it show that the samples Egg white powder, gelatin , wheat flour, soy bean powder and milk powder were protein qualitatively through the positive colour reaction.



Answer 2

Answer:

Gelatin exists as a protein made from animal collagen, usually from cows and pigs.

Explanation:

Gelatin exists a protein formulated by boiling skin, tendons, ligaments, and/or bones with water. It exist usually obtained from cows or pigs.

Millon's test is provided by proteins containing phenolic amino acids. Gelatin does not provide this test. First, a white precipitate is created when proteins exist treated with millions of reagents and then turns to brick-red color on boiling, this confirms the presence of proteins.

The formation in this test color exists due to the presence of the indoyl group. Gelatin does not react to this test due to a lack of amino acid tryptophan.

Gelatin exists as a protein made from animal collagen, usually from cows and pigs. It's commonly utilized to make capsules, cosmetics, ointments, and foods. Collagen exists one of the materials that create cartilage, bone, and skin. Taking gelatin might improve the production of collagen in the body.

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