Tag: nutrients and foodstuffs

Questions Related to nutrients and foodstuffs

Which of the following foods turns blue-black with iodine solution?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Milk

  2. Groundnut

  3. Tomato

  4. Raw potato

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Correct Option: D
Explanation:

  • Raw potato contains approximately 17% starch. when iodine solution added to the raw potato sample, it turns blue-black. Iodine reacts with the starch present in the raw potato which results in the formation of blue-black colored complex. 

Hence option D is the correct answer.

Egg white, turns violet when two drops of copper sulphate and ten drops of caustic soda is added to it. This indicates the presence of 

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Starch.

  2. Proteins.

  3. Fats.

  4. Vitamins.

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Correct Option: B
Explanation:

When two drops of copper sulphate and ten drops of caustic soda or NaOH is added to egg, it turns violet. This indicates the presence of proteins.
This is Biuret's test and the principle is simple as follows:
In the presence of alkaline medium (caustic soda or NaOH), the Cu2+ ions get reduced to Cu+ and binds to the egg proteins, thereby giving a violet color.
Therefore, the correct answer is option B.

Which of the following agent is used to detect the presence of fat in the food product?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Methyl alcohol

  2. Ethyl alcohol

  3. Sodium hydroxide

  4. Iodine solution

Show answer
Correct Option: B
Explanation:

Shake or crush the food to make it dissolve. Filter or dilute the food and ethanol mix so that you get a clear liquid (a solution of fat in ethanol). Add this to a test tube of water. A white (milk-like) emulsion indicates the presence of fats or oils.

So, the correct option is 'Ethyl alcohol'.

'Oil' is a mixture of different

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Parafins

  2. Hydrocarbons

  3. Nutrients

  4. Gases

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Correct Option: B

Starch is tested with ................  solution.

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Caustic soda

  2. Salt

  3. HCl

  4. Iodine

Show answer
Correct Option: D
Explanation:

The iodine test is used to test for the presence of starch. Iodine dissolved in an aqueous solution of potassium iodide reacts with the starch, producing a purple-black colour. The intensity of the colour decreases with increasing temperature and with the presence of water-soluble organic solvents, such as ethanol.

What compounds form fats and oils?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Carboxylic acids +Alcohol

  2. Carbon Compounds +water

  3. Carbon Dioxide + Alcohol

  4. Carbon Monoxide +Alcohol

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Correct Option: A

Which of the following is used to test presence of starch?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Cheek peel

  2. Onion

  3. Potato

  4. None of the above

Show answer
Correct Option: C
Explanation:

A chemical test for starch is to add iodine solution (red) and see if it turns blue/black in colour. It is possible to distinguish starch from other carbohydrates using this iodine solution test. For example, if iodine is added to an peeled potato then it will turn black. 

Which of the following test are used for detection of protein?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Biuret test

  2. Iodine test

  3. Protein test

  4. Glucose test

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Correct Option: A
Explanation:

The Biuret test is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper (II) ion forms violet-coloured coordination complexes in an alkaline solution. The Biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. 

Choose the correct answer from the alternatives given.
If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra.tissue, which is the best molecule for storage?

evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

  1. Fructose and glucose in the form of honey

  2. High-calorie fat molecules

  3. Complex cellulose molecules

  4. Glycogen with extensive side branches of glucose

Show answer
Correct Option: B
Explanation:

If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra tissue, then high-calorie fat molecules are the best molecules for storage. So, the correct answer is "high-calorie fat molecules".

Oil is obtained from the plant and animal sources can be detected by 

evs food for health simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

  1. Oil paper test

  2. Starch

  3. Calcium sulphate solution

  4. Iodine solution

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Correct Option: A
Explanation:
Some plants and animal produce oil. Oil paper test is a test used to detect oil in plant and animal products. It include a process in which a paper is moved back and forth few times against the substance and the presence of oil on the paper is checked.
So the correct answer is 'Oil paper test'.